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- Front Matter: Volume 10833
- Molecular Spectroscopy And Atmospheric Radiative Processes
- Optical Radiation Propogation In The Atmosphere And Ocean
- Optical Investigation Of Atmosphere And Ocean
- Physics Of The Troposphere
- Physics Of The Middle And Upper Atmosphere
Front Matter: Volume 10833
Front Matter: Volume 10833
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This PDF file contains the front matter associated with SPIE Proceedings Volume 10833, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.
Molecular Spectroscopy And Atmospheric Radiative Processes
Simulation of the atmospheric transfer of solar radiation in the visible spectral region
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The atmospheric transmission has been calculated using different spectroscopic data in the 400–700 nm region. The new absorption cross sections of O3 and NO2 are considered. The H2O absorption lines from modern spectroscopic databases are taken into account and the solar radiative fluxes, measured by ground-based photometers with filters in the visible wavelength bands, are simulated.
Time-resolved Fourier transform infrared spectroscopy and updated system of neutral oxygen (O I) levels
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We present the results of precise laboratory measurements of the infrared (IR) spectrum of neutral oxygen (O I) atom using the time-resolved IR Fourier transform spectroscopy technique in 800−13000 cm−1 range. Based on 135 measured lines (including 51 lines previously not observed in the laboratory) and taking into account all previous measurements of the O I spectrum, a reoptimization procedure was performed, resulting in an updated system of levels internally matched to an accuracy of at least 0.01 cm−1. A large array of oscillator strengths and transition probabilities is calculated in the considered spectral range.
Interaction potential of H2O molecules and water layer adsorbed on surface of aerogel nanopores
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Modeling of the water layer on the surface of airgel nanopores has been carried out. The interaction potentials between incident water molecule and water molecule adsorbed on the nanopore surface were calculated by the use B3LYP/6-31 + G (d) method. An analytical form of the isotropic potential was obtained.
Chemical kinetics equations describing water complex formations
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Small sets of chemical kinetics equations describing the formation of complexes in water vapor in the particular case of a system containing four molecules of water (monomer) with reaction rates equal to 1 are investigated. The steady state of the system is a stable focal point in the monomer-dimer plane and a complex singular point in the trimer-tetramer plane. The algorithm for deriving equations in the case of arbitrary number of monomers is described, convenient for program realization.
On estimation of the local line contribution in IR spectra of H2O and CO2
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The results of calculations of the H2O continuum absorption coefficients for IR spectra in 1000-1300 cm-1 and 2000-2700 cm-1 regions and absorption coefficients in the wings of the CO2 bands in the IR spectrum are presented. It is shown that the calculation of the local line contribution to the total absorption should be related to the line shape so that the maximum boundary of local line contribution does not fall into the region of frequency detunings corresponding to the exponential decay. The tendencies to a change of the continuum absorption with variations in the local line contribution boundary remain the same in cases of using both the experimental coefficient and calculated according the asymptotic line wing theory as the total absorption coefficient.
Interpretation of the water vapour continuum absorption spectra in 0.94 and 1.13 micron bands taking into account the contribution from intermediate line wings
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This paper presents results of the study of the water vapour continuum absorption within 8800 and 10600 cm-1 absorption bands. The continuum spectra recorded at increased temperatures (398, 431, and 471 K) and pressures are discussed on the basis of water dimer model1 supplemented by a contribution of intermediate line wings according to the model2 . The values of semiempirical parameters that characterize contribution and effective spectral width of the intermediate line wings are derived from fitting to the experimental continuum absorption spectra. A preliminary analysis of the temperature and pressure dependences of the fitted parameter is performed. It is shown that a better agreement between the simulated and experimental continuum spectra can be reached both within centre and in close wings of the absorption bands when intermediate line wings are accounted according to the model2 .
Radiative effect of different aerosol types in clear sky conditions according to COSMO-Ru model
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The radiation effects of aerosol in clear sky under continental aerosol (Meteorological Observatory of MSU (Russia), Lindenberg Observatory (Germany)), over semi-desert areas (Israel) and Arctic district at the Tiksi International Hydrometeorological (Russia) observatory were estimated using the mesoscale COSMO-Ru model. The effect of aerosol on the surface air temperature is also was investigated. For the present study we use the aerosol dataset from CIMEL (AERONET) sun photometer measurements and the data of shortwave radiation components based on reliable instruments Kipp&Zonen. The application of the new MACv2 climatology radiation model provides the annual average relative error of the total global radiation which does not exceed 25 W/m2. We suggest that in clear sky conditions the sensitivity of air temperature at 2 meters to aerosol in all considered geographical areas lie within 0.9°C per 100 W/m2 change in shortwave net radiation changes.
The 12CH4 absorption spectra at 296 K and 200 K in the range between 6000 and 9000 cm-1
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The 12CH4 absorption spectra in the range between 6600 and 12000 cm-1 have been recorded at 296 K and 200 K by the Fourier spectrometer IFS – 125M at pressures from 11 to 300 mbar, and spectral resolution 0.03 cm-1. Low temperature cell with a length of 220 cm was used, which provided the threshold sensitivity to absorption of the order of 10-7 cm-1. Empirical values of the lower state energy level were derived from the intensity ratios of the lines measured at 200 K and 296 K. Line assignment of the the 3ν3 band of the 12CH4 molecule was performed. The parameters of Voigt contour (the line center, intensity) were determined using multi-fitting procedure at 296K.
Systematization of published scientific graphics characterizing the water vapor continuum absorption: I publications of 1898–1980
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Results of the work on systematization of scientific plots characterizing the spectral functions related to the continuum absorption of water vapor are discussed. The plots systematized are available for researchers in W@DIS (wadis.saga.iao.ru) information system. The plots can be used for the comparison both between them and with userdefined computed data and measurements.
Systematization of published research plots in spectroscopy of weakly bounded complexes of molecular oxygen and nitrogen
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This paper provides the results of selective systematization of about 55 compound plots, gathered from 41 publications on weakly bounded complexes of molecular nitrogen and oxygen. This systematization enables the system to organize semantic search of the processed spectral functions and internal integration of graphical resources for each of the molecular complexes.
CF4 and (H2O)n molecular сomplexes
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Tetrafluoromethane (CF4), also known as carbon tetrafluoride is a long lived greenhouse gas (PFC-14), with life time ~ 50000 years. Actually, CF4 is an anthropogenic trace gas in the atmosphere. The main sources of this gas are high technology processes, such as aluminum production, semiconductor industry, or electrical and electronic engineering. CF4 has a strong Global Warming potential due to its high lifetime in the Earth atmosphere. However, the tetrafluoride – water reaction is not well studied. CF4 is considered to be a hydrophobic gas, but we proved that it forms stable molecular complexes with the binding energy exceeding E= 3.5 kcal/mol. Due to this molecular complex, at low temperatures, CF4 molecules can be found in water or snow. We simulated the (H2O)n (n=3,4) and CF4 molecular clusters using the DFT and MP2 techniques. Some stable configurations with positive frequencies of normal vibrations have been obtained.
Critical evaluation of measured rotation-vibration line positions of 16OH in the X2П state using Ritz method
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The results of critical evaluation of measured rotation-vibration line positions of 16OH in the X2 Π state are presented. The analysis was carried out using the fundamental Rydberg-Ritz combination principle, for the available experimental data in the spectral range 101-10358 cm-1. As a result, the precise set of 990 experimental energy levels of OH molecule in the interval 0-35665 сm-1 was obtained. Comparisons with the HITRAN and with known calculated energy levels are discussed.
The determination of transmittance, reflectivity, and absorptivity of a cloudy atmosphere with reflection
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The transfer of radiation in a stratified atmosphere is considered taking into account the effect of the underlying surface. Analytical expressions for the calculation of the transmittance, reflectivity and absorption capacity of the layered dispersed medium are obtained. It is shown that the absorptivity is strongly dependent on the stratification of the optical parameters of the atmosphere. It is established that the absorptivity of the atmosphere is the smallest with the highest concentration of contaminants in the surface layer of the atmosphere, in which case the absorptivity is weakly dependent on the distribution of absorption in the atmosphere. The presence of reflecting surfaces on the upper and lower boundaries of the atmosphere significantly enhances the absorptive capacity of the atmosphere.
Influence of radiation interaction of clouds on fluxes of radiation in the atmosphere
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The influence of the optical interaction of clouds on the radiation fluxes in the atmosphere is studied. A model and a method for calculating the magnitude of the radiation interaction under multiple re-radiation between clouds are proposed. It is shown that the radiation interaction depends in a complex way on the optical and geometric dimensions of the clouds and their optical parameters. It is established that for certain optical sizes of clouds the radiation interaction between them is maximal. The position of the maximum of the radiation interaction between the clouds is determined by the scattering phase function radiation: with an increase in the degree of elongation of the scattering phase function, the maximum moves to the region of large optical thicknesses.
Estimation of carbon dioxide broadening and self-broadening coefficients of SO2 lines
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The self-broadening coefficients and CO2-broadening coefficients of lines of the main isotope species of SO2 are estimated based on the analysis of literature data. The dependence of the self-broadening parameters on vibrational-rotational quantum numbers is evaluated. In the case of CO2 broadening, the half-widths of lines are calculated using a semiempirical method based on a parametric modification of the impact semiclassical model; the model parameters were determined from the fit to experimental data.
The VoTe room temperature H216O line list up to 25000 cm-1
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A preliminary version of the line list of dipole-allowed transition of the water molecule is presented. The line lists is created on the basis of VoTe calculations (Voronin, Tennyson et al. in preparation). The cut-of values used for this line list are: 25000 cm-1 in wave number and 10-30 cm/molecule at T=296 K in intensity. Calculated line-lists are available on the site ftp://ftp.iao.ru/pub/VTT/VoTe/.
Automated system for control of geodynamic processes
V. F. Gordeev,
S. Yu. Malyshkov,
M. M. Kabanov,
et al.
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This article presents the method of logging the earth’s natural pulsed electromagnetic noises for mapping anomalies of the earth's crust stress-strain deformed state. Methods for identifying small-scale space-time variations of the earth's natural electromagnetic field at global and regional scale are proposed. The paper describes an automated system for controlling geodynamic processes based on the systematization and processing of the earth’s natural pulsed electromagnetic noises recorded by ground-based multichannel geophysical loggers. The developed software downloads data obtained by registrars to the system database, allows to remotely configure the system hardware, allows to identify and authenticate the groups of researchers. It also provides researchers with the means to sample the required data and to process it mathematically in order to monitor the geomagnetic situation and identify dangerous geological processes, provides visualization of processing results and is capable of exporting specific data for further analysis in other software environments.
Photosynthetic activity of plankton and assessment of gross primary production from measurements of CO2 concentration in surface and bottom water of the Lake Baikal coastal zone
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The seasonal dynamics of the СО2 gas exchange process in the atmosphere-water system is formed as a result of combined action of hydrometeorological conditions and biological rhythms on photosynthesis (production) and destruction of organic matter. The diurnal dynamics of the coefficient of photosynthetic activity, phytoplankton population, and the carbon dioxide concentration in water is analyzed. The Gross Primary Production is estimated with the DIEL method (calculation from the diurnal dynamics of СО2 concentration) in the surface and bottom water of the Baikal coastal zone in the open-water period for three measurement cycles. It is shown that the productivity decreases in the coastal zone from June to December. In terms of the carbon С concentration, it varies from 0.9 to 0.17 mg·dm-3·day-1
Peak intensities of methane Raman bands as a function of pressure
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Spectroscopic methods for pressure determination of methane-containing gaseous medium are discussed. The results of investigation of changes in the relative peak intensities of the main methane Raman bands in the pressure range 1-55 bar are presented. New methods for the non-contact pressure determination of methane-containing gaseous media are proposed.
Estimation of contribution of water vapor continuum absorption to radiative balance of the atmosphere in cloudy conditions
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The atmospheric radiative fluxes and cloud radiative forcing are simulated with use of different models of water vapor continuum absorption and cloud optical depths. The effects of radiative heating and cooling of the cirrus cloudiness are analysed. A contribution of water vapor continuum absorption to the atmospheric radiative transfer is estimated. It is shown that sign of cloud radiative effect depends on choice of water vapor continuum model.
Virtual research environment supporting applied meteorology and climatology problem solving
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Virtual Research Environment aimed at solving applied problems requiring reanalyzes and climatic projections data is presented. The environment is based on the three-levels information system. Specially discussed is integration into the Virtual Research Environment under development of a decision support system employing an ontology knowledge base aimed at facilitation of related to climate change impact applied tasks solving.
Retrieving the 13CO2/12CO2 isotopic ratio from high resolution ground-based FTIR measurement in Tsukuba
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In the current research we describe an attempt to retrieve the 13CO2/12CO2 isotopic ratio from high resolution ground-based FTIR measurements of atmospheric transmittance spectra recorded with the Bruker IFS 125HR instrument in Tsukuba, Japan. We discuss the retrieval approach, present the obtained results, that demonstrate a seasonal cycle with an amplitude not typical to atmospheric 13CO2/12CO2, and discuss major pitfalls of the retrieval.
Siberian smoke haze over Europe in July 2016
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An analysis of smoke haze over Europe in July 2016 caused by the wildfires in Siberia has been carried out. Surface air pollution by aerosols in Moscow region during the smoke event was also investigated. It was found that optical and microphysical characteristics of the smoke aerosol in Europe were typical for the boreal forest fires. The aerosol radiative forcing (ARF) variations at the top of the atmosphere (TOA) and the bottom of the atmosphere (BOA) during the smoke haze period were analyzed. The regional mean direct radiative forcing of aerosols at the TOA and BOA on 26 July 2016 were estimated to be -25 and -45 W/m2 respectively. Probability distribution function of ARF values at the TOA was presented.
Software complex for information support of computationally difficult tasks
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The paper describes a software complex for designing a horizontally-scalable distributed information-calculation platform with loosely coupled calculation nodes. The platform is intended information support for parallel processing of multi-dimensional data and large time series. The technological scheme for platform design and deployment includes a cluster of processing nodes and a cluster of storage nodes which provide their services if requested by researcher. The main node of each cluster is the command center. Storage management center coordinates functional data processing according to instructions received from researchers. Applications are designed as jnlp-files which ensures their functionality on research terminals.
Knowledge base on the parameters of cryolithic zone located in-between rivers Ob' and Enisei
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A prototype of an information computer system for decision making support is described. The system is based on a simple 1D model of non-stationary thermal conductivity for the calculation of detailed temperature profiles from the permafrost depth. Numerical forecast data on the temperature near the Earth's surface from the databank of IMCES SB RAS are used as boundary conditions. An approach to the correct choice of climatic and meteorological quantities from the databank during the solution of applied climatic problems is considered separately. Incorrectness is due to semantic uncertainty, both of data in the databank and in the intensional of input data required for solution of applied problems. For this choice, we suggested to use the formalized taxonomy of WMO meteorological parameters in the form of OWLontology. A version of this ontology is presented, which is used for the work with the databank of IMCES SB RAS and solution of a number of some applied problems. Output data (numerical simulation results) are represented in the information computer system in the form of an ontological knowledge base, used for the decision making support.
Retrievals of the atmospheric methane content with use of new spectroscopic absorption line parameters
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The atmospheric solar spectra are simulated using new data on methane absorption lines. A comparison of the simulated spectra with the atmospheric spectra, measured by a ground-based Fourier spectrometer in the methane absorption bands in the near-infrared spectral region, is carried out. The atmospheric column-averaged volume mixing ratio of methane is retrieved from the measured spectra.
The sources of radioactive contamination in the southeast of the Tomsk region
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In the paper, the radioactive situation in the southeast of the Tomsk region is analyzed. The Siberian chemical combine has the greatest impact in environmental radioactivity. Areas with increased radionuclide concentrations are identified. On the example of the Tugansk deposit in the Tomsk region, the analysis of "radioactivity markers" is carried out according to data of various sources. The energy characteristics of potassium-40 in the subsoil layer of the air have been calculated. The method of remote detection of placers of uranium-thorium deposits is theoretically justified.
Raman intensities of nitrogen and oxygen under high pressure
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The work deals with the effects that lead to changes in Raman intensities of nitrogen and oxygen as their pressure increases. It was found that when these gases are compressed up to 80 atm, the intensities of their rovibrational Raman bands per molecule increased by approximately 3%. A theoretical model is proposed for describing Raman intensities in high-pressure gaseous media.
The influence of the accuracy of spectral line parameters of SO2 and NO2 in applications of atmospheric remote monitoring
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This article presents the results of a comparative analysis of the absorption spectral line parameters lists for SO2 and NO2 molecules with the HITRAN2016 database [1] between 2500 and 5600 cm-1. The numerical simulation of atmospheric transmission spectra of trace gases and lidar signals for a near-surface tropospheric path for detection [2] in the considered spectral range was performed.
Collection of published plots on water vapor absorption cross sections
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The work done on the systematization of water molecule absorption cross-sections in W@DIS information system is reviewed. The collection of the water molecule spectral functions, GrafOnto system for working with collections of spectral function plots, and basic plot properties are briefly described. Examples of representations of different plot types for water vapor spectral functions are given.
Optical Radiation Propogation In The Atmosphere And Ocean
Long-range filaments producing upon ultrashort mid-IR laser pulses train filamentation in air: numerical simulations
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Results of numerical simulation of self-action in air of a sequence of ultrashort laser pulses with a carrier in the near and mid-IR regions are presented. We show that the use of a 10.6-μm pulse train allows significant elongation of the plasma channel generated during pulse filamentation and enhancement of its spatial connectivity. The filamentation of a submicron pulse train does not visibly change filamentation region parameters.
Coherence of the pseudo-Bessel beams propagating in turbulent atmosphere
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Coherence of the pseudo-Bessel optical beams during propagation in turbulent atmosphere are investigated. An analytical solution of the equation for the second-order mutual coherence function of the optical radiation field, which was obtained from paraxial approximation of the scalar wave equation, is considered. The modulus of the complex coherence degree (coherence degree), the phase of the complex coherence degree, the coherence radius, and the integral scale of the coherence degree of a Bessel-Gaussian optical beam and a conic optical wave are developed for different beam parameters and characteristics of the turbulent atmosphere. Quantitative and qualitative differences are discovered between the studied coherence characteristics of the Bessel-Gaussian optical beam and the conic optical wave. Comparison of investigated characteristics of a coherence of pseudo-Bessel optical beams: a Bessel-Gaussian beam and a conic wave, with similar characteristics of diffraction-free Bessel optical beam is realized. In general, under identical propagation conditions in the turbulent atmosphere, the coherence of a conic optical wave is higher than the coherence of a Bessel optical beam.
Acoustic and electrical effects in the atmosphere surface layer due to some ionospheric sources
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We present experimental results of the study of acoustic gravity waves and electric field generation during auroras. Vertical component of electric field in the atmosphere surface layer and atmosphere pressure were recorded during the field study. Analysis of the obtained data shows that synchronous variations of the pressure and electric field strength appear with the development of auroras. It is seen that the amplitude of electric field perturbations is approximately proportional to the amplitude of variation in the pressure.
New approach to assessment of energy of sources of infrasound disturbances in atmosphere
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It describes new approach to assessment of energy sources of infrasound perturbations by spectrum of fluctuations in atmospheric pressure given stratigraphy of the atmosphere. It offers phenomenological model of spread of infrasound in standard atmosphere based on data of instrumental observations made during studying infrasound signals from powerful explosive atmospheric sources. There has been developed technique for assessment of energy which uses integral dependence of energy on power spectrum. Obtained results are consistent with known researches data.
Formation the texture features vector using the energy approach
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The application of cluster analysis in the problem of classification of data obtained from remote sensing of the Earth is considered. A method for searching for image local features using masks Laws, and the formation of a vector of texture features is considered.
Optoelectronic bistatic communication in the UV wavelength range
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Previous and new results obtained at the IAO SB RAS on problems of optical communication on scattered laser radiation in the UV wavelength range are discussed in the report. Examples of implementation of optical communication in field experiments at night and in the daytime are presented.
Comparative analysis of key parameters of "photonic nanojets" from axisymmetric nonspherical microparticles
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The effect of "photonic nanojet" (PNJ) arising in the near-field scattering region at the surface of dielectric axisymmetric microparticles (hemisphere, axicon, combined particles) under optical illumination is considered theoretically. Numerical calculations of PNJ key parameters (length, width, peak intensity) were performed using the method of discrete-dipole approximation; the dependence of jet’s key parameters on the geometric shape of the microparticles is analyzed. We show that using a special type of combined transparent particles consisting of an axicon and two attached hemispheres, ultra-localized light fluxes with a peak intensity considerably exceeding the corresponding values for particles of simple shapes (hemisphere, axicon) can be realized.
Variations of the echo signal of the pulsed coherent Doppler lidar in the turbulent atmosphere
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The paper presents the results of an experiment on the measurements of the echo power of a coherent lidar signal from a topographic target under various turbulent conditions in the atmosphere. The intensity of optical turbulence was controlled by acoustic weather stations that registered temperature fluctuations of air near the propagation path of a probing beam. It is found that at moderate turbulence, the dynamics of the change in the recorded average power of the lidar signal echo coincides with the dynamics of the change in the intensity of optical turbulence in the atmosphere: an increase in the average power of the echo signal occurs simultaneously with an increase in the magnitude of the structure characteristic of the refractive index, and a decrease in the structure characteristic leads to a decrease in the signal ratio of the lidar noise.
Backscatter amplification effect of the mean normalized signal power of coherent lidar in the turbulent atmosphere
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It is presented the calculations of the mean normalized signal power of pulsed coherent Doppler lidar as a function of the intensity of optical turbulence on the propagation path of the probing beam. It is shown that with increasing the optical (refractive) turbulence in the atmosphere, the mean normalized signal power increases with respect to the mean power of the echo of the signal in the absence of turbulence and then decreases and becomes less than the mean normalized signal power in the absence of turbulence. The calculations had performed for the parameters of the Stream Line lidar system. Comparison was made the calculated data with the results of measurements of the mean normalized signal power of the Stream Line after scattering of the probing beam on a screen located at a distance of 500 meters from the lidar.
On the transformation of images of cloud field elements when observing them in the topocentric observer coordinate system
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In this paper we consider the transformation of the trajectory of cloud formations in the system of the topocentric observer with their linear character of motion at a fixed altitude around the planet's surface.
Algorithm for reconstruction of the Earth surface reflectance from Modis satellite measurements in a turbid atmosphere
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An algorithm for reconstructing the spectral reflectance of the Earth surface in the visible and near-IR spectral ranges is suggested that takes into account the factors that play a significant role under conditions of a highly turbid atmosphere. The conditions for the applicability of the algorithm are estimated, and a number of procedures accelerating the process of obtaining data with a controllable error are presented.
Distributions of the mean intensity of the laser beam during passage of the shock waves formed nose fairing ogival-shaped body, in turbulent atmosphere
A. A. Sukharev,
E. D. Zaloznaya
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In work on the basis of numerical simulation, the problem of propagation of a laser beam through a shock wave formed by a nose cone of an ogival-shaped form was solved. The results of an analysis of the average intensity, intensity fluctuations, and regular and random displacements of optical beams propagating through the region of increased density are presented. The results are obtained for traces of different geometry depending on the turbulent conditions of light propagation.
Variations of the height optical turbulence profiles at the Baikal Astrophysical Observatory and the features of its deformations in latitudinal direction
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The work discusses the optical turbulence structure and dynamics at the Baykal Astrophysical Observatory (BAO) site. The characteristics of the optical turbulence including Fried radius, isoplanatic angle are analyzed. Estimates of the variations of the height profiles of the air refraction index turbulent fluctuations at the Baykal Astrophysical Observatory are given. Using the mean height profile of the structure characteristic of the air refraction index turbulent fluctuations, diurnal variations of the Fried radius at the BAO site are estimated.
Observation of "subpargelium" over the ground source of light
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Observation of subpargelium from ground-based light sources at the panoramic-optical station "TomSky" of the IAO of the SB RAS.
Correction for thermal and turbulent distortions in a multichannel optical system
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In this paper the results of simulation are presented of multichannel radiation propagation in a turbulent atmosphere and under conditions of thermal blooming, and correction for nonlinear thermal distortion on the base of the beam phase control is considered. The results demonstrate dependence of correction effectiveness on number of channels and on precision of a reference beam phase reconstruction. Addition increase of effectiveness is possible with adjustment of amplification in the channels of the optical system, i.e., with the use of amplitude-phase control of radiation.
Statistical estimates of the transfer characteristics, limiting ranges, and information transfer rate by atmospheric optical non- line-of-sight communication channels
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The impulse response of non-line-of-sight atmospheric communication channels for the case of arbitrary position of the receiving system relative to the direction of the source has been simulated statistically. The approximated equation for estimation of the quality of a communication channel from the power of received radiation is proposed. For a particular case of the transceiving system, the limiting arrangement of the receiving system, at which communication is possible, and the limiting frequency of transmitted pulses are estimated.
Fluctuations of the eikonal of an extraordinary wave reflected from the inhomogeneous ionospheric plasma
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The statistical properties of the eikonal (phase path) of an extraordinary wave reflected from the plane layered magnetoactive ionospheric plasma containing random inhomogeneities of the electron density are considered. The ray trajectories are determined numerically for propagation at the magnetic equator. The spatial coefficients of the autocorrelation of the eikonal at various angles of the ray entrance into the ionosphere are found.
Estimation of regular refraction and simultaneous broadening of laser beam in the atmospheric boundary layer
S. L. Odintsov,
V. A. Gladkikh,
A. P. Kamardin,
et al.
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Possible refraction of laser beam simultaneous with the beam broadening due to turbulence in the atmospheric boundary layer is estimated. Experimental data obtained with an MTP-5 meteorological temperature profiler and a Volna-4M sodar are used for the estimation. The main purpose is to separate the cases, when the strong refraction and significant broadening of a laser beam took place simultaneously, and to analyze them.
Coherence radius of laser beam in the atmospheric boundary layer
S. L. Odintsov,
V. A. Gladkikh,
A. P. Kamardin,
et al.
Show abstract
Estimates of the radius of spatial coherence of the laser beam in the atmospheric boundary layer are reported. Experimental data obtained with a Volna-4M meteorological acoustic lidar (sodar) were used for the estimates. The main purpose was to draw the diurnal average profile of the coherence radius for different seasons at different levels.
Multipurpose television system of operational aid to navigation in coastal zone under low-visibility conditions
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In this work, we describe a prototype of television system of course setting (TSCS) in precision orientation of vessel moving along straight-line directions in accordance with video and acoustic information transferred via radio channel to receiving instrumentation. A key salient feature of TSCS is that the ship can be navigated within the line of sight at distances as long as 20 km at up to 1-m SD of cross-track deviation from preset course, and that observations are possible under the conditions of decreased atmospheric transparency. The components of receiver-indicator and inshore part of TSCS are listed. The main technical characteristics of instrumentation and TSCS capabilities are shown. Prospects of further development are indicated.
Behavior of the backscattering intensity enhancement factor of vortex laser beams propagated in a turbulent atmosphere and reflected from a diffuse target
D. S. Rytchkov
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The paper presents the results of a study of the backscattering enhancement of optical beams propagated on monostatic location paths in the turbulent atmosphere. The backscattering enhancement factor (BSE) behavior of vortex LaguerreGaussian beams was investigated in conditions of the weak turbulence fluctuations of light intensity. It is shown that, unlike light beams with a regular wave front, the dependence of BSE factor of the average intensity of the vortex beams on the optical turbulence intensity has a saturation level determined by the value of the topological charge and the radius of the diffuse target.
Simulation of polarized radiative transfer in the atmosphere with spatially inhomogeneous cloudiness using CUDA parallel programming technology
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The parallel Monte Carlo algorithms developed for numerical simulation of the polarized radiative transfer in the Earth’s atmosphere are discussed. The results of their testing in the aerosol atmosphere and cloud layer as well as the results of calculation of the Stokes vector in an environment with spatially inhomogeneous clouds are presented. Problems of improving the efficiency of the Monte Carlo simulation by transition from sequential CPU computations to parallel GPU computations are discussed. The acceleration rate of the radiation codes achieved by parallelizing computational algorithms on a graphics processor is given. It is shown that the changeover of computing from conventional PCs to the architecture of graphics processors gives remarkable increase in performance and fully reveals the capabilities of the technology used.
Features of the angle-selective photoinduced light scattering indicatrix formation in LiNbO3:Rh crystals
Vitaliy A. Maksimenko
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Photoinduced light scattering (PILS) in the doped lithium nuobate crystal arises when one is illuminated with coherent light. The experimental results of the angle-selective photoinduced light scattering investigation in LiNbO3:Rh crystals are presented. The calculation of the scattering spatial structure is given. Angle-selective scattering is considered as kind of the four-wave vector interaction. The paper presents results of the selective PILS experimental and theoretical investigation for case when pump beam is in the plane that perpendicular to optical axis of the crystal.
Detection of an optical vortex topological charge and coordinates
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The algorithm of an optical vortex coordinates and topological charge detection is considered. In the algorithm a vortex is localized as a point of an interference fringe branching. With application of the algorithm interference patterns obtained in laboratory and numerical experiments are analyzed and characteristics of vortices revealed in corresponding examples are presented.
Variations of natural electric potentials in Yakutsk and their communication with perturbations of the magnetic field
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A comparative analysis of the parameters of the components of the magnetic field and electrical potentials at the polygon of the IKFIA of the SB RAS near Yakutsk, far from industrial interference from the autumn of 2016 to the winter of 2018, is given. Seasonal variations of electric potentials are presented from 17.10.2017 to 07.02.2018. The variations of the Earth's magnetic field and electrical potentials during a large magnetic storm are compared on 07-09.09.2017. The correlation coefficient obtained is 0.5-0.9.
Determination of the coefficient of wind shift of bullets from disordered samples of hit points coordinates
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The results of a statistical analysis of the experimental data obtained during the polygon tests of a passive optical wind speed meter are presented. In the course of the tests, the possibility of using a measuring instrument for correcting for aiming to correct the wind shift of the bullet was evaluated. During the experiments, the arrays of the coordinates of the hit points and the values of the component of the wind speed integral to the line of sight were registered, but the one-toone correspondence of the elements of the arrays was not established. The report proposes a method for determining the coefficient of linear interrelation for similar arrays and compares the estimate of the wind shift coefficient of the bullet calculated from the experimental data with tabulated values.
A study of the spatial distribution of pulsation on discrete frequencies of the tones in the field of turbulent decay of supersonic jet of laser transillumination data
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The report presents the results of a study of the location of excitation areas of discrete of acoustic tones in axisymmetric supersonic jet in its turbulent breakup. Peak amplitudes of laser beam intensity spectra found at frequencies of discrete tones vary markedly both across the section of the jet, and with change the distance from the nozzle. This allows to trace the configuration of the jet area, where corresponding tones excitation arises. We presents the distribution of the screech excitation areas corresponding to different mechanisms of his arousal.
Cloud characteristics and cloud radiative effects according to COSMO mesoscale model and measurements
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We analyzed clouds macrophysics and their radiative effects according to COSMO mesoscale atmospheric model and measurements at Lindenberg Observatory (Germany). Different cloud parameters simulated by the model and derived from measurements of ground-based remote sounding systems as well as by measurements of the BSRN station have been compared for snow-free conditions during March-October, 2016. We show that simulated water vapor content (QV) values were higher than the observed ones in the middle and upper troposphere. Furthermore, the modeled cloud ice water content (QI) is significantly higher at these altitudes and the ice cloud water path (TQI) is ten times higher than the observed value. Typical values of TQI and of TQC (liquid cloud water path) lie within 3*10-13-1.1 kg/m2 and 0.0017-2.9 kg/m2 , respectively with average values of 0.015 and 0.079 kg/m2 correspondingly. We also found a positive bias with the measurements for the TQC greater than 0.1 kg/m2 and a negative bias for other values. A clear nonlinear dependence of solar irradiance at ground against TQC values was obtained both from measurements and model experiments. We showed a significant (29%) underestimation of model solar irradiance for the same TQC values in overcast cloud conditions compared with the observations.
The mean power amplification of backscatter radiation by plane mirror at the strong optical turbulence regime
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The results of numerical simulation of the laser radiation propagation reflected by a flat mirror on an atmospheric path under conditions of strong turbulent intensity fluctuations of the wave field have been presented. The ratio of the backscatter radiation mean power to the mean radiation power transmitted to a double distance have been analyzed. It has been shown, with an increase of the optical turbulence the mean backscattering power almost 1.5 times increase at a receiving aperture diameter of less than 5 cm in comparison with the mean power for direct propagation by the double distance.
Development of a model of atmospheric turbulence at Baikal Astrophysical Observatory site of the Large Solar Vacuum Telescope
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The Baikal Astrophysical Observatory of Institute Solar- Terrestrial Physics of Siberian Branch of Russian Academy Sciences is located at an altitude of about 700 meter above sea level on the shore of Lake Baikal, Russian Federation. Large Solar Vacuum Telescope (LSVT) is the main telescope of the Baikal Astrophysical Observatory. We develop models of vertical profile of atmospheric turbulence (the refractive-index structure constant) and wind speed at the BAO for adaptive optical system design of LSVT. We also presented vertical profile wind speed and the refractive-index structure constant is obtained from NCEP/NCAR Reanalysis base.
The echo signal level of a coherent Doppler lidar with allowance for scanning by a probing beam
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The influence of scanning by a probing beam on the echo signal level of a pulsed coherent Doppler lidar on an horizontal and oblique paths in the atmosphere has been studied numerically. It has been shown, when scanning by the probing beam is taken into account, the heterodyne efficiency decreases as the lidar sounding rang increases. The higher the angular scanning rate, the greater the mismatch of the wavefronts of a reference and probing beams, the lower the echo signal level.
Testing method of large-sized convex optical surfaces
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The present report is devoted to the method of large-sized convex optical surfaces testing. This method is based on socalled orthogonal ray scheme, where the convex testing surface is illuminated by a collimated beam, which is perpendicular to the optical axis of the surface. The interference pattern is produced by the interaction of the reference beam passing over the test surface and the object beam reflected from the test surface. The interference pattern contains the information about the tested surface shape. The main advantage of the proposed method is the absence of additional large-sized optical components. That is why the method is a perspective for extremely large mirror testing. The experimental setup, obtained inteferograms and a flat mirror reconstruction results are presented.
Nonresonance mechanisms of optical nonlinearity of aerosols
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The comparative analysis of the non-resonance mechanisms of cubic optical nonlinearity in aerosols was carried out. The analysis includes the thermal nonlinearity (thermal expansion of the materials) and the concentration nonlinearities caused by electrostriction and thermodiffusion effects as well as the reorientational cubic response. It is showed that the greatest values of nonlinear coefficient are provided by thermodiffusion and electrostrictive mechanisms of concentration nonlinearity. The results are relevant for nonlinear optics of aerosols, as well as optical diagnostics of such media.
Dufour effect in the nanosuspension in a light field
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It were analyzed the Dufour effect in the transparent nanosuspension in a light field. The space non-uniform light field generates the nanoparticles flow due to electrostrictive gradient forces. The concentration flow generates the thermal flow due to the Dufour effect and therefore the thermodiffusion (Soret effect). The dynamic holography method is proposed for the investigation of those phenomena. The Dufour thermal response and the thermodiffusion phenomenon both change the magnitude and relaxation time of the electrostrictive hologram. The results are relevant to the optical diagnostics of the nanosuspensions and nanofluids.
Self-focusing of the radiation in a nanosuspension
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It was analyzed the self-focusing regime of the Gaussian beam in the nanosuspension with electrostrictive nonlinearity. The theoretical analysis of the light-induced mass transfer in the nanosuspension was carried out for large intensities of the Gaussian beam radiation, when the concentration change is comparable to the primary. The nonlinear lens in this mode is the exponential function of the incident light intensity. It is shown that the critical power value decreases significantly for high intensity beam. The results are relevant to the study of the radiation self-action in the nanosuspension and optical diagnostics of such materials.
Vertical distribution of wind speed at Baikal Astrophysical Observatory
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We study seasonal variations of the vertical distribution of wind speed at the Baikal Astrophysical Observatory (BAO) using NCEP/NCAR Reanalysis data base for development of adaptive optical system of Large Solar Vacuum Telescope (LSVT). The statistics of wind speed including mean and median profile, the first and third quartiles are calculated. Also we analyzed seasonal variations of wind speed on the pressure level 200-mbar, as parameter for estimation of suitable of the site for adaptive optics and level of atmospheric optical turbulence.
Dynamics of mid-IR light bullets
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We study numerically the change in characteristic sizes of light bullet’s (LB’s) high intensity region and the energy localized in it during filamentation of femtosecond mid-IR wave packet in LiF under the conditions of anomalous group velocity dispersion. It is found that in the process of LB’s propagation, the duration and diameter of a region with an intensity above 50 TW/cm2 , as well as the amount of energy contained in this region, vary with distance. General character of the process of light bullet’s formation in different dielectric media allows to extend obtained results to the transfer of high-density energy in atmosphere.
Effect of path length on the saturation level of radiation fluctuations of a narrow divergent laser beam in the surface atmosphere at snowfalls in non-point receiver
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Measurements of the radiation fluctuations of a narrow diverging laser beam on 260 (2x130), 520 (4×130), and 780 (6x130) m in the surface atmosphere in snowfalls are carried out. The wavelength is λ = 0.63 μm. The receiver was installed on the optical axis of the beam. The diameter of the receiver was 0.8, 3.1 and 25 mm. It is established that the fluctuations in the radiation of a laser beam increase with the volume scattering coefficient first, and then do not increase (saturate) and decrease (on a 780 m long path). The level of fluctuations and the saturation value increase with the length of the path at a maximum snowflake size of 1 −3 mm with a receiver diameter of 0.8 and 3.1 mm.
Stochastic simulation of peculiarities of laser pulse propagation in clouds and water media
Sergei M. Prigarin,
Daria E. Mironova
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In this paper, we describe results of Monte Carlo simulation of short laser pulses scattering in atmospheric clouds and water media. We analyze peculiarities of the photons distribution in thin cloud layers. The simulation results show that the secondary smaller luminous ring may appear for a short time in addition to the primary ring of light expanding in the cloud layer. The secondary ring appears because of local maxima of the cloud phase functions. Moreover, under certain conditions the effects similar to the expanding rings may be observed in water media.
Analysis of the polarization characteristics of the Schumann resonances from the data of long-term measurements in Tomsk
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The aim of the research is to analyze the variations in the positional angles of polarization ellipses of the extremely lowfrequency (ELF) electromagnetic (EM) background in the seasonally-daily cycle of observations. The statistical estimation of the positional angles of the polarization ellipses was carried out for the first three modes of the Schumann resonances taking into account the time of the day and the season of the year for the observation period from 2013 to 2017.
Estimation of local thunderstorms at the level of extremely low-frequency electromagnetic background in Tomsk
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The aim of the research is to analyze the contribution of close thunderstorms to the increase in the level of extremely low-frequency (ELF) electromagnetic (EM) background in the Siberian region. In this work, a technique for creating a response of close lightning discharges in magnetic induction components in the range up to 30 Hz is proposed and tested. The proposed method for joint analysis of synchronous monitoring data for local thunderstorm activity and variations of EM–focus is aimed at revealing the connection between the level of the EM background level and their parameters as the range and type of lightning discharge.
Attenuation of microwave radiation at millimeter waves in supercooled water of atmospheric aerosols
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The results of laboratory measurements of the attenuation coefficient of supercooled water, without scattering, at the frequencies from 140 to 180 GHz and in the temperature range from 0 to -45 °C are presented. The obtained values of the attenuation coefficient have been used to evaluate linear attenuation coefficient both in atmospheric water aerosols and in aerosols consisting of wet solid particles. In the examined range of frequencies, linear attenuation for the liquid water content of 0.1 g/m3 at the temperatures of -40…-45 °C is 1.2…1.5 dB/km.
On the Monte Carlo based algorithm for the estimation of bidirectional angular characteristics of polarized radiation
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This paper is focused on the Monte Carlo based projective algorithm for the estimation of bidirectional angular characteristics of polarized radiation, namely, radiation intensity and degree of polarization, transmitted through and reflected by optically thick layers of the scattering and absorbing media. We discuss two different approaches to the construction of the basic functions set for this method realization. We prove the identity of two considered projective expansions in the case of an axisymmetric type of the problem. Hemispherical harmonics, designed on the basis of associated shifted Jacobi polynomials, in comparison with those, designed as a factorization of modified Jacobi and Legendre polynomials are considered.
Monte-Carlo algorithms for defining the components of the aerosol scattering matrix
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The variations of the sky brightness are defined mainly by the volatility of the aerosol part of the atmosphere, which possesses strong scattering ability. Theoretical study of the radiation transfer problems is impossible without knowing it’s optical parameters. In this paper the problem of reconstructing the aerosol scattering matrix by using observations of polarized radiation in the solar almucantar, i.e., in various directions that make the same angle with the zenith as the line of sight to the Sun, is considered. Several iterative algorithms for estimation of the scattering indicatrix are constructed in Refs. 1–5. In these algorithms the indicatrix is successively refining by mathematical modeling based on the information of the angle distribution of the radiation intensity on the underlying surface and under the assumption that the contribution of the single-scattered radiation is rather large. In this work the predictor-corrector modification of the method is suggested, it allows to find more precise approximation of the scattering indicatrix and of two other scattering matrix elements responsible for the polarization of the radiation. In order to numerically substantiate the convergence of these methods, an algorithm of Jacobi matrices calculation for the iteration operators of the methods was developed, and calculations were carried out for various parameters of the atmosphere. Also a study of the influence of measurement errors on the reconstruction of the scattering matrix was carried out. Test calculations showed the stability of algorithms to errors in the initial data.
Cloud droplet size distribution reconstruction by the phase function
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This paper deals with an ill-posed problem to determine a size distribution for water drops in a cloud from a given scattering phase function. Numerical experiments show that a numerical method based on non-negative least squares with additional requirements of smoothness can be used to solve the ill-posed problem.
Modeling of particle density in plasma filament formed by femtosecond laser pulse in air
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The temporal evolution of intensity of N2 337 nm and N2+ 391.2 nm lines is compared with modeling results for filament plasma produced by tightly focused femtosecond laser pulse (0.9 mJ, 48 fs). Model correctly predicts enhanced emission of 1+ system, higher intensity of O I 777.4 nm line and dynamics of excited states density.
Effective algorithms of statistical simulation with additional branching for solving the problems of the theory of radiation transfer
Ilia N. Medvedev
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Weighted Monte Carlo algorithms for estimation of linear functionals of set of solutions of 2nd kind integral equations and systems of the 2nd kind integral equations are studied. A universal modifications of the weight collision estimator with branching of the chain trajectory relative to the elements of scalar or matrix weight are constructed. It is proved that the computational cost of the constructed algorithms is finite in the case when the basic functionals are bounded. The results of numerical calculations are presented for the case of use of a modified weight estimator for some problems of the radiation transfer theory with allowance for polarization.
The interannual variability of suspended matter concentration in the North-Western part of the Black Sea
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The purpose of this study is to investigate the interannual variability of the Black Sea suspended matter concentrations based on satellite data. The spatial and temporal variability of the bio-optical parameters are investigated by satellite data analysis. To analyze the interannual variability of suspended matter concentration on the northwestern shelf of the Black Sea, the combined monthly fields of the backscatter factor (BBP) for the period 1998-2010, obtained from the data of the SeaWiFS scanners, MODIS, MERIS are presented in a uniform spatial resolution grid of 4.6 km. empiric orthogonal function (EOF) analysis is applied to these data arrays with the aim to classify the spatial variability of BBP signal. As a result, the characteristics of the interannual spatial-temporal variability of the suspended matter concentration are given by four Empiric orthogonal function maps. They describe around 52% of summary suspended matter variance on the northwestern shelf of the Black Sea and thus its define the main regions (sources) of matter input. The influence of the Danube water inflow and suspended matters transport on the northwestern part of the Black Sea are discussed. The relationship between interannual variability of the suspended matter concentrations and large-scale atmospheric circulation processes was compared via North Atlantic Oscillation index.
The turbulence formation in the observatories of the South Siberia and the North Caucasus
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The astroclimate characteristics and the turbulence structure have been researched in Russian astronomical observatories: Sayan Solar observatory (ISTF SB RAS), Baikal Astrophysical observatory (ISTF SB RAS), Special Astrophysical observatory (RAS) and Center of Atmospheric Laser Sensing (V.E. Zuev Institute of Atmospheric Optics of SB RAS). The experimental results have been reached from the long-term series of astroclimate observations (2006–2017) with the mobile ultrasonic weather stations; theoretical results have been reached by numerical solving of the boundary value problems for Navier–Stokes equations. The domains of coherent turbulence over the observatories territories have been revealed. The causes of such domains are the terrain relief and the uneven heating of underlying surface. Large vortex coherent structures and the coherent turbulence have been registered inside the dome rooms. Numerical simulation allows to analyze the influence of design features and temperature conditions of the telescope elements, as well as the testing of the telescope optical characteristics, including minimizing the influence of external and dome room turbulence.
Criteria for selection of laser wavelengths for remote analysis of gas media
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The criteria for choosing optimal wavelengths for remote sensing of gaseous media are considered on an example of CO2 laser. The influence of various factors on the experimental and theoretical values of the spectral characteristics of the medium is estimated.
Dispersion of surface plasmon-polaritons in active planar structures of metal nanocomposites
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The paper presents the results of numerical simulation of the dispersion properties of surface plasmon-polaritons at the interface between an active composite medium based on metallic nanoparticles and a substrate of the same metals in the visible wavelength range. It is shown that the amplification and dispersion properties of surface plasmon polaritons in these structures can be varied within wide limits by varying the concentration of nanoparticles.
Influence of concentration and heating of gold, platinum, and silver nanoparticles on the thresholds of non-resonant generation in heterogeneous planar active media
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It has been experimentally shown that the thresholds of non-resonator laser generation in heterogeneous planar active media in solutions with nanoparticles of gold, platinum and silver practically coincide. The excess energy obtained by plasmon resonance does not affect the lowering of laser generation thresholds but is spent on heating the nanoparticles.
Results of numerical testing of algorithms for centering of focal spots in a Shack-Hartmann wave front sensor
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The weighted centers of gravity algorithm calculate the centroids coordinates of the Shack-Hartmann patterns which are recorded by the Shack-Hartmann wave front sensor in the process of adaptive correction of turbulent distortions of laser radiation. It is believed that the algorithm of weighted centers of gravity gives an optimal result regardless of the signalto-noise ratio for point sources. In addition to the algorithm for weighted centers of gravity of focal spots, there are other algorithms for centering the image in the plane of the receiving device. Here, based on numerical experiments, we give an estimate of the weighting and quadrant algorithms for centering the focal spots of the registered Shack-Hartmann pattern.
Reconstruction of the wave front and measurement of the speed of cross-wind transport of turbulent distortions of optical radiation by not fully defined Shack-Hartmann pattern
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The Shaсk-Hartmann wave front sensor measures the coordinates of the energy centers of gravity of the focal spots located in the plane of the receiving device in the form of the Shack-Hartmann pattern. The Shack-Hartmann pattern can be definite and not fully defined, i.e. on it there can be no separate focal stains or groups of focal spots. The information extracted from such Shack-Hartmann patterns change significantly the result of the wave front reconstruction. This suggests also the creation of a modification of the previously developed correlation algorithm for calculating the speed of transverse wind transfer of the turbulence. The results of numerical studies are presented.
Measurement of wavefront by sensors of Hartmann type with multilens rasters
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The wave front sensor of the Hartmann type wave front sensor consists of two parts: optical and algorithmic. The parameters of the elements of the optical part of the sensor can vary. The results of the analysis of the efficiency of the sensor measurements are presented depending on the size of the lens raster. The analysis is performed on numerical models of the propagation of laser radiation in a randomly inhomogeneous medium, of the atmospheric turbulence, and of the Shack-Hartmann wave front sensor.
Measuring methods of arrival angles of the laser radiation in the system of adaptive optics
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To calculate the control signals of a piezoceramic deflector when measuring the angles of arrival of optical radiation transmitted through atmospheric turbulence, various methods for estimating the beam image in the focal plane of the recording device can be used. The results of numerical studies of the accuracy of calculating the energy center of gravity of an image in the focal plane in several different ways are presented. These methods are used both in split photodetectors and in the Shaсk-Hartmann wavefront sensors.
Testing of the algorithm for correction of satellite images of the Earth’s surface in the visible and near IR ranges with allowance for polarization
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An algorithm for atmospheric correction of satellite images in the visible and near IR ranges with allowance for polarization of radiation is proposed. Its accuracy is estimated in comparison with the NASA MOD09 algorithms with southern area of the Tomsk Region taken as an example.
Deflector for correction of tilts angles of wave front
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An optical deflector designed to stabilize the position of the image at the input aperture of the optical system has been developed. The deflector contains an electronic control unit that operates with digital and analog input signals and an actuator based on piezoceramic actuators and a flat mirror. Special design solutions of the actuator ensure that the flatness of the mirror remains in the entire range of correction angles, and the electronic damping system suppresses the vibration of the mirror under a pulsed control signal. Adaptive optics systems with the described deflector are applicable in astronomical telescopes, in ground-based video surveillance and laser scanning systems.
Completely conservative numerical scheme for the nonlinear Schrödinger equation
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The fulfillment of the conditions for the complete conservatism of various numerical schemes that are most widely used in the numerical study of the nonlinear Schrödinger equation(NLSE) in the filamentation problem is analyzed, that the use of standard procedures for the numerical realization of NLSE with higher nonlinearities leads to a significant violation of the law of conservation of the Hamilton function in the filamentation process. The solution of this problem is proposed.
Influence of the phase front of the fs-pulse on the characteristics of the multiple filamentation
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The goal of the work was the experimental study of femtosecond filamentation laser pulses using a bimorph deformable mirror (DM). Phase distortions of different parts of the laser beam make it possible to control the position of the filamentation domain along the entire length of the model path. The use of a bimorph deformable mirror makes it possible to determine the localization of filaments and high-intensity channels in the cross-section of the beam. The mode of formation of long (> 100 m) high-intensity (1011-1012 W/cm2 ) weakly converging non-filamentary channels was detected.
The emission spectra in a femtosecond plasma of aerosols
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The report presents the results of experiments on plasma inducing on aerosol particles containing metals placed in the filamentation area of the beam and identification of the elemental composition from the emission spectra.
Using the Shack-Hartmann sensor for imitation of thermal aberrations and controlling the operation of an adaptive system
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The results of an experiment using the Shack-Hartmann sensor to control aberrations inside an adaptive transmissive optical system are presented in this article. The correction was made using the signal of reverse atmospheric scattering with different parameters of the transceiver. It is shown that with the optimal parameters of the receiving transmitter, the level of artificially introduced spherical aberrations is reduced by 10-15 times.
The transport equation in a turbulent weakly nonlinear medium and the methods numerical solution
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An equation is formulated for the Wigner function of the light field from the nonlinear Schrdinger equation in the weak nonlinearity approximation of the transfer equation type. Various numerical approaches used to solve this equation for the Wigner function are analyzed.
Adaptive stabilization and imaging system on the Baikal Large Solar Vacuum telescope
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The results of experimental studies of the effect of atmospheric turbulence in the adaptive optical image correction system at the Baikal Large Solar Vacuum Telescope (LSVT) are presented. To eliminate the jitter and stabilize the image on the receiver, the appropriate hardware and software system that corrects the tilts of incoming wave front with frequencies up to 1 kHz has been developed in the Laboratory of the Coherent Adaptive Optics (LCAO). To obtain digital images of high resolution, the tip-tilt adaptive system is combined with a post-detection computer processing of frames using fast 2D parallel real time algorithms. Experimental data confirm the high efficiency of the dual adaptive system for stabilizing and forming images on the LSVT.
Chaos and order of the wave beams positional parameters at the output of long atmospheric path
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Statistical and nonlinear dynamic properties of the vector components and spatial moments tensors for the intensity distribution profile of wave beam at the output of an atmospheric path are considered. As a reference parameter characterizing the state of the atmospheric path Rytov parameter was chosen. The ambiguity of the relation between the Rytov parameter and the dispersion characteristics of positional parameters for a collimated beam is proved experimentally.The methods allowing to select the number and type of regressors for predicting the beam profile variations at the temporal microscales are discussed.
Cohen class time-frequency mapping in the analysis of the non-stationary parameters of a wave gaussian beam at the atmospheric path output
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The experimental results of the time-frequency maps structure research are presented. The maps were received on the basis of Cohen class square mapping, particularly, using Wigner-Ville pseudo-distribution. Quasi synchronous monitoring of the atmospheric channel conditions and of a beam intensity spatial distribution is realized by means of the high-speed cameras of computer vision. The cameras record dynamics of a profile intensity distribution of a single-mode collimated signal beam at the receiving plane and that of the reflected sounding multimode beam. At an input of the long distance atmospheric path there comes the generalized Gaussian signal beam with the defined Rayleigh length and wavefront curvature. At the path output the spatial moments of the beam from the zero to the fourth orders are registered. The spatial moments allow to describe in details beam distortions along the propagation path with the temporary resolution not less than 1 ms.
Angular displacements of laser beams propagating through a flooded supersonic jet
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The paper presents the results of experimental studies that investigated the fluctuations in angular displacements of laser beams propagating through a flooded supersonic jet on an aerodynamic tunnel VJU ITAM SB RAS. The angular displacements were measured with a coordinate photodiode, which was placed in the distance of 1 m of the receiving diaphragm. The flooded jet ran vertically upwards with the npr=5. The mean and the temporal frequency ranges of the fluctuations in the wavefront direction, as well as the dependency of the intersection area of the supersonic jet are studied
"The first light" for the system of inputting the elements of AO into the optical path of LSVT
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This paper describes the features of the two-mirror adaptive system for correcting atmospheric disturbances of the Large Solar Vacuum Telescope, developed with allowance for the correction of instrumental vibrations of telescopes in a wide amplitude-frequency range with an open siderostat supply mirror. Correction of the general slopes of the light wave front and its deformations is carried out separately. The adaptive optical system is designed to work with extended light sources (the Sun), which have a low contrast of image details.
Estimation of the crosswind along surface paths from a video sequence of distant objects: comparison with contact measurements
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Possibilities a passive method developed for estimation of the crosswind velocity from a video sequence of incoherent images along 1 km observation paths are analyzed. The method results are compared with anemometer measurements.
Verification of the passive optical meter of crosswind and turbulence in atmospheric experiments
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The modified prototype of crosswind velocity and atmospheric turbulence passive optical meter was tested in long-term field experiments. The obtained results are compared with the measuring data by independent acoustic, lidar and active optical methods.
Distribution of field amplitude fluctuations at the larger than unit relative variance of intensity fluctuations
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The distribution laws of fluctuations of the field amplitude and intensity of laser beams propagating through the atmosphere are studied based on numerical simulation. The calculations are performed for the beams having the orbital angular momentum (vortex beams) at different points of their cross section. The transformation of probability densities of fluctuations of the field amplitude and intensity of the beams is studied for the relative variance of intensity fluctuations (scintillation index) varying from unity to three. It is shown that if the scintillation index has the same values at different points of the beam, the probability density of intensity has the same form, whereas the probability density of the real and imaginary parts of the field amplitude can differ.
Optimization of the lidar parameters for atmospheric turbulence study
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The turbulent lidar is a micro pulse dual-channel aerosol laser locator, operating on the backscattering enhancement effect (BSE). This effect forms a peak on the axis of the laser beam, therefore, when the intensity of atmospheric turbulence changes in one of the receiving channels of the lidar, a proportional change in the echo signal occurs. The second channel is necessary for normalization of the first one in order to exclude the influence of transmitter power fluctuations and scattering properties of the atmosphere along the direction of sounding. The sensitivity of lidar is largely determined by its design. The experimental and theoretical data were analyzed characterizing the peak of backscatter enhancement. A scheme of a lidar transceiver with spacing between receiving channels is considered and parameters of the optimal lidar design are determined. Calculations have shown that the optimal diameter of the transmitting-receiving aperture should be 70 mm.
Lidar "BSE-4" for the atmospheric turbulence measurements
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The task was to create a compact turbulent lidar, working on the backscatter enhancement effect. Initially, it was planned to make a lidar with the spacing of the receiving channels using two small 50 mm Mersenne telescopes collected from off-axis parabolic mirrors. Despite the measures taken, the system did not pass the stability test for prolonged operation. Then we used an optical layout in which the receiving channels were combined. The converted device turned out to be workable, but its sensitivity was slightly lower than that of the channel spacing scheme. Lidar “BSE-4” was successfully used in field experiments in 2017 (Tomsk, Lake Baikal).
Software for phase functions fast computation and optical phenomena visualization in water-drop atmospheric clouds
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In this paper, we describe numerical and visualization software that allows one to compute phase functions of atmospheric water-drop clouds for an arbitrary distribution of drop radius and represent such optical phenomena as fogbows, glories and coronas. High performance and computational accuracy of the algorithms are provided by the use of a large array of data preliminarily calculated for monodisperse media, and numerical integration by high-order quadrature rules. The software has a user-friendly interface, which allows an interactive design of particle size distributions, simultaneous computation of phase functions for several wavelengths, and immediate visualization of possible optical phenomena.
Reduction of data processing error of heterogeneous system laser sensing
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Modern research devices allow obtaining a large amount of information in remote laser sensing of atmospheric aerosols. However, the increase in the data volume processed by the Fredholm integral equation of the first kind increases the processing time non-linearly. The paper describes a method using known algorithms for integral equation processing with the data of aerosols laser sensing. The use of several samples from the transmission spectrum at more than 1000 wavelengths makes it possible to determine the dispersed particles sizes in a short time with an acceptable error. The developed algorithm is approved for determining the granulometric composition of laboratory heterogeneous systems. The results of laser diagnostics and the particle sizes determined from the electron microscope images were compared.
Correlation of the laser intensity fluctuations for two linked FSO communication systems
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Statistical parameters of laser beams counter propagating in the atmosphere are analyzed on the basis of numerical simulation, as well as a possibility of implementing the reciprocity principle of the counter propagation of optical waves from point sources with the aim of cryptographic keying with the help of finite-size receiving-transmitting apertures. The dependences of the degree of correlation of signals from coupled wireless optical communication laser systems on the distance and aperture sizes are studied. The quantitative dependence of the aperture size on the space between the laser systems is derived with the aim of maintaining the correlation degree at a level above 0.9999.
Random wandering of Airy axisymmetric laser beam propagating through the turbulent atmosphere
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The efficiency of using an Airy axisymmetric beam for energy transfer and concentration to a given point in a randomly inhomogeneous medium is studied. Capabilities of this beam are assessed in comparison with beams of other types. The variance of beam wandering is calculated. For the given parameters of the transmitting system, path length, and degree of turbulent distortions, the intensity at the axis of the considered Airy beam is shown to be much lower than that of other beams, the Airy beam is compared with. In addition, the Airy beam is characterized by smaller wandering.
Digital holography in hydrobiological research
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In paper the device – set of hardware and software for non-contact investigation of marine particles is presented. The device is designed on digital holography principles. Hardware features of submersible holocamera (or DHC sensor) are considered. Methods are described for the processing of holograms and retrieve information. Results of approbation of the device are presented.
Evaluation of the possibility of using remote methods for the classification of water sources for specific electrical conductivity
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The possibility of monitoring of thermokarst lake water volume of arctic and subarctic regions by remote sensing radiophysical methods is considered. The purpose of monitoring is to control global changes in the Earth's climate. Samples of natural water from water sources of the Tomsk region and the Yamalo-Nenets autonomous region (test site is the village of Khanomyi) are studied. The measurements were carried out by a microwave instrument based on an irregular microstrip resonator and by a conductometer made according to the original scheme.
Optical Investigation Of Atmosphere And Ocean
Properties of aerosol and cloud from Raman-mie lidar and Radar soundings
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In this study, a multi-wavelength Raman-mie Lidar, and a 35 Ghz Radar are employed to measure the properties of aerosol and cloud. The extinction at 0.355μm and 0.532μm and backscattering at 0.355μm, 0.532μm and 1.064μm coefficients from lidar, and the effective reflectivity factor from radar are inversed for use. Furthermore, the quantities responsible for microphysics can be extracted and explained as the dimensionless values, such as the linear depolarization ratio, the color ratio, and the other ratios. Then these microphysical properties for aerosol and cloud during campaigns are analyzed for further use.
Influence of continents on spatial distribution of aerosol characteristics in the southern part of the World Ocean
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Based on multiyear studies in the Russian Antarctic Expeditions (51st-62nd RAE), we discuss the specific features of the spatial distribution of atmospheric aerosol characteristics (aerosol optical depth and aerosol and black carbon concentrations) in the southern part of the World Ocean. It is shown that, with the growing separation (up to 170- 350 km) from Africa in the southern direction, a general regularity is a factor of 1.3-4.2 decrease in the average aerosol characteristics. At higher latitudes (40-55°S), the aerosol characteristics saturate to a quasi-constant level, followed by a decrease in the average values toward Antarctic coasts.
Experimental prototype of mobile (airborne) lidar
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The "LOZA" small-size lidar is described. The lidar is intended for field measurements of the optical state of the troposphere, including situations of its arrangement onboard an aircraft-laboratory or a research vessel. The lidar carries out sounding of the atmosphere at two wavelengths of radiation from a solid-state laser of 1064 and 532 nm. Optical selection of lidar signals at these wavelengths is performed by two identical telescopes. In the visible channel, the signal is divided into two orthogonal polarized components, as well as a Raman signal at a wavelength of 607 nm is separated. The lidar signals are recorded by means of HAMAMATSU photomultipliers tube in analogue and photon-counting modes. In the IR channel, the signals at λ = 1064 nm are recorded by means of the C30956E-TC avalanche photodiode designed by Perkin Elmer.
The estimation of optical radiation influence on human pulse waves
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The paper shows the quantitative estimation of the electromagnetic optical radiation influence on the functional state of a human organism by analyzing pulse signals. It has been established that under the influence of the color preferred by the test subject, in comparison with its initial values, the absolute value of the Power Coefficient rises; the variability of the Hilbert-Huang characteristics rises; the analysis of the heart rate indicates the improvement of the functional state of an organism. Under the influence of a rejected color, the characteristics of a pulse wave indicate a decline in the functional state of an organism.
Seasonal and interannual variations of aerosol characteristics in the Arctic settlement Barentsburg (Spitsbergen archipelago, 2011-2017)
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Based on data of 7-year (2011-2017) measurements in the Arctic settlement Barentsburg (Spitsbergen archipelago), we discuss the seasonal and interannual variations in aerosol characteristics: atmospheric aerosol optical depth and nearground concentrations of aerosol, absorbing substance (black carbon), ions, as well as gas-phase species. For certain aerosol characteristics (especially in 2011 and 2012) we noted an anthropogenic effect of settlement, i.e., dust, black carbon, and pollutants from heat and power plant.
Features of spatial distribution of aerosol characteristics over Arctic seas
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Based on data of seven expeditions, we considered the specific features of the spatial distribution of aerosol physicalchemical characteristics over Arctic seas in Russia. It is shown that the average aerosol and black carbon concentrations and aerosol optical depth of the atmosphere decrease by a factor of 2-2.5 in the direction from west to east. A more detailed analysis in the sectors of the Barents and Kara Seas revealed a tendency toward a decrease in aerosol characteristics in the northeast direction. We noted that the average ion concentrations in aerosol composition are close in value over the Barents and Kara Seas. Continental and maritime sources make nearly identical contributions to ion composition of aerosol over these seas.
Chemical composition, microphysical and optical properties of aerosol in the atmosphere of the arid territories of Mongolia
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The paper discusses the results of experimental studies of chemical, microphysical and optical properties of atmospheric aerosol in different natural and climatic conditions of Mongolia. The main factor in the formation of the component composition of aerosols are anthropogenic emissions, whose proportion in the urban atmosphere (Ulan-Bator, Sukhbaatar) is significantly higher than at stations in arid regions where regional sources of emissions are associated with mining enterprises, road transport and terrigenous dust. The data of long-term observations AERONET at the station Dalanzadgad were used for analyze of the seasonal, annual variations of AOD in the Gobi Desert. It is established that high transparency of the atmosphere is observed (τ0.5=0.09) with a maximum in spring and summer (τ0.5=0.15) and a minimum in winter (τ0.5=0.04).
Average aerosol characteristics in three sectors of the Southern Ocean and the effect of Antarctic islands
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Data of measurements in Russian Antarctic expeditions (51st-62nd RAE) are used to analyze the specific features of the spatial distribution of the atmospheric aerosol optical depth, concentrations of aerosol and absorbing substance (black carbon) in the southern part of the World Ocean. We found no statistically significant differences in the average aerosol characteristics between three sectors of the Southern Ocean. Near Antarctic islands, we revealed the specific features in the spatial variations of aerosol characteristics: when the separation distance from islands increases to 250 km, the particle concentrations become two times larger, and black carbon concentrations become 26% smaller, primarily because of the redistribution between contributions of island (local) and maritime sources of aerosol, differing by the concentrations of aerosol and content of absorbing substance in it.
Experimental study of fluorescence spectra of oil pollutions on the terrain surface excited at 355 nm
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Laser induced fluorescence spectra of different types of petroleum products on various types of soils as well as natural and anthropogenic objects of underlying surface were measured for 355 nm excitation wavelength. Experimental setup was described. Results of fluorescence spectra processing were obtained. It was outlined, that fluorescence intensity of oil pollutions could have same value as fluorescence intensity of natural objects on underlying surface.
Lidar technique for the simultaneous determination of meteorological and optical parameters of the atmosphere using the vibrational-rotational and pure rotational Raman spectra
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The report presents a project of a lidar for the simultaneous measurements of the vertical profiles of the atmospheric temperature, humidity, and aerosol extinction using Raman effect. The Raman-lidar design based on the application of a powerful UV-laser in combination with the specialized diffraction polychromators using optical-fibers for the lidar signals transmission allows providing minimal dimensions and high reliability of the lidar.
Raman lidar for measuring the temperature of the stratosphere
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The article deals with the problem of developing a technique and creating equipment for regular observations of stationary variations in the vertical distribution of the stratosphere temperature. As a methodical basis, it is proposed to use a method for measuring the temperature of the atmosphere from the ratio of intensities of the sections of the purely rotational spectrum of spontaneous Raman scattering on nitrogen and oxygen molecules. A block diagram of a lidar based on the use of a single diffraction polychromator in combination with the transmission of optical signals by optical fibers is given. An experimental estimation of the total quantum efficiency of the photon counting system is carried out. The obtained data made it possible to clarify the technical parameters of the lidar and to increase the reliability of the estimate.
Software for numerical simulation of multicomponent gas analysis of the atmosphere
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A software system is presented developed for the complex numerical simulation of multicomponent gas analysis of the atmosphere in the infrared spectral region on the basis of combination of the differential absorption technique and differential optical absorption spectroscopy.
Seasonal variation of the diurnal behavior of aureole scattering phase function at the aerosol monitoring station of LOA IAO SB RAS
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In this article, the results of monitoring of an aerosol in a near ground layer of the atmosphere of the suburb of Tomsk are discussed. The submitted data are obtained by means of a closed volume aureole photometer allowing to measure round the clock an aureole scattering phase function in range of angles 1.2 - 20 degrees on the wavelength of 650 nanometers. The analysis and estimation of the difference in the mean monthly diurnal values in 2010-2017 carried out.
Evaluation of emissions of atmospheric trace gases from remote sensing and local observations at the St. Petersburg site: anthropogenic emissions and wildfires
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Emissions values, as well as emission ratios for greenhouse and reactive gases were evaluated for anthropogenic sources and wildfires. Our study is based on ground-based Fourier transform infrared measurements of CO, HCN, C2H6, H2CO, OCS and CH4 total columns, zenith-sky DOAS measurements of tropospheric column of NO2 and results of the local monitoring of CH4, CO2 and CO concentrations performed at the St. Petersburg site during 2013-2016. In addition, we involve into analysis the following data and information: satellite observations of the tropospheric column of NO2 (OMI), aerosol optical thickness (MODIS) and ultraviolet aerosol index (OMI, OMPS); information on location and intensity of wildfires; AERONET data on aerosol optical thickness; results of trajectory and dispersion simulations using HYSPLIT model.
Vertical light attenuation in the northwestern shelf of the Black Sea in the spring period: direct measurements, modeling, and satellite data
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In the paper a joint analysis of direct measurements of the seawater vertical diffuse attenuation coefficient with a satellite product was carried out for several stations on the northwestern shelf of the Black Sea in late April and early May 2017. An attempt to model the empirical spectrum of the seawater vertical diffuse attenuation revealed a number features of that were explained by the peculiarity of the vertical structure, namely, by the presence of an optically active layer, which is typical for the considered period of time and is associated with the thermocline formation process.
Seasonal variability and inter-annual anomalies of hydrooptical characteristics, chlorophyll "a" concentration, and temperature on the Black Sea surface in 2017
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On the basis of daily means of sea surface temperature, concentration of chlorophyll "a", diffuse attenuation coefficient Kd(490) and remote sensing reflectance Rrs(555) from the array of satellite measurements with high spatial resolution COPERNICUS spatial-temporal features of seasonal and inter-annual variability of these parameters on the Black Sea surface analyzed. Shown, that in 2017, the main maximums of the Chl-a concentration and the coefficients of diffuse attenuation Kd(490) were observed in November-December. The second maximum of Chl-a and Kd(490) in the northern coastal zone of the sea was observed from February to June, in the in the deep sea – from February to March, near the sea southern coasts – from February to April. The main maximum of remote sensing reflectance Rrs(555) was observed in June-July. Shown, that in 2017 the sea surface temperature was higher than the climatic norm, the largest anomalies were observed mainly on the northwestern shelf and in the zone of the Eastern large-scale cyclonic gyre. Anomalies of Chl-a and Kd(490) during the year were predominantly negative, and the appearance of positive anomalies was observed in April to the west and to the east from the Crimean coasts. The Rrs(555) values for almost the whole year were close to the climatic norm except for June, when they were several times higher than climatic values.
Lidar studies of the upper cloud boudary altitude
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Results of laser sensing of fluctuation of the upper cloud boundary altitude are presented in the report. A nonlinear relationship between the vertical and horizontal sizes of cloud inhomogeneities is established.
Monitoring of aerosol inhomogeneities parameters in atmosphere at 355 nm
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We present the results of experimental studies of aerosol inhomogeneities characteristics in atmosphere planetary boundary layer (PBL) at eye-safety 355 nm wavelength. For developed lidar system for monitoring aerosol inhomogeneities technical specifications of the key components are described. It includes a diode-pumped solid state (DPSS) laser with pulse energy 1.3 mJ, duration 7 ns and pulse repetition rate up to 500 Hz, Cassegrian telescope with prime mirror diameter 100 mm and photomultiplier tube (PMT) as photodetector. Lidar provides registration of aerosol elastic backscattering signal with high spatial (0.6 m) and temporal (0.002 s) resolution up to 1 km depending on atmosphere condition. The preprocessing algorithm to form lidar signal variation coefficient fields in "Range-Time" coordinates is discussed. Examples of these fields for different weather conditions are presented. Accumulated measurement data from 2015 to 2017 for spring-autumn period in Moscow region was analyzed and for more than 1 500 inhomogeneities shown histograms of size and average contrast. The obtained results are compared with the known measurement data in the visible spectral range.
A complex experiment of measuring the average power of lidar echoes in a turbulent atmosphere
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Data are presented about the variations in the average power of lidar echo signals with coherent and incoherent receiving over wide range of variations of the refractive turbulence strength in the atmosphere. It is established that in the case of incoherent receiving the backscatter amplification coefficient first increases with increase of the turbulence strength, then saturates at a certain level in the regime of strong turbulence on the probing path and decreases with further refractive turbulence strength increase. The maximum value of the amplification coefficient achievable at a given distance depends on the refractive turbulence strength at the moment of measurement. The time course of the backscattering amplification coefficient is in a good agreement with the temporal changes of the structural constant of turbulent fluctuations of the air refractive index, determined from independent measurements.
The ratio of submicrometer and coarse particles in the aerosol size distribution under smoke and background conditions
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Variability of the multi-year average ratio of number concentrations of submicrometer and coarse particles and their volume size distributions under smoke and background conditions are studied on the basis of monthly average data obtained at the Aerosol station of IAO SB RAS in 2000-2017. The data arrays on the disperse composition of particles are formed by means of the technique developed earlier, which provides for selection of the atmospheric aerosol realization using the P-criterion providing isolation of smoke and background situations on the correlation diagram of the soot fraction of submicrometer particles and the aerosol scattering coefficient.
Complex optical experiment with use of remote and local control of atmospheric parameters
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A description of a complex optical experiment using remote and local monitoring tools for studying the physical processes of formation of aerosol fields of the atmospheric boundary layer is presented. Examples of lidar-sudar studies of the structure of aerosol fields under conditions of pronounced convection are shown, as well as with stable stratification of the boundary layer. The results of studies of the structure of aerosol fields of the boundary layer of the atmosphere from the data of aerosol and Doppler lidars during the passage of atmospheric fronts are presented.
Thermally induced polarization distortions of contrast ratio for strobing the lidar signal by an electro-optical shutter
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This paper reports on an experimental study which was carried out to evaluate the performance of thermally induced polarization distortions of the contrast ratio of an electro-optical shutter. Thermal stabilization of electro-optic crystals in shutter is used for reducing thermo-optic effects influents for contrast ratio for strobing the lidar signal.
Laser reflection method applicability for vegetation monitoring at eye-safe sensing wavelengths
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We investigate the possibilities to use a laser reflection method for vegetation monitoring at eye-safe sensing wavelengths. A mathematical simulation involving spectral libraries of the vegetation reflection coefficients shows that the laser method (at the eye-safe sensing wavelengths in the ultra-violet and the near infrared spectral bands) can be accepted as a basis for vegetation monitoring. Laser sensing at the wavelengths of 2 and 0.38 μm or of 2 and 0.355 μm allows us to detect vegetation under adverse conditions with a probability of correct detection close to one and a probability of false alarm ~ second decimal places.
Atmosphere halogen oxides concentration retrieving by differential optical spectroscopy in the UV region of the spectrum
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The method of differential optical absorption spectroscopy is an effective tool for open-path measurements of atmospheric gases and impurities. The gas analyzers based on this method traditionally include a high pressure xenon lamp as the radiation source, that require high voltage, which makes gas analyzers are bulky and power-inefficient. Recent developments in fiber-coupling telescope technology and the availability of ultraviolet light emitting diodes have now allowed us to construct a portable, long path gas analyzer. The gas analyzer comprises two UV-LEDs emitting in the near UV-region of the spectrum, the system of optical fibers, a receiving-transmitting telescope, and spectrometer and treatment system. There are presents a description of the methodology and results of the measurement of chlorine and bromine oxides with gas analyzer based on UV-LEDs.
Influence of the optically active layer on the standard satellite product – diffuse light attenuation coefficient: simulation
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Based on numerical experiments in which the influence of the depth of the optically active layer on the spectral properties of the water-leaving radiances was studied, estimates for the accuracy of the reconstructed diffuse attenuation index using the standard NASA technique were obtained.
Multiyear research of atmospheric deposition: case study at the Listvyanka monitoring station (Southern Pribaikalye, Russia)
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Results of air surface aerosol and precipitation ion content studies done at the Listvyanka Station (Southern Pribaikalye) during 2000-2015 are discussed. The studies were performed by Limnological Institute, Siberian Branch of the Russian Academy of Sciences (Irkutsk, Russia) in continuous monitoring mode. Peculiarities of seasonal and interannual variability of aerosol and precipitation ion content are analyzed. A reduction of aerosol ion concentrations is observed since 2000 to 2015, while no such reduction of ion concentrations is seen in precipitation. The mean annual pH value and nitrate content show a tendency to decrease with simultaneous growth of sulfate and ammonium concentrations. Aerosol ion content changed in 2010-2015 as compared to the 1990’s. The change of aerosol and precipitation ion content is induced by climate change (warming, growing rain and snowfall) in the Baikal Region as well as by shift of heat and power plants emission components towards reduction of ash fraction and increase of acidulous gases.
Variations of temperature regime of the atmospheric boundary layer in regions with various orography
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The spatiotemporal variability of temperature in the atmospheric boundary layer has been studied comparatively in the city of Tomsk (Russia) and in the coastal zones of Lake Baikal (Russia) and Lake Issyk-Kul (Kirghizia). Measurements with the MTP-5 temperature profiler have demonstrated that in the summer season the conditions of thermal stratification of the lower 1-km atmospheric layer under urban conditions in the absence of large water reservoirs nearby and in the mountain areas on the coasts of big lakes differ widely. The types of stratification and parameters of the atmospheric boundary layer in the regions under study are determined.
Hydro-optical structure of the Black Sea active water layer in the spring-summer period of 2017
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The results of hydro-optical investigations performed in the spring-summer period of 2017 in the northern part of the Black Sea are considered. It is shown that during the spring survey (22.04.17 - 6.05.17), low concentrations of the total suspended matter were observed in the surface layer. The subsurface maximum in the vertical distributions of the total suspended matter concentrations was not present. In summer (14.06.17 - 4.07.17), due to intensive coccolithophore bloom, a higher content of suspended particles was observed. It was found that in summer the vertical structure of the total suspended matter concentration was characterized by a well-pronounced maximum at the depth close to the depth of vertical temperature and density gradients maxima.
Formation peculiarities of total suspended and dissolved organic matter fields structure in the northwestern part of the Black Sea according to data of hydrooptic observations
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Results of complex oceanographic investigations of northwestern part of the Black Sea in the early autumn period are presented. On the basis of hydrooptical characteristics' measurements the data on total suspended and dissolved organic matters spatial distribution, as well as Danube and Dniester rivers' estuary zones thermohaline structure, was obtained. The factors that determine bio-optical characteristics' of aquatic environment distribution, taking into account the wind direction and currents system, are estimated.
Influence of the direction of sound propagation along vertical atmospheric paths on the acoustic signal characteristics
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The influence of the direction of sound propagation along vertical atmospheric paths on the characteristics of received acoustic signal is discussed. The process of propagation of monochromatic acoustic radiation from the source to the receiver was simulated by the Monte Carlo method taking into account acoustic radiation absorption, excess turbulent attenuation, and refraction for different models of the atmosphere depending on the sound frequency and propagation path length. Calculations were performed for radiation frequency changing in the range 1000-4000 Hz. Here we present results of statistical simulations for a frequency of 2000 Hz. The data of statistical simulations demonstrated that practically in all cases, the intensity of radiation propagating upward exceeded the intensity of radiation propagating downward. For the intensity of single scattering, the difference was in the range 5-35 %, and for multiple scattering, it changed in the range 5-100 %. The results obtained are in good agreement with the data of a tethered balloon experiment.
Dynamics of turbulence kinetic energy from minisodar measurements
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In the report, spatiotemporal dynamics of the turbulent kinetic energy (TKE) retrieved from minisodar measurements of three wind velocity components in the range 5-200 m during 6 days in autumn is investigated. The results obtained demonstrated that the TKE increased with altitude, which is in agreement with the available literature data. In the surface 50-100 m layer, it slightly increases with altitude. The diurnal variations of the vertical profiles of the TKE are analyzed. The presence of maxima and minima in the daily behavior of the TKE was detected that can be explained by the effect of meteorological conditions. The influence of the averaging time was also estimated.
Adjustment of the vertical distribution of gas content in the air on the outgoing radiation of the atmosphere
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In this paper an analysis of the atmospheric model represented as a homogeneous surface layer and another homogeneous layer 10 km is provided. Parameters of the layers are defined for the standard atmosphere, provided that the contribution of the outgoing radiation atmosphere in the studied spectral plots methane absorption lines 1240.980 -1241.020 cm-1, 1240.901 -1240.949 cm-1 equal to deposits in the outgoing radiation from the Earth all mixed layers and their components. A system of two equations is solved, relating their content in each of the homogeneous layers with a change in the power of the outgoing radiation for each spectral region.
Results of observations of meteorological parameters pulsations in the surface layer
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A series of experiments was conducted using a multi-parameter meter for turbulent micropulsations of wind speed, temperature, humidity, pressure and aerosol particle concentrations. In the process of automated measurements, the accumulation of data on the turbulent characteristics of various meteorological parameters in the surface layer of the atmosphere was carried out. Based on the obtained experimental information, the synchronous behavior of the statistical characteristics of the measured substances and their turbulent flows and some preliminary results of their complex processing and analysis are considered.
Formation peculiarities of natural and pollutant substances’ fields structure in Balaklava bay (Sevastopol) according to hydrooptic observations data
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Results of complex Balaklava Bay waters' (the Black Sea) investigations received by using the multiparametric optical and biophysical complex "Kondor" are presented. Information on total suspended and dissolved organic matter fields' structure is received. A new method of dissolved oil products content determining is proposed, results of data comparing with the direct analytical method are presented, measuring error is estimated.
Comparison of atmospheric aerosol optical depths measured with different sun photometers in three regions of Spitsbergen Archipelago
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Results of multiyear (2011-2017) aerosol monitoring were used to compare the spectral aerosol optical depths (AOD) of the atmosphere, measured with different sun photometers at three Arctic stations on Spitsbergen Archipelago: Hornsund, Barentsburg, Ny-Ålesund. In addition to agreement of data in three regions, we also found that AOD in Barentsburg slightly (comparable to error) exceeds those from other stations located 110-120 km away. The AOD discrepancy is more pronounced in the shortwave part of the spectrum, indicating more abundant fine-mode aerosol in Barentsburg.
Estimate of methane-capacity of aerogel samples of different compositions
B. G. Ageev,
Yu. N. Ponomarev
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Results of gasometric measurements of the methane adsorption by aerogel samples of silicon dioxide SiO2 and hybrid aerogel SiO2/Al2O3 are presented together with estimates of the adsorbed gas concentration.
Interannual variability of average effective aerosol concentration fields in the Far Eastern region
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Results of simulation of effective quasi-two-dimensional average fields of volume concentration of submicron aerosol, obtained by the method of fluid-location of atmosphere (FLA) are discussed. The input information are AERONET photometric measurement data and back trajectories of the air parcels calculated by the HYSPLIT software.
Robust nonparametric estimations of the wind velocity functionals from minisodar measurements
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A method of robust nonparametric estimations of wind velocity functionals and their confidence intervals is suggested in the report that allows the estimations to be adapted depending on the initial functional distribution and outliers. It is shown that standard methods of data processing lead to considerable shift of location and low efficiency of the estimations in comparison with the nonparametric estimations of the weighed maximum likelihood method.
Appearance of the corner reflection effect in cirrus clouds for off-zenith lidar profiling
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The physical optics approximation is applied to calculate the backscattering Mueller matrix and the depolarization and color ratios for quasi-horizontally oriented hexagonal ice plates of cirrus clouds in the case of a tilted lidar. It is shown that the backscatter reveals some features caused by the corner reflection effect that is inherent to the pristine hexagonal ice plates. In particular, the backscatter creates sharp peaks of both the backscattering cross section and depolarization ratio at the lidar tilts of about 30 degrees off zenith. The experimental results obtained recently by Veselovskii et al. JQSRT, 2017;202:74–80 at the lidar tilt of 43 degrees have been interpreted as a partial manifestation of the corner reflection effect.
Investigations of the crystalline particle orientation in high-level clouds with a scanning lidar
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Scanning lidar LOSA-M3 makes it possible to measure the polarization characteristics of backscattering signals from aerosol and clouds at wavelength 532 and 1064 nm. The lidar transceiver is placed on a scanning column, which allows to change the direction of sounding within the upper hemisphere at a speed of 1 degree per second. The polarization characteristics of the transmitter (linear or circular polarization) can be changed by rotating the phase plates synchronously with the laser pulses. Conical scanning of the lidar allows identifying cloud areas with preferential zenith or azimuthal orientation of the crystal particles. The article presents the results of observations of the cloud polarization structure carried out in Tomsk.
Study of aerosol in near-surface layer of the marine and coastal atmosphere by the methods of microphysical and optical measurements, analysis, and simulation
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MaexPro model of aerosol of near-surface layer of the marine and coastal atmosphere is presented, which is based on long-term observations of particle distribution in the size range 0.01-100 μm. A key feature of the model is that the amplitudes and widths of aerosol modes of the particle size distribution functions (PSDF) are simulated as functions of fetch (X) and wind speed (U). The shape of PSDF and its dependence on the altitude above sea level (H) and relative humidity (RH) are studied. A formula is derived for the altitude profile of aerosol extinction coefficient ε(λ), related to altitude profile of growth function. The ε(λ) spectra are shown to strongly vary for different H, with the largest ε(λ) change occurring in the altitude range H=0-10 m, which is a consequence of gravity effect on the medium-sized and coarse fractions of SSA particles. The model makes it possible to obtain quantitative data on the complex refractive indices of SSA particles for different RH in the wavelength range from 0.2 to 16 μm. The model applicability region was found to be in the following altitude, wind speed, fetch, and relative humidity ranges respectively: H = 0-25 m, U = 3-18 km s-1, X ≤ 120 km, and RH = 40-98%.
Aerosol model MaexPro in the problems related to spectral transparency of the coastal atmosphere
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Results of studying the effect of meteorological parameters on the spectra of aerosol extinction and the results of testing the MaexPro model applicability are presented; and the calculations are compared to available accessible experimental data and calculations using ANAM code. The MaexPro software is shown to calculate adequately the spectra and altitude profiles of aerosol extinction coefficients as functions of wind regime, fetch, and humidity. The results thus obtained explain the effect of decreasing transparency, manifested in the coastal zone, and make it possible to account for indirectly the type of sea salt aerosol (SSA) particles: marine or coastal aerosol. The calculated spectral profiles of aerosol extinction coefficient agree with experimental data and calculations, performed using well-known models.
Attenuation of optical radiation as a function of particle size spectrum
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The results of calculating the spectral profiles of aerosol extinction coefficients ε(λ), performed using MaexPro software for total and partial size spectra of sea salt aerosol (SSA) particles, are presented. The ε(λ) spectra are shown to substantially differ between partial and total size spectra of particles with Δr = 0.01 – 100 μm. The conditions for use of partial size spectra of SSA particles are determined. For instance, in the calculations of energetics of the optical signal in the wavelength range Δλ = 0.2 – 12 μm, it is expedient to use the ε(λ) data, calculated on the basis of particle size distribution functions for the total size spectrum of SSA particles Δr = 0.01-100 μm. The usability of partial spectra Δr = 0.05 – 50 μm, Δr = 0.1 – 50 μm should be decided depending upon specific problems and prescribed accuracy of estimating the attenuation of optical radiation in the atmosphere.
AVHRR-based regional algorithms for retrieving water clarity in Lake Baikal
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The Secchi disk depth is one of the most important physical indicators of the water clarity. When studying Lake Baikal with the surface area of 31,722 sq. km, remote sensing is a necessary tool to assess the Secchi disk depth within the entire lake. To develop regional algorithms for estimating the Secchi disk depth in Lake Baikal is based on the use of a set of coincident AVHRR data and in situ Secchi disk depth measurements. Because of research, the linear algorithm for the periods from the beginning of June to mid-July and from midSeptember to the end of October and the nonlinear algorithm for the period from mid-July to mid-September with the root-mean-square error of 1.9 and 0.9 meters respectively were developed. A series of maps of the distribution of the Secchi disk depth in Lake Baikal for the ice-free period of different years was created using the AVHRR-based regional algorithms.
Anomalous vertical distribution of stratospheric aerosol layer over Tomsk in December 2017 - January 2018
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In the report, we present certain results of studying the vertical distribution of stratospheric aerosol layer (SAL), obtained at the Siberian Lidar Station, Tomsk in December 2017 – January 2018. A block-diagram of lidar is presented. It is shown the aerosol loading of the stratosphere might be due to the occurrence of polar stratospheric clouds (PSC) as a result of transport of Arctic air masses to Tomsk.
Aerosol disturbances of the stratosphere over Tomsk in 2017 according to data of Lidar observations
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In the report, we present and summarize the results of lidar measurements of stratospheric aerosol layer at the Siberian Lidar Station (Tomsk: 56.5°N; 85.0°E) in 2017. Measurement technique with the help of multichannel stationary lidar complex at Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk, is described. The measurements showed that in August – October there were aerosol layers in the altitude range from 14 to 19 km, with R(H) value at maximum having been from 1.3 to 5.8. The trajectory analysis of air mass transport in the atmosphere on the basis of the NOAA HYSPLIT models allowed us to determine that the observed aerosol layers could possibly be due to atmospheric transport of forest fire products from the region of lake Athabasca (Saskatchewan and Alberta provinces, Canada) to the atmosphere.
Spectral bands selection for LIF oil contamination detection on the terrestrial surface on the basis of Jeffreys-Matusita distance
Yury V. Fedotov
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Search of optimal set of spectral bands for laser induced fluorescence (LIF) registration for the task of oil pollution detection is described in the paper. Jeffreys-Matusita distance was used as an optimality criterion. Mathematical modeling showed that 2-3 spectral bands of several dozens nm width were enough for reliable detection of oil pollution.
Analysis of Black Carbon fraction and aerosol scattering coefficient in smokes of remote forest fires and winter urban smogs
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It is revealed on the basis of round-the-clock monitoring measurements of the scattering coefficient of the dry matter of submicron aerosol at the wavelength of 0.51 μm and the mass concentration of absorbing matter at the Aerosol station of IAO SB RAS in 1997–2017, that the average level of the Black Carbon fraction (BC-fraction) of aerosol P for dense winter urban smogs is 3 times greater compared to the smoke of remote forest fires. The average value P for situations with enhanced values of the aerosol scattering coefficient ο > 150 Mm-1 (meteorological visibility range less than 26 km) in forest fire smokes is 0.027±0.01, and in winter urban smog it is 0.091±0.02. The data arrays were selected using the Pcriterion implying the lower values of BC-fraction in the smokes of remote forest fires in comparison with the background aerosol.
Remote sensing and modeling of the evolution of suspended matter in the Sea of Azov
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This paper provides a synergetic approach between numerical modeling and remote sensing of bio-optical water properties. The work demonstrates that appropriate data-assimilation schemes make numerical modeling a suitable and reliable tool for filling the gaps arising due to satellite imagery unavailability and/or cloud covering. In this research we apply the Princeton Ocean Model to the Sea of Azov, assimilating bio-optical indexes (index34 and bbp(555)) from MODIS L2 products. These data identify the presence of suspended matter (mineral suspended matter from river discharges or resuspending as a result of a strong wind), and suspended matter of biological origin. The ad hoc assimilation/correction scheme allows for prediction (and reanalysis) of transport and diffusion of the bio-optical tracers. Results focus on the ability of the method to provide spatial maps that overcome the general issues related to Ocean Color imagery (e.g., cloud cover) and on the comparison between the assimilating and the non-assimilating runs. Methods of joined information analysis are discussed and the quality of model forecasts is estimated depending on the intervals of the satellite data assimilation. Hydrodynamic modeling of the Sea of Azov was carried out for the period of 2013–2014 applying meteorological data of the regional weather forecasting system SKIRON/Eta. The analysis of data coherence helps to detect negative changes to the sea waters, predict them and forecast typical areas and territories subject to anthropogenic impact. The successive data-assimilation algorithm is proved to improve the forecast of suspended matter transfer.
Filtering algorithm of the optical rain gauge data and results of the algorithm usage
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Filtering algorithms for measurement data of the optical rain gauge OPTIOS are presented. Criteria for reducing measurement errors are considered. These errors are associated with registration of objects that are not precipitation particles, and droplets that are broken on elements of the device construction. The examples of the efficiency of proposed filtration methods for precipitation amount measurements are shown.
Dust load in vicinity of boiler-house plants fired with different fuels: case study in Tomsk Oblast
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Study of solid airborne particles emissions from rural boiler-house plants are insufficient. The paper presents the results of comparative analysis of dust pollution in vicinity of rural boiler-house plants in Tomsk Oblast different in parameters and fuel type (coal, gas, oil, wood) based on the study of snow cover. The results showed that value of dust load in comparison of background value in vicinity of studied coal-fired houses were different and depended on fuel consumption rate, presence of dust and gas catchment system, coal depository and vehicle park. The maximum value of dust load is found in vicinity of coal-fired boiler-house plants, where it increases the background from 2 to 16 times. In vicinity of other boiler-house plants dust load is at the background level. In vicinity of different coal-fired boiler-house plants the dust load depends on the fuel consumption, effectiveness of dust and gas collection, availability of outdoor coal storage and vehicle fleet. It is shown that natural gas and wood are the most environmentally friendly fuel from the standpoint of particulate matter emissions.
Characteristic geometric features of the sun glint on the sea surface for satellite optical measurements
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On the base of the top-of-atmosphere radiance calculations carried out with the use of an isotropic version of the CoxMunk model of sea surface slopes distribution and the Sobolev model of light scattering in the atmosphere, the sun glint quantitative characteristics such as its length, maximal width and maximal contrast are presented for measurements of scanning satellite instruments in the visible and near-infrared ranges from 0.4 to 1.6 μm for sea wind speeds from 2 to 14 m/s and atmospheric aerosol optical thicknesses from 0.03 to 0.33.
Optical study of the structure of turbulent flame
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The paper represents the experimental study of the dimensions of turbulent vortices in diffusion flames. The data obtained by the particle image velocimetry method are compared to the data obtained by the thermography method.
Adaptive robust nonparametric estimations of the first four moments of wind velocity components from minisodar measurements
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Since the late 70s, Doppler sodars have been widely used to study the statistical characteristics of wind velocity field in the atmospheric boundary layer and to analyze their dynamics. However, the distribution functions of the wind velocity components are asymmetric with the presence of outliers, which significantly reduces the efficiency of application of the classical parametric methods of statistics. In the report, an algorithm is suggested for nonparametric robust estimations of the first four moments of wind velocity components and their confidence intervals from minisodar measurements in the atmospheric boundary layer.
Variations of atmospheric aerosol optical depth in the Tunka valley during 2004-2017
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Based on the aerosol optical depth (AOD) data, the interannual variability of the atmosphere spectral AOD in the Tunka Valley in 2004-2017 is discussed. The background, mean and extreme values of AOD are obtained. It is noted that the Tunka Valley belongs to a group of regions characterized by a seasonal course of atmospheric transparency with a maximum in the autumn-winter period and a minimum of the spring-year period.
Annual behavior of Angstrom exponent of the aerosol absorption coefficients in the visible wavelength range upon the results of measurements at the aerosol station of IAO SB RAS
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The seasonal and inter-annual variability of the monthly average values of the Angstrom exponent of aerosol absorption in the wavelength range 460-630 nm is studied based on the results of measurements of the aerosol absorption coefficients of the dry matter of submicron aerosol at the aerosol station of IAO SB RAS in 2010-2017 in the nearground air layer. For each year and for the entire period, the range of the Angstrom parameter variations, features of its average annual behavior and inter-annual dynamics are analyzed. It is revealed that the annual variability of the monthly average values of the parameter is characterized by minimum values of ∼1.0 ÷ 1.4 in winter and their increase up to 1.8 ÷ 2.4 in the warm period of year. It is shown that increase of the Angstrom exponent is caused mainly by the effect of smokes from Siberian forest fires, as well as vegetation fires in the spring and autumn seasons.
Backscattering by hexagonal ice crystals with large distortion angles
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In this paper, the calculation and the theoretical investigation of backscattering cross section were carried out as well as a lidar and linear depolarization ratios for the random oriented hexagonal ice columns. The right dihedral angle of the hexagonal ice column was distorted in a range from 0°(regular particle) to 50°. All calculations were obtained within the framework of the physical optics approximation. A wavelength of the incident light was assumed to be 1.064 μm, an index of refraction was taken as 1.3004. It has been shown that if the distortion of a right dihedral angle of the hexagonal ice column is larger than 10°, the secondary maximums in the backscattering cross section become observable due to a new type of the optical beams trajectory. Also, during the averaging over the particle distortion angle a linear depolarization ratio for the column could reach the value close to 0.7 relative units.
Backscattering matrices calculation for atmospheric ice crystals within the physical optics approximation with absorption effect
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In this work light absorption effect for atmospheric ice crystals for near-infrared electromagnetic spectrum is presented. The software for calculating the scattering matrices was modified for a crystal with absorption. The dependence of the M11 element of the scattering matrix on the zenith angle has been received within the physical optics approximation for three wavelengths: 0.532 μm, 1.064 μm, 1.6 μm, for convex and non-convex crystals, and for two conditions: with absorption factor and without it. The comparison of the M11 element of the scattering matrix for these conditions shows negligible changing of intensity for 0.532 μm and 1.064 μm wavelengths and significant decrease of intensity for 1.6 μm.
Cuvette-thermostat for creation of uniform distribution of vapor concentration of high-energy materials
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A design of a thermostated cuvette is proposed that ensures the stability and repeatability of the vapor concentration distribution of high-energy materials during the evaluation tests of the lidar detector.
Decreased ozone content over Western Siberia and Tomsk in winter 2017-2018 according to lidar measurements and Aura OMI/MLS data
O. E. Bazhenov
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In December 2017 and January 2018, the total ozone content was much lower than normal over Tomsk and northern territory of Russia, based on Aura OMI data. The lidar measurements of vertical ozone distribution revealed that ozone maximum shifted toward lower altitudes in January, and in December it was also smaller in magnitude. Moreover, lidar measurements showed the presence of aerosol layers over Tomsk, which, together with lowered temperatures in the stratosphere according to Aura MLS data, might signify the presence of polar stratospheric clouds (PSC). Thus, in December 2017 and January 2018 in the atmosphere over Tomsk the temperatures were much lower than normal and below PSC formation threshold, the altitude and magnitude of ozone maximum were much lower than normal, and the observation site had been under the influence of Arctic air masses with decreased ozone and increased water vapor contents.
Increasing the efficiency of the laser fragmentation/laser-induced fluorescence method for the detection of vapors of high-energy materials
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A method is proposed for increasing the efficiency of the laser fragmentation/laser-induced fluorescence method for the detection of vapors of high-energy materials by selecting a time delay between the fragmenting laser pulse and the optical pumping pulse of NO fragments.
Urban and regional classes of aerosol taking Beijing and Moscow as examples
A. C. Emilenko,
Geng-Chen Wang,
V. M. Kopeikin,
et al.
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Current paper reports analysis of the long-term observations of black carbon and sub-micrometer aerosol in the bottom layer atmospheres of Beijing and Moscow. The results of the black carbon measurements are shown to permit defining the tendency in variability of the urban fine aerosol.
Nonlinear optical methods for diagnostics of liquid mixtures
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It were analyzed the nonlinear optical methods of diagnostics of binary mixtures - the thermal lens method and dynamical holography method. In two-component fluid (binary mixture) the heat flow can cause concentration stream arising from occurrence of thermodiffusion phenomenon (Soret effect). As a result these phenomenon changes the magnitude of the transport coefficients of the mixture. It was developed the theory of the light induced heat and mass transfer, taking into account the cross interaction between the heat and mass flows as well as the presence of optical feedback. The results are relevant to the optical diagnostics of the binary liquid mixtures and nanofluids.
Fiber optical method of nanoparticles diagnostics in liquid
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This paper analyzed the light induced lens response at the fiber optics scheme in transparent nanosuspension with electrostrictive nonlinearity. Ii was proposed the simple model of the phenomenon which can be used for describing the fiber optics experimental results in the nanosuspension. The received expression shows the monotonous growth (as the parabolic low) of the collected power versus the input power in ideal gas model of the nanoparticles ensemble. The thermal contribution due to Dufour effect is characterized by the negative sign and decreases the total response. The results are relevant to the study of the nonlinearity of the nanosuspension and optical diagnostics of such materials.
Studing the effect of low-amplitude pressure fluctuations on the field of temperatures in flame using thermography
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This paper represents an experimental study of the effect of low-amplitude external-pressure fluctuations on the field of temperatures in flame during the combustion of some liquid hydrocarbon fuels.
Multiwave high spectral resolution lidar for studying Asian dust
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Asian dust is generated and transferred subsequently over long distances every year. This phenomenon affects significantly the environment, agriculture, and health of people. Lidar sensing plays a leading role in studies of this phenomenon, since it allows the spatio-temporal distribution of optical characteristics of the dust and its effect on the propagation of solar radiation in the Earth's atmosphere to be registered. Taking into account these possibilities, a multiwave high resolution lidar has been designed and constructed for studying Asian dust. The lidar is mounted in Daejeon, Republic of Korea. Preliminary measurements showed the effectiveness of the proposed lidar concept. This work was supported in part Ministry of Education and Science of the Russian Federation within the framework of the Tomsk State University Academic D. I. Mendeleev Fund Program and the Korea Meteorological Administration Research and Development Program (Grant No. KMI2017-6030).
Evaluation of the complete evaporation time for two interacting atmospheric aerosol drops by operator methods
A. S. Khasanov
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The process of evaporation in diffusion mode is considered by using linear operators approach for two interacting aerosol drops. A formula for the correction factor to the formula for the complete evaporation time of a single aerosol drop is given in the case of two identical drops. The graph of the correction coefficient as a function of the center distance of the drops is presented.
Reconstruction or particle size distribution and refractive index using agglomerated debris particles from sky polarization measurements
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An algorithm for reconstruction particle size distribution function and refractive index is proposed. The algorithm uses agglomerated debris particle model as most convenient to represent particles shape of dust and urban aerosols for calculation polarization properties. Algorithm involve three model functions of particles size distribution: power law, single-mode lognormal, two-mode lognormal, which are parametrized by one, two and five coecients correspondingly in case of polarization measurements.
Variations of microphysical and optical characteristics of atmospheric aerosol in transition zone "land-ocean" based on data of lidar sensing
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The results of variations in the microphysical and optical characteristics of atmospheric aerosol in the transition zone "land-ocean" in the Far Eastern region, Primorsky Kray, Vladivostok are analyzed. The data of measurements for the period from 21.02.2016 to 08.12.2017 are analyzed. The values of the height of the planetary boundary layer (PBL) characteristic for the region were obtained. The average value of the height of PBL for 2016 was (2605±532) m, for 2017 (2501±435) m. Seasonal changes in the height of PBL were considered and an insignificant decrease in the height of the PBL in the spring and autumn of 2017 compared with the same period in 2016, the difference was about 300 m. The values of the real and imaginary part of the refractive index of atmospheric aerosol were obtained for the period from 2016 to 2017. The predominance of an aerosol with a small value (about 1.31-1.36) of the actual part of the refractive index for 2016 compared with 2017 is noted. There are particles of large volumes (17 μm3) for altitudes up to 1 km in 2016 compared to 2017 (11 μm3). The values of the atmosphere optical depth for an altitude of up to 3 km for wavelengths of 355 nm and 532 nm are calculated. It is established that the maximum optical depth acquires in the spring period and reaches to 1.15 for a wavelength of 355 nm and to 0.51 for a wavelength of 532 nm.
Estimation of the contribution of coarse aerosol into extinction of radiation in the wavelength range 0.45 – 3.9 mkm
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The paper analyzes the results of a ten-year long round-the-clock measurements of the atmospheric spectral transmittance of the atmosphere on a horizontal 1 km long near-surface path. Measurements were carried out in the suburb of Tomsk in 1997-2006 since March till October. More than 10,000 hourly average spectra of aerosol extinction coefficients were obtained in the wavelength range 0.45 to 3.9 μm. The role of coarse aerosol in the extinction of visible and IR radiation was estimated. It is shown that the most probable fraction of extinction by coarse aerosol at the wavelengths of 0.45, 0.55 and 1.06 μm, is 17, 22 and 50%, respectively.
Lidar system for ozone sensing in the upper troposphere – stratosphere
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For studying the ozone dynamics in the region of tropopause and stratosphere-troposphere exchange, and for monitoring the global ozonosphere changes, at the Siberian Lidar Station of V.E. Zuev Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences in Tomsk (56.5°N, 85.0°E) a lidar system measures the vertical ozone distribution in the upper troposphere – stratosphere. Sensing is performed using the method of differential absorption and scattering at wavelength pairs 299/341 and 308/353 nm. The lidar system covers the altitude range ~5-45 km.
Effectiveness of the MFAS method for retrieval of height profiles of speed and direction of the wind from measurements by a Windcube 200s lidar
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The method of maximum of the function of accumulated spectra (MFAS) was used for the first time to estimate the wind velocity vector from measurements by a micropulsed coherent Doppler lidar (MPCDL) with conical scanning by the probing beam. In the experiment with a Windcube 200s MPCDL, it is found that the use of MFAS allows an increase in the maximum height of retrieval of the vertical profiles of the wind speed and direction by an average of 30% in comparison with the filtered sine-wave fitting.
Scattering matrixes of hexagonal ice crystals of cirrus clouds calculated for problems of radiation balance
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The scattering (Mueller) matrix has been calculated for the ice crystals of cirrus clouds within the framework of both the geometrical-optics and physical-optics approximations. It is shown that the geometrical-optics solution matches its physical-optics counterpart rather well at the intervals of the zenith scattering angles between 20° – 160° except some deviations in the regions of the halos of 22° and 46°. However, the difference between these solutions is essential in the vicinity of the forward and backward scattering directions. In particular, we show that the geometrical-optical singularity known for the element M11 at the backward scattering direction is accompanied by sign-changing contributions from different ray-trajectories for other elements of the Mueller matrix that was known earlier. These sign-changing peculiarities are inherent to the physical-optics solution as well.
Detection of short waves by the images of the two all-sky cameras
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The purpose of the study is to identify the features of the characteristics and dynamics of internal gravity waves (IGW) in the mesopause region of high latitudes. These waves play an important role in the thermodynamic balance of the atmosphere, thereby also in the formation of the climate. Also, due to the increase in the amplitude of these waves as they penetrate to higher altitudes, it becomes possible to detect them in the upper layers of the atmosphere. The short-period gravity waves by the images of two all-sky cameras, registered at different heights (~97кm and ~87кm) are detected. The first camera detects gravity waves in the visible region by emission of atomic oxygen (557,7 nm) at a height of 97 km. Second camera detects hydroxyl molecule emission in the near infrared region at a height of 87 km. Both cameras installed at Maymaga station (63°N, 129.5°E). To visualize and process the data of the all-sky cameras, a time differencing (TD) method was used. For gravitational waves with periods greater than the survey frequency, the TD-picture intensifies the contrast in areas where waves move, amplify or weaken. According to the cameras, horizontal characteristics of IGW (direction of propagation, velocity, period and wavelength) were obtained using the example of one night.
Studying the resistance to fire of wood under the different type of thermal impact while forest fires
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The paper describes the study of the ignition of wood samples treated with a flame retardant in the presence of different ignition sources (firebrands, pine needle litter) under the laboratory conditions, and to obtain data on fire resistance of wood samples exposed to heat. The charring depth of the wood samples was determined depending on the type of wood, as well as on the type of the fire retardant used. The experimental results show that fire retardants significantly increase the protective properties of wood exposed to firebrands.
Spatiotemporal visualization of wind turbulence from measurements by a Windcube 200s lidar in the atmospheric boundary layer
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The results of spatiotemporal visualization of the kinetic energy of turbulence, its dissipation rate, and integral scale of turbulence from measurements by a Windcube 200s lidar with the use of the conical scanning by the probing beam in the atmospheric boundary layer are presented. When evaluating the parameters of wind turbulence, the lidar data filtering procedure was applied. This procedure allows obtaining acceptable results with a non-zero probability of bad estimate of the radial velocity.
Retrieval of the vertical distribution of aerosol microphysical characteristics from lidar measurements in Tomsk
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Regular lidar measurements of the vertical distribution of aerosol optical parameters are carried out in Tomsk (56°N, 85°E) since April, 2006. A method is proposed for joint determination of two aerosol microphysical characteristics: the complex refractive index m=mreal + i*mimage and the spherical-particle size distribution function U(r) from the data of the nighttime vertical lidar sensing at the wavelengths 355-1064 nm. Section 2 is devoted to the theoretical aspects of retrieving the size distribution function U(r) assuming a known complex refractive index m. It is shown that the coarse fraction cannot be retrieved unambiguously. The statistical regularization method offers an unambiguous estimation of U(r) for the mean radius up to 3 μm, and gives an admissible estimate for larger radii. When estimating U(r) and m together (section 3), the retrieved refractive index is non-linearly related to the optical coefficients and the distribution function, which leads to appearance of different, including false values of m. A simultaneous use of several functionals gives a better estimate of m due to different sets of the respective optical characteristics.
About algorithms for calculation of the structural characteristic of temperature fluctuations in acoustic meteorological systems
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In ultrasonic equipment (anemometers and thermometers) for measurements of parameters of atmospheric turbulence usually use the standard algorithm of calculation of parameters from the temporary structural functions constructed on the registered data. Kolmogorov-Obukhov's law is the cornerstone of the algorithm. As shows experience of use of ultrasonic measuring instruments, such approach can lead to considerable errors. Therefore, a more advanced algorithm for calculating parameters is proposed, which makes it possible to more accurately estimate the structural characteristics of turbulent fluctuations with an error of not worse than 10%.
Lidar investigation of wind turbulence on the coastal zone of Lake Baikal at presence of a low-level jet in the atmosphere
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To study the peculiarities of wind turbulence in the presence of a low-level jet (LLJ) in the atmospheric boundary layer, we used the raw data measured by a Stream Line coherent Doppler lidar on the coast of Lake Baikal in the summer of 2015. From these data, the height and time distributions of the of turbulent energy dissipation rate, the variance of wind speed and the integral scale of turbulence were reconstructed. For the first time from lidar measurements, quantitative estimates of the dissipation rate and the integral scale of turbulence inside the LLJ were obtained with a sufficiently high accuracy. An excess of the dissipation rate by 1-2 orders in the lower part of the LLJ above the corresponding value in the upper part of the LLJ is revealed. In the center of the jet stream, the integral scale of turbulence is of the order of 100 m, which is 2-3 times less than the effective thickness of the LLJ.
Typical shapes of atmospheric ice crystals in the surface layer of the atmosphere from microscopic observation in 2017-2018
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The report analyzes the data of microscopic observation of atmospheric ice crystal particles in the surface layer of the atmosphere. Observations were conducted in Tomsk during the winter of 2017-2018. The results of observations are used to create an adequate microphysical model of atmospheric ice crystals for solving the light scattering problem by the method of the physical optics.
Hardware-software complex for studying the spatiotemporal structure of the fields of turbulent fluctuations of temperature and wind
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The new hardware-software ultrasonic complex AMK-03-4 to measure the characteristics of turbulent meteorological fields is created. In contrast to similar measuring instruments, the complex consists of four identical ultrasonic anemometers. The design of a complex allows not only to register the turbulent characteristics, but also statistical characteristics of spatial derivative turbulent pulsations of temperature and an orthogonal wind speed components along each of axes of the Cartesian coordinate system. It allows to investigate spatial-temporary structure of turbulent meteorological fields of a surface layer of the atmosphere for the subsequent applications in similarity theory. Besides, the standard algorithm of calculation of structural characteristics of fluctuations of temperature and wind speed applying in ultrasonic anemometers is improved that allowed to lower errors of their measurement considerably.
Multisensor oriented pyranometer
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This paper describes the multisensor oriented pyranometer with no moving parts for measuring total, direct and diffuse irradiance, and sunshine duration.
Absorbing aerosol effect on the diffuse attenuation coefficient for downwelling irradiance at 490 nm indicator recovery quality on the northwestern shelf of the Black Sea
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Coefficient of diffuse attenuation coefficient for downwelling irradiance at wavelength 490 nm (Kd (490)), obtained from measurements of the MODIS device from the Aqua satellite and the effect of an absorbing aerosol on a standard satellite product was studied. For this the event of absorbing aerosol transfer over the Black Sea northwestern shelf area which was diagnosed at the AERONET-OC Gloria station in the summer season of 2014 was considered. It was shown that the presence of an absorbing aerosol in the atmosphere leads to an overestimation of the standard satellite product: Kd (490) in comparison with its value calculated from the ascending radiation spectrum direct measurements at the above-mentioned AERONET- OC.
Concentration of biogenic elements, fluorescent characteristics, and direction of СО2 fluxes over the water area of Lake Baikal in the spring periods of 2016 and 2017
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This study continues the thorough investigation of the impact of physical, hydrological, chemical, and biological processes on the СО2 gas exchange in the water-atmosphere system at Lake Baikal. The results of measurements of the СО2 flux direction, biogenic elements, and fluorescent characteristics over the entire Baikal territory in the spring periods of 2016 (from 25.05 to 06.06.) and 2017 (25.05 to 05.06) are compared. Fluorescent characteristics were measured with a flow-through fluorimeter, whose operation is based on the principle of pulse-amplitude modulation. It is shown that most significant year-to-year differences in the analyzed characteristics are observed in the Middle Baikal region. In 2016, the surface temperature in this zone approaches 40°C, and probably the vertical exchange process manifests itself here.
Assessment of the spatial distribution of the direction of greenhouse gas fluxes at the Krasnoyarsk water reservoir in the warm season of 2017
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From the results of three measurement cycles, it is shown that significant dynamics is observed in the spatial distribution of the amplitude and direction of carbon dioxide flux at the water reservoir of the Krasnoyarsk hydro power plant (HPP) in the summer-fall season. In June and August, the sink of carbon dioxide from the atmosphere to the water surface was observed all over the area of the water reservoir and at the territory downstream of the dam. In September, the entire water reservoir was mostly a source of carbon dioxide. It was found that in the three measurement periods the value of ΔРСН4 is positive, that is, in the summer-fall period the Krasnoyarsk water reservoir is a source of methane inflow into the atmosphere. The widest differences are observed just near the dam of the Krasnoyarsk HPP (from minimal in June to maximal in September).
Study of carbonaceous gases fluxes at the Irkutsk water reservoir in the warm season
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To study the spatial distribution of the direction of carbon dioxide and methane fluxes at the Irkutsk water reservoir and their variability in the warm season, three measurement cycles covering the period from June to September 2018 were conducted. The content of carbon dioxide and methane was recorded continuously in the surface water and near-surface atmosphere along the ship route from Lake Baikal to the dam in the upstream pool and the dam area in the downstream pool. It is shown that in the summer-fall period the intense photosynthetic activity of biota leads to a significant decrease in the carbon dioxide concentration in water, and the Irkutsk water reservoir is an absorber of carbon dioxide. In the same period, the results of СН4 study indicate that in the summer-fall period the water reservoir is a source of methane inflow into the atmosphere.
Monitoring cirrus clouds over Tomsk and measurements of solar radiation in the atmospheric surface layer
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A complex experiment on the investigation of radiation characteristics of cirrus is performing since 2016. In the experiment, solar radiation fluxes are measured near the Earth’s surface and the orientation degree of ice crystals in cirrus is estimated using a polarization lidar. Results of the experiment are discussed. Significant effect of the orientation degree of cirrus particles on the transmission of solar radiation is found in a number of experiments.
Optical characteristics of contrails according to polarization lidar sensing data
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In the present report, results of the experiment on polarization laser sensing of contrails performed for one and a half days are discussed. The altitudes of boundaries of the aerosol layers, their backscattering matrices, optical thicknesses, and scattering ratios are determined. The vertical profiles of lidar returns are analyzed. The results are compared with the meteorological data at the altitudes of formation of high-level clouds.
Identification of the marine aerosol by the CALIPSO radiometer over the Black Sea for 2017
Show abstract
Coefficient of vertical light attenuation at wavelength 490 nm (Kd (490)), obtained from measurements of the MODIS device from the Aqua satellite and the effect of an absorbing aerosol on a standard satellite product was studied. For this The event of absorbing aerosol transfer over the Black Sea northwestern shelf area which was diagnosed at the AERONET-OC Gloria station in the summer season of 2014 was considered. It was shown that the presence of an absorbing aerosol in the atmosphere leads to an overestimation of the standard satellite product: the diffuse light attenuation coefficient at 490 nm (Kd (490)) in comparison with its value calculated from the ascending radiation spectrum direct measurements at the above-mentioned AERONET- OC.
Diurnal behavior of aerosol hygro- and thermooptical parameters in the atmosphere of Tomsk region
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To study the diurnal behavior of hygro- and thermooptical parameters, the cycles of intensive measurements with artificial humidification and heating of the aerosol under study were carried out four to six times a day. The parameter of condensation activity γ characterizes variability of the aerosol scattering coefficient under the change of the relative humidity of air, and the thermooptical parameters are determined by the decrease of the volume concentration of particles in the respective temperature range. Diurnal behavior of the parameter of condensation activity is the most pronounced in spring. Its characteristic peculiarities are maximum in the daytime (~ 3 pm) and minimum in the evening (~10 pm). Diurnal behavior of the parameter determining the aerosol fraction evaporated in the temperature range 100 – 250°C also is well pronounced.
Lidar observations of the regional transport and formation of aerosol fields in the background and urban areas
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The description of the apparatus and the results of synchronous observations of the structure of aerosol fields in urban areas and in background conditions are given. Continuous day and night observations were carried out by the modernized lidar CIMEL CE372 (the background experimental site) and the stationary lidar "LOZA-S" (Tomsk, Akademgorodok). The main task of the research is to determine the stratification characteristics of aerosol layers in different synoptic conditions and to show the city's contribution to the aerosol structure of the boundary layer.
Correlation of statistical characteristics of ensembles of the droplet clouds particles and polarization characteristics of lidar return
Denis V. Kostin,
Valentina V. Bryukhanova,
Anna N. Bushmakina
Show abstract
The Earth's radiation budget depends on form and sizes of cloud particles and from their orientation in the space if the crystal particles where are in cloud. The particle size distribution function is the most informative about the characteristic features of a dispersed medium. As a rule, the particles size distribution of droplet cloud is described by a gamma distribution or a lognormal distribution. The results of a comparative analysis of the statistical characteristics of droplet cloud particles ensembles on the basis of the gamma distribution and lognormal distribution and their correlation with the polarization characteristics of the lidar return are discussed in the report.
Effect of the polarization state of sensing radiation on the extinction of water-milk suspension
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Determining the aerosol microphysical properties is an important scientific and applied problem. In practice, most often the interpretation of lidar data is based on the laser sensing equation, which is valid for media with a small optical thickness. During sensing of optically dense formations, it is necessary to take into account the contribution of multiple scattering to the lidar return. In addition to significant attenuation, multiple scattering leads to the depolarization of radiation. The purpose of the present report is to discuss the effect of the polarization state of sensing radiation on its extinction in water-milk suspension.
Determination of the set of optical-meteorological parameters from satellite data in algorithms of atmospheric correction
M. V. Engel,
M. V. Tarasenkov
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The paper presents a technique for determination of the set of optical-meteorological parameters of the atmosphere obtained on the basis of MODIS Atmosphere Products. This technique uses the file naming convention with measurement data of the MODIS spectroradiometer for determination of the time correspondence and metadata for determination of the spatial correspondence.
Air quality biomonitoring with epiphytic lichens and mosses
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In recent decades increasing attention is paid to biomonitoring of air quality. In this paper epiphytic mosses and lichens were chosen as bioindicators to estimate the level of atmospheric pollution. The paper presents the results of elemental analysis, as well as analysis of the carbon and nitrogen stable isotope ratios in mosses and lichens of Tomsk and Prokopyevsk (Russia, Western Siberia). The mean values of lichens δ13C for Prokopyevsk and Tomsk are ca. –26‰ and –27‰, respectively. The mean values of δ13C in mosses are similar for both cities (ca. –30‰). However, δ13C of some mosses samples collected in Prokopyevsk have lighter values (ca. –34‰), probably due to the mine methane influence. The mean δ15N values for mosses and lichens for Tomsk (+2.1 and –1.3‰, respectively) is heavier compared to the mean δ15N values for Prokopyevsk (δ15N for mosses = –1‰ and δ15N for lichens = –5‰). Based on this, it can be concluded that Tomsk has a large anthropogenic load in terms of emissions of nitrogen-containing compounds.
Research of radiation extinction coefficient due to midges in the ground layer of the atmosphere for Autumn conditions of Western Siberia
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The research of radiation extinction coefficient due to midges (RECM) for background conditions of Western Siberia was conducted from August 19 to September 20, 2017. For this autumn period, assessment of average RECM value was 0.038 km-1. In the daily course of RECM two maxima are revealed: the first insignificant maximum falls on 9 o'clock in the morning, the second considerable day maximum - on 15-16 hours.
Comparison of spatial distribution and seasonal variation of the bioluminescence and chlorophyll-a concentration fields in the northern part of the Black Sea
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Modern methodology in analysing the spatial distribution and functional characteristics of plankton combines methods classical for the planktology and methods used in investigation of pelagic zone by the parameters of biophysical (bioluminescent, fluorescent, etc.) fields they produce. The use of real-time information systems is one of the advantages of biophysical methods. It allows evaluation of the correlations between plankton structural features and structure of hydrophysical fields, and ultimately leads to the development of predictive pelagic ecosystem models. Data collected within five marine research cruises were used to analyze seasonal variability of the bioluminescence field of the active layer of the Black Sea. Chlorophyll a concentration variability in the surface waters was analyzed based on the remote sensing data. Correlation coefficients between bioluminescence field parameters and chlorophyll a concentration had opposite signs in different seasons owing to the seasonal changes in the taxonomic structure of the phytoplankton communities.
Ground-based spectrographs for measurement of rotational temperature OH (3-1) installed at a meridional network in Yakutia
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Characteristics of spectrographs intended for measurement of radiation intensity of the OH (3-1) band and determination of the atmosphere temperature at a glow height by its rotational structure are presented. The Shamrock 303i spectrographs supplied by high-sensitive infrared InGaAs photodiode register of Andor Technolog company have been installed at the Maimaga (63 ° N, 129.5 ° E) and Tixie (71.5 ° N, 129 ° E) stations. The technique of measurement of the rotational temperature, estimation of casual and regular errors is described. The calibration measurements with two spectrographs at Majmaga station have shown that the difference of nightly average values of temperature does not exceed errors of measurement with the device.
Numerical study of extinction matrix in cirrus clouds
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The paper presents the extinction matrix for an ensemble of ice hexagonal plates and columns. The calculations were carried out for particles with characteristic sizes from 10 to 100 μm, for wavelengths from 0.3 to 10 μm, assuming the gamma distribution over particles size width parameter μ<4. It is shown that for the visible range of wavelengths, the extinction matrix of an ensemble of atmospheric ice crystals is unit with a coefficient being equal to the double area of the particle projection. It is also shown that in the IR region this representation of the extinction matrix is valid only for hexagonal columns, bullets and similar crystals with a characteristic size larger than 20 μm for wavelengths less than 8 μm.
Hardware programming implementation of obtaining meteorological data and data of geopositioning based on microcontroller ATmega for application in LIDAR measurements
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This paper offers a hardware programming method to automatically collect,process,transmit and store the meteorological data and data of geopositioning on the basis of the ATmega microcontroller and soft hardware Arduino when logging LIDAR measurements and further application of the data obtained in the processing LIDAR measurements.
Using the data bank of backscattering matrices of IAO SB RAS for interpreting the data of the high-altitude polarization lidar of TSU
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In the paper the analyses of the lidar measurements data of optical parameters of the cirrus clouds over the Tomsk city are presented. The valuation of the microphysical properties of the cirrus clouds was done by the backscattering matrices that were measured by the high-altitude polarization lidar (wavelength is 0.532 μm) from National Research Tomsk State University in 2016-2018. For the interpretation of the laser sensing data we used the backscattering matrices database designed in V.E. Zuev Institute of Atmospheric Optics, Russian Academy of Sciences, Siberian Branch. An attempt to interpret the measured matrix using the quasi-horizontal orientated hexagonal columns with the 1000 μm modal size Lmod is incorrect in view of the fact that the particles with this size are very unlikely in existence of nature. It was demonstrated that the calculated backscattering matrices together with proposed algorithm could be used for the valuation of microphysical properties of the measured backscattering matrices.
Characteristics of suspended matter scattering in the Black Sea waters obtained from the light beam attenuation measurements in summer and autumn of 2016
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The scattering characteristics of suspended matter in seawater obtained during combined processing of the field measurements data of the light beam attenuation coefficient and the information from satellite ocean-color scanners are presented. The model estimation of particles size composition is made. Percent of fine fraction of the suspension and its spatial distribution are shown to correlate with seasonal changes in hydrology of measurements polygon.
Retrieval of microstructure of the near-surface aerosol in the summer period from measurements of horizontal transmittance of the atmosphere in Tomsk
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The time variation of microstructure of the near-surface aerosol in the summer period has been studied based on solving the inverse problem for spectral measurements of aerosol extinction coefficient. Experimental data were obtained in Tomsk on a horizontal path using the measurer of spectral transmittance of the atmosphere at 11 wavelengths in the range from 0.45 to 3.9 μm. The numerical algorithm, based on the method of integral distributions, was used to solve the inverse problem. The volume concentration and the mean radius of aerosol particles with separation into a submicron and coarse fraction are considered. Specific features of the aerosol microstructure during the smoke haze in the atmosphere are determined.
Relations between the aerosol condensation activity and its microstructure in nano- and micrometer particle size range
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The dependence of the size and optical parameters of atmospheric aerosol particles on the relative humidity of air is usually represented by a smooth curve described by a one-parameter formula of the Kasten - Hanel type1,2. However, sometimes, more often in spring, a dramatic increase of the scattering coefficient caused by a phase transition (dissolution) of the particulate matter is observed in a narrow humidity range. In order to estimate, what atmospheric aerosol particles provide for the appearance of the phase transition at wetting, the data on the aerosol microstructure in nano- and micrometer size range were analyzed. The peculiarities of the aerosol microstructure in the cases of the phase transition and its absence are discussed in the paper.
Reflectance model for satellite monitoring of bio-optical characteristics of Gorky reservoir waters
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The first results in development of method for satellite monitoring of the bio-optical water properties of Gorky reservoir as an example of an inland freshwater eutrophic water body are presented. The method is based on the semi-analytical algorithm for the Black Sea and uses the data on the reflectance coefficient of the water column, allowing to calculate the concentrations of optically significant substances (phytoplankton pigments, dissolved organic matter and mineral suspended matter). Field measurements of spectral reflectance were carried out in years 2016 – 2017. Spatial variability of reflectance and factors affecting it were analyzed. Reflectance model used in Black Sea algorithm was adapted to biooptical features of the studied water body. Model calculations of pigment concentration were compared with chlorophyll a content data obtained from water samples analyses. The pigment absorption spectra were calculated, showing the spectral features characteristic of photosynthetic pigments. The ways of further research for algorithm development are determined.
The structure of Stokes vector of double scattering lidar return by clouds
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The work is devoted to polarization remote sensing of droplet clouds in the double-scattering approximation. A numerical simulation of the individual radiation fluxes forming the lidar return is carried out. The main attention is paid to the analysis of the influence of the aerosol formation microstructure on the polarization characteristics of a double scattered radiation.
Investigation of optical surface fouling in natural marine environment
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The results of studying the natural fouling of flat quartz glasses, as well as fouling on the beam attenuation coefficient (BAC) meters’ flat surfaces of objective lens and triple-prism are presented, using the method of spectrophotometry under the same conditions during the plant cover formation. The method based of the obtained empirical data is proposed for registration the biofouling contribution.
Cross-platform software to continue long-term observations with the Brewer spectrophotometer in the face of changing computer platforms: implementing the Model-View architecture
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Recovery of the ozone layer likely caused by prohibiting some ozone-depleting substances under the Montreal Protocol and observed since 1998 is uneven. In this regard, the tasks remain to continue monitoring the ozone layer and to provide the homogeneity of the observations obtained in comparison with the measurements of previous decades. One of the oldest global systems providing ozone data is the network of fully automated Brewer spectrophotometers operated since the earlier 1980s. The existing software for control Brewer spectrophotometer was created more than 35 years ago and is in need of redeveloping to continue long-term observations of in the face of changing computer platforms. A new crossplatform control software for the Brewer is being developed, which is capable of running on computers with modern multitasking operating systems (Windows, Linux, macOS), and at the same time it has a one codebase. In the new software, the Model-View architecture is implemented to separate the code of measurement data (models) from the code of their display to the user (views). The model is responsible for data management and provides an interface for reading and writing this data, and the view retrieves the necessary data from the model, reacting to its changes, and sends the data to the user, placing them properly in the GUI of application. The developed database of the new software for storing measurement data and instrumental constants consists of more than 30 tables and stores about 800 pieces of information. Models are developed in the C++ programming language using the cross-platform Qt framework, and the relational database SQLite is used as a persistent storage. This software allows improving the quality and uniformity of TOC and UV radiation measurements on the Brewer spectrophotometers of the global ozone network.
Chemical composition and space dynamics of aerosol sedimentation in the vicinity of Iskitim cement plant
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The paper presents data on chemical composition of snow cover samples collected in the vicinity of Iskitim cement plant in March of 2017. The high pH values, the presence in large content of Ca2+, Mg2+, Na+, K+, Cl–, NO3 –, SO4 2– and the existence of pair correlations between them assume to be a unique source of pollution, namely the cement plant dust. Chemical thermodynamic modeling the samples equilibrium composition and the space dynamics reconstruction models approve the conclusion.
Dissolved and suspended matter variability in coastal waters: photosynthetic available light
T. Churilova,
V. Suslin,
N. Moiseeva,
et al.
Show abstract
To assess an effect of optically active components (OAC) on water transparency and the spectral features of downwelling irradiance (Ed(λ))in coastal waters several scenarios have been simulated: blooms of planktonic microalgae (with the exception of coccolithophore blooms), resuspension of sediments, incoming of suspended and dissolved organic matter with river/coastal run off. General and specific effects of OAC variability on (Ed(λ)) have been revealed. The general effects are: the OAC increase resulted in decrease of water transparency and narrowing of euphotic layer, which in turn led to decreasing in photosynthetic available radiation (PAR) averaged within the mixed layer from the surface down to the bottom altering the light condition of plankton and benthic algae. Specific effects caused by the differences in the shape of light absorption coefficient spectrum of the OAC are: in the scale of optical depths, the spectral features of (Ed(λ)) varied depending on the relative content of OAC; shift of penetrating irradiance to the longer wavelengths was amplified from phytoplankton to non-algal particles, to colored dissolved organic matter. Values of chlorophyll a concentration and Kd at particular wavelength or spectrally average Kd are not sufficient for correct assessment of underwater light. An additional indicator characterizing the ratio between OAC is required.
Numerical simulation of light scattering in the seawater with arbitrary level of inelastic scattering
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In turbid coastal waters the fluorescence by yellow substance and by chlorophyll affect on the light fields. It would be quit important to take into account the effects of incoherent light scattering more precisely. In this paper, the equation of transfer is written in vector form, in which the spectral matrix of incoherent light scattering is included. The spectral matrices of the reflectance and of the transmittance for a plane-parallel layer are introduced. An analytical solution of the equation for a single and two-fold scattering is written. To get numerical solution a matrix operator method based on the “interaction” principle is proposed. The method is intended for numerical simulation of the light fields in the vertically non-uniform seas illuminated by daylight.
Methods of determining the height of the lower border of clouds from the lidar signal
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The article describes instruments for measuring the height of the cloud base, which are widely used in meteorology, especially as meteorological support for aerodromes. It is noted that there is no single method by which the height of the lower cloud boundary is determined. The methods of processing signals for determining the height of the lower cloud boundary (applicable for automatic recording mode) are presented.
Light absorption by phytoplankton, non-algal particles and colored dissolved organic matter in the Sea of Azov in January and April 2016
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For the first time light absorption by all optically active components (phytoplankton, non-algal particles and colored dissolved organic matter) has been measured in the Sea of Azov. Regional bio-optical properties have been shown for winter and spring seasons.
Doppler fiber lidar wind speed measurement
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The report reviews the existing lidar methods and systems for measuring the wind speed vector. Examples of the successful application of Doppler systems are given and the choice of fiber technologies for constructing laser meters for wind speed and direction.
Methane vertical profiles retrieval from IASI/METOP and TANSO-FTS/GOSAT data
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The joint methane vertical profile retrieval from the thermal infrared (TIR) and shortwave infrared (SWIR) satellite spectra allows to improve the vertical resolution of the spectral data processing method. However, spectrometers with a dense spatial coverage such as IASI/METOP or AIRS/AQUA have only TIR spectrometers, which provide maximum sensitivity for methane content in the middle troposphere. On the other hand, TANSO-FTS/GOSAT is unique spectrometer with both ranges, but it has a rare spatial coverage. The paper describes the technology of using TANSOFTS measurements to constrain the inverse problem solution for vertical methane profile retrieval from multiple IASI spectra (1220-1310 cm-1 ) in the vicinity of a single TANSO-FTS measurement using the 5937-6110 cm-1 range.
Light absorption by non-algal particles and colored dissolved organic matter at the wavelength of 490 nm in the Black Sea in the autumn (2015 and 2016)
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Variability in light absorption by colored dissolved organic matter (ܽαCDOM(λ)),by non-algal particles (αNAP(λ)), and by colored detrital matter (αCDM(λ)) were analyzed in the coastal and deep water regions in the Black sea at the same season (Autumn) to avoid the impact of seasonal variability. The CDOM, NAP and CDM light absorption were parameterized. As result of the parameterization the two parameters were obtained (coefficient et 490 nm and slope coefficient (S):αCDOM(490) and ܵSCDOM;αNAP(490) and SNAP ; αCDM(490) and ܵSCDM. The CDOM contributed mainly in the ܽαCDM(490) in both coastal (79 ± 13%) and deep water (88 ± 6%) regions. It was observed high (in ~order) variability in the αNAP(490) in coastal waters due to resuspension of sediments from the bottom at shallow stations. The average αSNAP values were 0.010 nm-1 in coastal and 0.012 nm-1 in deep water regions. For all dataset the relationship between of ܽαCDM(490) and ܵSCDM was described by power function. This equation can be used for refining of the regional algorithm of ܽαCDM(λ) assessment in the Black Sea based on satellite data. The obtained in this research relative absorption of NAP and CDOM could be used for remote assessment of αNAP (λ) and ܽαCDOM(λ) in the Black Sea.
Dynamics in pigment concentration and light absorption by phytoplankton, non-algal particles and colored dissolved organic matter in the Black Sea coastal waters (near Sevastopol)
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Results of long-term biooptical monitoring and parameterization of light absorption by phytoplankton, non-algal particles ( αNAP(λ)) and colored dissolved organic matter (αCDOM(λ)) in coastal surface waters of the Black Sea near Sevastopol have been presented. Seasonal differences in the relationship between phytoplankton light absorption coefficients and chlorophyll a concentrations, which are associated with annual dynamics in the intracellular pigment concentration and composition in the surface layer of the sea, have been revealed. The αNAP(440) was on ~order increased from off-shore waters to the Sukharnaya Balka, but the αNAP(440) contribution to the total particulate absorption was the same (~ 20-49% based on IQR) at all stations reflecting the correlated variations in phytoplankton and NAP absorption coefficients at ~440 nm. The obtained slope coefficient (SNAP) values varied from 0.010 to 0.014 nm -1 . The CDOM light absorption increased significantly (almost in order) from off-shore waters to the Sukharnaya Balka, but the contribution of αCDOM(440) to total light absorption by particles and dissolved matter changed in the opposite direction: decreased from 40 - 70% to 25 – 45%. The ranges of SCDOM variability in all investigated areas were close (0.017 to 0.020 nm-1 based on IQR). The median of SCDOM was 0.018-0.019 nm-1 . The obtained in this research results will be used for adaptation of the regional algorithms of remote assessment of water quality and productivity indicators for coastal waters near Sevastopol.
Focusing of sonar images as an inverse problem for radiative transfer equation
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The kinetic model, describing sound propagation in the ocean with diffuse reflection by Lambert's cosine law on the bottom surface, is considered. The inverse problem of bottom scattering reconstruction is formulated. The inverse problem is reduced to solving the Fredholm integral equation of the first kind. An iterative algorithm is developed. Numerical experiments for reconstruction of the seabottom scattering coefficient depending on different width of directivity pattern are carried out.
The functions of fluctuations of a laser beam of remote sensing and self-radiation of a flame in modeling a fiery vortex
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On a laboratory scale, a vertical tornado-like flame with a height of up to 1 m and a diameter of the order of 0.05 m was investigated. A laser remote sensing of this flame at several altitudes was carried out. Fluctuations of the self-radiation of the flame in the visible range were recorded at these heights. We calculated the spectral functions of the intensity fluctuations for the probing laser beam and for the fluctuations of the self-radiation of the flame. For these spectral functions, the height dependences of the coordinates of the maxima and the coefficients of the tangent in the highfrequency region are determined.
The analysis of differential absorption method equations for the outgoing radiation two-layer atmosphere
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The analysis of the atmospheric model can be represented as a homogeneous surface layer and another one homogeneous layer 10 km has been performed. Parameters of the layers were defined for the standard atmosphere under the condition that the contribution of the outgoing radiation from the atmosphere in the studied spectral section of absorption lines of methane 1240.980 -1241.020 cm-1, 1240.901 -1240.949 cm-1 is equal to the sum of deposits for the outgoing radiation emitted by the Earth all mixed layers. The system of two equations interconnecting the changes of methane content in each homogeneous layer with the changes of outgoing radiation power for each spectral section was considered.
Research of correlation dependences meteorological parameters
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The paper describes the analysis of correlation dependences between meteorological parameters for a series of observations obtained at station with a synoptic index of 29430. It was shown that the parameters with strong correlation dependences have virtually unchanging correlation coefficient for every time scale of the sample. In the case of meteorological parameters with weak correlation coefficient, there are non-significant jumps in the correlation coefficient values. For meteorological parameters with moderate correlation coefficient, increasing the sample time scale leads to stabilization of correlation coefficient values.
Dynamics of surface carbon dioxide and methane concentrations on the Arctic Belyy Island in 2015-2017 summertime
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The paper presents some results of greenhouse gases in situ measurements in 2015-2017 summertime from a high Arctic Belyy Island (Russia). The atmospheric CO2 concentration has increased by 3.1 ppm per year, which is 1.5 times higher than the mean annual global rate during last 10 years. However, the absolute CO2 levels were significantly less than the global background, which exceeded 400 ppm in 2015. The CH4 content had not changed, but in summer periods tundra ecosystem of the island was shown to remain a local net CH4 source in comparison to marine ecosystem. Possible mechanisms of forming mean diurnal cycles of CO2 and CH4 concentration are discussed. The temperature dependences of the measured parameters are established, indicating a significant sensitivity of carbon balance in the arctic tundra to the air temperature variability.
Investigation of the engine-gear vortex with LIDAR and CFD
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The final approach and touchdown of a landing aircraft is studied numerically with a hybrid RANS/LES approach, as well as a pulsed coherent LIDAR system. Particular emphasis is put on the ground effect, the engine-gear vortex and the wake vortex evolution before and after touchdown. We compare CFD results with LIDAR measurement data collected in a recent campaign at Vienna airport. The radial velocity method was applied to retrieve vortex position and circulation. The vortex structures predicted by the simulations are clearly visible in those measurements. Simulated tangential velocity profiles are compared with vortex model profiles. It is observed that the standard vortex model can be improved including mirror vortices.
Preliminary estimation of forest fire danger using LANDSAT images over Baikal Lake basin forests
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Forest fires are a significant factor that affects the natural heritage of our planet – the lake Baikal basin. Moreover, often this impact is negative and causes damage to the forest areas of the region. The main condition for effective forest management and fire protection is the availability of reliable and comprehensive static and dynamic information on the state of the forest fund. The report provides a description of the methodology for preliminary analysis of the structure of the forest and assessing forest fire danger. LANDSAT images are used as primary information. One of the territories of the Baikal region is considered. LANDSAT images were used for 2015.
The daily variation of the concentration of suspended particles in the surface layer of the atmosphere of the village Berezovka (Krasnoyarsk region)
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PM10 concentrations in the surface layer of the atmosphere of Berezovka are 2-3 times higher in winter than in summer. The daily variation of suspended particle concentrations is characterized by two maxima and two minima. It is more pronounced in January and February than in June and July. Winter maxima are mainly due to the time intervals of 9-11 and 19-21 hours, and summer-on 9-11 and 22-23 h. Minima are due to 4-5 and 15-17 h in winter, and in summer - 4-6 and 14-18 h. The daily variation of PM2.5 is similar to the daily variation of PM10 in winter. The difference is that the concentration of PM2,5 increases to values that are significantly higher in the evening than in the afternoon. Air pollution is associated with coal heating of individual houses in the village and the daily variation of the concentration of PM is determined by the heating regime of dwellings.
Contours of spectral lines and temporal characteristics of emission spectra in plasma of optical breakdown generated by single femtosecond laser pulses on surface of water solutions
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The spectral and temporal characteristics of plasma radiation (contours and kinetics of the intensity of spectral lines) generated by a Ti:Sa femtosecond laser pulses on the surface of water solutions are investigated. The best parameters of optical spectra registration and of the laser radiation are determined to improve the metrological characteristics of timeresolved femtosecond laser induced breakdown spectroscopy.
Dependence of fluorescence intensity on chlorophyll a concentration and light absorption coefficients by phytoplankton in the Black Sea (October 2017)
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Dependence of fluorescence intensity and light absorption on chlorophyll a concentration was investigated in designated layers of euphotic zone of the Black Sea in October 2017, when waters were seasonally stratified. Chlorophyll a specific light absorption was obtained to decrease with depth (from layer to layer), which resulted in a change of coefficient of relationship between concentration of chlorophyll a and its fluorescence intensity.
Kinetics of light-induced sedimentation of nanoparticles
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The theoretical analysis of the light-induced mass transport task was executed in the dispersed medium in a homogeneous light field. We have discussed the model of sedimentation of nanoparticles by using the laser effect in liquid. It was received the solution of one-dimensional task of the light induced mass transfer as depending on intensity of laser beam. The proposed model of sedimentation of nanoparticles is relevant in the study of dispersed liquid-phase media, as well as in the optical diagnostics of such materials.
Optical diagnostics of sedimentation of nanoparticles in liquid
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A theoretical model of the pseudo-prism method for diagnostics of two-component media in a gravitational field is considered. An expression is obtained for the angle of deflection of the probe signal with allowance for the Dufour effect.
Nitrogen oxides in the atmosphere of coastal areas of Lake Baikal: sources and possible impact on the ecosystem of the lake
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The research is focused on the distribution of nitrogen oxide concentrations in the atmosphere above Lake Baikal, the determination of the largest sources of emission, and a quantitative assessment of their possible contribution to the content of nitrates in the near shore waters of the lake. The paper presents the results of measurements of nitrogen oxide concentrations above the water area of the Baikal in the summer. In general, low background concentrations of nitrogen oxides prevailed, the excess was recorded in the northern part of the lake. An analysis and a calculation of emissions into the atmosphere from power facilities in the near-shore areas of the lake were carried out. In the northern part of Lake Baikal, the central coal-fired boiler plant in the town of Severobaikalsk could become a source of nitrogen oxides emission. The plume from the boiler was visually observed above the near shore waters. This boiler plant is the largest energy facility and the main source of emissions of pollutants into the atmosphere. Deposition of nitrogen oxides from such plumes can temporarily and locally cause an increase in nitrate concentrations in the near shore waters by 3-5% per day. In turn, the high content of nitrates in the water contributes to the growth of biomass of some algae species and thus affects the entire ecosystem of the lake. Water transport can also be a significant source of nitrogen oxides above the water area of the lake, but its contribution to the pollution of Lake Baikal is not sufficiently investigated.
Generalization of the formula for the complete evaporation time of single atmospheric aerosol drops by operator methods for two drops of arbitrary radii
A. S. Khasanov Sr.
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The process of evaporation in diffusion mode is considered by using linear operators approach for two interacting aerosol drops of arbitrary radii. The formula for the complete evaporation time of single aerosol drops is generalized for two drops of arbitrary radii for arbitrary distances between them. The results of calculations using these formulas, as well as approximate engineering formulas are presented.
Depolarization calibration of the polarization lidar by using fitting method
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As the non-spherical particles could be distinguished from spherical particles easily from polarization lidar measurement, polarization lidar was widely employed in the atmospheric measurements. However, it is very difficult to retrial the particle properties quantitatively from depolarization measurement due to the complex vector scattering model and the calibration of depolarization measurement. In this paper, a method for depolarization calibration of polarization lidar was introduced, and the offset angle of the half-wave plate and gain ratio could be determined exactly by using fitting method. The simulation and lidar measurements indicate that the polarization lidar could be calibrated well by using this method.
Limit of detection and dynamics of fluoresence spectrums of different types of oil products by induced femtosecond pulses
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Limits of detection of concentrations for dissolved samples of Medium fuel oil and Marine gas oil were measured by two frequency of laser induced fluorescence with 266 and 400 wave length and 100 fs pulses duration. Dynamics of fluorescence spectrums of different types of oil products was investigated.
Method of femtosecond laser-induced breakdown spectroscopy for monitoring the seawater elemental composition
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Experimental studies have been carried out to determine the limits of the detection of chemical elements (manganese, magnesium, lead, strontium) in water, when plasma generated by femtosecond laser pulses on the aqueous solutions surface, depending on the parameters of laser radiation (pulse duration, energy and the mode of focusing). The emission lines of chemical elements in plasma generated in a aqueous solution by Ti-Sapphire laser complex at a central wavelength of 800 nm, using focusing lenses with different focal lengths, and also for collimated beams under laboratory conditions are registered.
Using wind profiler data to identify classification of rainfall
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The characteristics of wind profile radar signal-to-noise ratio, spectral width and vertical velocity under different rainfall in summer are summarized respectively. The range of signal-to-noise ratio, spectral width and vertical velocity varies with the level of rainfall amount. The difference between sunny days, light rain and others is obvious, and the difference between moderate rain, heavy rain and rainstorm decreases. On the basis of this, a method to identify the classification of rainfall using spectral width is proposed and validated, of which the accuracy rate can reach over 50%. In addition, the reasons that influence the identifying accuracy of the classification of rainfall by spectral width are also analyzed, and some improvement measures are put forward.
Lidar mefsurements of tropospheric aerosol in the frameworks of LRMC - 2017
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Nighttime sessions, based on the data of multifrequency sensing in Tomsk, make it possible to separate vertical layers with different scattering / absorbing properties and to estimate aerosol characteristics. Optical parameters – the lidar ratio and the Ångström exponent – are associated with aerosol advection at different altitudes of the troposphere. It is shown that the average radius of small particles and their contribution to the total concentration of particles are also combined with the backward trajectories of the air mass motion. The advection of air weaker affects the complex refractive index, especially its imaginary part.
Physics Of The Troposphere
Advanced methods for the study of regional climate-ecological systems under natural and manmade impacts
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Prospective issues of the organization of modeling technology for studying the climatic and ecological processes and solving the practical environmental problems are discussed. The combination of process models and observational data as well as the construction of numerical schemes is carried out within the framework of the variational principle with weak constraints. Some of the basic models, developed in the ICM and MG of the SB RAS for climate-ecological research, are presented.
Relation of integral moisture content of the atmosphere with elements of general circulation the atmosphere over the Eurasian continent
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In the work the comparative analysis of integrated moisture content of the atmospheres (W) between data of the reanalysis ERA-Interim and spectral solar photometry of the international global AERONET network over the Eurasian continent is resulted. For the 1979 to 2015 period, the correlation analysis between W and elements of the atmospheric general circulation (AGC) and also quasi-biennial oscillations (QBO) of zonal wind in the equatorial stratosphere is carried out.
Spatio-temporal distribution of air humidity over territory of the Siberian region
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The work presents the main patterns of spatio-temporal distribution of atmospheric total moisture over the Siberian region territory depending on the season and the physico-geographical conditions. The total moisture of the atmosphere was estimated on the basis of the model profiles of vertical distribution of the specific humidity up to an altitude of 30 km and with a large vertical resolution in the atmospheric boundary layer. The distribution of mean and extreme values of the total moisture was studied in the atmospheric boundary layer, in the troposphere and in the 0-30 km layer of the atmosphere for different physical and geographical regions of Siberia.
Long-term forecast of the lower cloudiness on the basis of the three-dimensional dynamic stochastic model
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The work presents the method of forecasting the amount of lower cloudiness with an advance time of one year based on the integration of the methods for ultra-long-term dynamic-stochastic forecasting of air temperature fields in the atmospheric boundary layer and the method for joint forecasting of meteorological fields for cases of related processes. Fields of air temperature and the amount of lower stratified cloudiness were considered as dependent fields. A statistical analysis of the forecasting quality of the lower stratiform cloudiness amount with an advance time of one year in the atmospheric boundary layer (up to 2000 m) is based on 47-years (from 1969 to 2015) 2-term observations of temperature and 8-time observations of the cloudiness of 6 upper-air stations in the Arctic regions of Siberia. It is shown that the mean square errors of the forecast do not exceed 3.0 balls, and the relative error of the forecast is in the range of 50−65% at all stations in the Arctic region of Siberia and at all heights of the atmospheric boundary layer, as well as in all seasons.
Atmospheric electric field in megacity aerosol pollution conditions
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We present the full-scale observational data of the near-ground electric field potential gradient in the megacity area and outside of its influence zone. The megapolis influence is manifested in an increase of signal amplitudes which is associated with the aerosol particles concentration difference. The obtained data analysis allows the technogenic aerosol megacity pollution level estimation. It is proposed to use the ratio of the averaged electric field potential gradient amplitudes at measurement sites as an integral pollution level indicator. Analytical expressions reflecting the integral pollution level indicator and the near-ground layer aerosol particle concentration relation are obtained.
Acoustic and electric field variations during strong frontal disturbances propagation
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Analysis of microbaric variations and variations of the electric field during atmosphere strong disturbances were carried out on the base of the data of instrumental registrations obtained in the geophysical observatory "Mikhnevo" of the Institute of Geospheres Dynamics of the Russian Academy of Sciences (IGD RAS). It is shown the hurricanes and storms are accompanied by high-amplitude variations of acoustic and electrical fields. Amplitudes of variations of these fields increase in a several hours before front arrival. This fact in the aggregate with meteorological parameters could be considered as a predicted indication of approaching hurricane or storms. It is determined that thundery front arrival is forestalled by long period electric field variations, internal gravity waves and increased acoustic impedance. Regularities, which were determined resulting from investigations, could be raise of forecast reliability and efficiency.
Infrasound noises of megapolis
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Given are results of analysis of data obtained by instrumental observations of infrasound vibrations performed in the area of Leninsky Avenue, Moscow. It was found that most intensive sources of infrasound are traffic lights and crossroads. Article illustrates difference in amplitude and spectral characteristics of infrasound depending on traffic flow regime. It contains date evidencing relation of infrasound noise with avenue load.
GFS model-based short-term fire weather forecasting
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The purpose of this study is to develop an algorithm for a 10-day fire weather forecast on the basis of the Global Forecast System, a global weather forecast model, and implement it in the proprietary-design information system for forecasting vegetation fire hazard by natural and anthropogenic conditions through the example of the Russian Far East. A relational weather database was designed to store and access the data of the National Centers for Environmental Prediction and the system metadata were integrated to the database.
PAHs transfer and intake to the water area of Lake Baikal during the summer forest fires in 2016
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We have analysed the data obtained during forest fires in the Irkutsk Region and Krasnoyarsk Krai in July 2016. The results show the polycyclic aromatic hydrocarbons(PAHs) intake to the water area of Lake Baikal. We have obtained the spatial distribution of the PAHs content in the surface aerosol and calculated their fluxes to the lake water surface. Using models of reverse trajectories and satellite photographs, we have traced the transfer of smoke trails from forest fires to the lake.
Influence of macrocyclic climate characteristics on the extreme precipitation in Irkutsk oblast
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The article considers the long-term dynamics of heavy rains and snowfalls on the territory of Irkutsk oblast for the period from 1950 to 2015. The share of extreme precipitations in the total amount of atmospheric precipitation is estimated. Seasonal features of changes in the frequency of extreme events, manifested in the insignificantly increased precipitation in autumn, typical for the Western synopticoclimatic region, and in winter increase within the Upper Lena and Southern regions of the investigated region are studied. The emerging trends may affect the seasonal changes in the hydrological regime in the watersheds of large rivers. The paper presents the analysis in the relationship between the extreme precipitation events and the macrocirculation mechanisms. Precipitation-forming elementary circulation mechanisms (ECMs) for Irkutsk oblast are identified. It was revealed that the maximum contribution to the extreme precipitation is made by ECM 13l (latitudinal western circulation), 13s (latitudinal western circulation and stationary position) and 12a (longitude northern).
Analysis of relation of Central England surface air temperature to the 11-year solar cycle
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On the base of 300-year data of the surface air temperature in Central England, with the help of cross-wavelet technique, we study the correlative relations of Central England temperature (CET) to the sunspot number and the index of the North Atlantic Oscillation (NAO). The cross-wavelet characteristics are the local correlation and local coherency. The local correlation of CET with the NAO index is positive and experiences a multidecadal modulation with a period of about 60 years. The local coherency and the local correlation between CET and the sunspot number on the frequency scale of the 11-year solar cycle experience modulation with a period of about 50 years. This modulation is likely associated with multidecadal variations of solar activity.
Analysis of transport of smoke aerosol in the atmosphere of the Baikal region by data of NAAPS and CALIPSO
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The paper presents the results of studies of air mass and smoke aerosol transport using the HYSPLIT, NAAPS models and data of remote sensing CALIPSO during the forest fires in 2016 in Baikal region. In June 2016 the homogeneous filling of the atmosphere by smoke aerosol over the Baikal region up to 2 km was observed. It is revealed that in the spectra of particle size distribution the large particles of the submicron aerosol fraction with a diameter exceeding 200 nm are observed, typical for smoke particles. The results of trajectories calculation have shown that in June influence of local fire on air quality in Ulan-Ude was observed under the general northwest transport of a smoke aerosol, in July downwind was mainly from the Irkutsk, Krasnoyarsk and the Yamalo-Nenets regions.
The polarizing and angular features of backscatter and radiation of the plowed soil
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The results of measurements of the angular dependences of radar backscatter coefficient and radio brightness temperature are presented. The measurements were carried out using a nanosecond radar with a carrier frequency of 9.95 GHz and a radiometer with a central frequency of 11.2 GHz installed on an automobile tower 16 m high. The test site is a potato field representing a regular structure in the form of parallel combs. The polarization features of the radar backscatter coefficient are determined. The experimental angular dependences are compared with the known models. The best accordance is marked with exponential models. Comparison of the angular dependences of the radio brightness temperature and the reflection coefficient shows their coincidence in the angular range of 40-90 degrees.
Variability of gas impurities in the ground atmosphere of South-Eastern Siberia
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The article presents the study of the spatial and timely concentration dynamics of the main polluting gas impurities (O3, SO2 and NOx) at three permanent sites of atmospheric monitoring in the south of Eastern Siberia. The monitoring measurements were carried out by passive, forced and direct methods that showed a good correlation varying between 0.7 and more. The results of the study have confirmed the previously determined trends of the annual course in the distribution of ozone in the ground atmosphere at the monitoring sites: maximum values of ozone concentration were in the spring (March-April), and minimal – in the autumn (September-October). Short-term fluctuations of the concentrations of the ground ozone in urban conditions depended on the content of anthropogenic gas impurities. The content of sulphur and nitrogen dioxides in the urban and rural areas was significantly affected by seasonal and interannual fluctuations depending on air temperature changing throughout the year (more in the winter, less in the summer) and on different years (more in cold years and less in warm years). At the Listvyanka site, increased concentration of the analyzed gases was in the warm season as well. It is caused by the high recreational load of the settlement as one of the largest touristic zones at Baikal in the Irkutsk Region.
Modern and projected changes of extreme summer precipitation in the Far East of Russia
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Variations of the frequency and intensity of extreme daily precipitation in summer in the southeast of the Far East Federal District of the Russian Federation, - in region with high risks of extreme seasonal floods, were studied for the period 1970- 2015 using data of 54 meteorological stations. Future changes for the period 2041-2060 were estimated using data of the global climate models HadGEM and MPI-ESM. It is shown that the observed and projected changes in frequency extreme daily precipitation events in summer are diverse and statistically insignificant when averaged for the whole study area. However, a growth of extreme daily precipitation intensity in the north of the study area and in the south of Sakhalin island is found in obserations for the recent period 2000-2015 being relative to 1970-1999. Such a tendency is projected by the middle of the 21st century according to the HadGEM and MPI-ESM models.
Tropospheric refraction of radio waves in the Baikal zone in different seasons of the year
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The possibility of using passive satellite sounding of the atmosphere in order to obtain data of vertical pressure distribution, temperature and relative humidity for modeling the altitude dependence of the refractive index of air is considered. Seasonal parameters of the exponential model of tropospheric refraction over the permanent points of GPS observations of the Baikal region (Irkutsk (IRKM), Ulan-Ude (ULAZ) and Badary, Tunka valley (BADG)) are obtained. Comparative calculations of the angles of refraction in different seasons of 2017 are performed. Calculations showed an insignificant difference in the refraction angles at the points of observation of the Baikal zone in order of magnitude from other climatic zones. In addition to high-precision geodesy, the GPS global positioning method can continuously determine the total zenith tropospheric delay (ZTD) which is related to the geometric parameters of refraction and has applications in radio physics and meteorology.
On the spectral albedo of the Earth as an indicator of the evolution of the climate and the planet
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The article is dedicated to the 65th anniversary of the FIRST in the world of the Keldysh Institute of Applied Mathematics ("Keldysh Institute"), created in the Academy of Sciences of the USSR, and its achievements in the Soviet "Lunar Program". In the "Keldysh Institute" was developed and implemented the information and mathematical support of the Soviet "Lunar Program". The experience of participation in this program is useful for applying the radiation transfer theory with the hyperspectral approach in space projects of remote sensing of the global climate system of the Earth by analogy with approaches to studying the planets of the solar system and Galaxies. Spectral observations are one of the important channels of the information in astronomy and astrophysics. Modeling and measuring the spectral albedo and brightness of the Earth as a planet in all spectral ranges from ultraviolet to millimeter radiation allows to obtain the important information about the properties of the sources and the mechanisms of their emission, and about the dynamics of that medium that absorbs, scatters and reflects electromagnetic waves. Simulation modeling can provide an answer to the global question: the evolution of the Earth as a planet is going in the direction closer to the model of Mars or Venus? FOR THE FIRST TIME, openly began to talk about the two most important mechanisms: the climate control and the climate management.
Objectively and manually identified characteristics of mid-latitude storms: a comparison for Siberian region
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A comprehensive intercomparison of midlatitude storm characteristics is presented. Extratropical storm characteristics were derived from 16 reanalysis-based objective automated algorithms for cyclone identification and tracking from the IMILAST project and from manual method based on an expert inspection of weather charts. The analysis was carried out for the Siberian region (50–80N, 60–110E) for two seasons (winter of 2007/08 and summer of 2008). Most of the automated algorithms show 1.5–3 times more cyclones and 3–5 times more cyclone tracks in the Siberian region compare to the manual method. The algorithms show a good agreement with the manual method for spatial distribution of cyclones and tracks number with spatial correlation coefficient varies around 0.8–0.9 in summer and around 0.7–0.9 in winter for most of the algorithms. Two ranking measures were used to evaluate similarity of objective algorithms with the manual method.
Tropospheric lapse rate and its changes in the Arctic from reanalysis data
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Estimates of the tropospheric lapse rate γ and an analysis of its connection with the surface air temperature Ts in high
latitudes of the Northern Hemisphere for summer and winter are performed using monthly-mean data from the ERAInterim
reanalysis (1979-2014). According to the reanalysis data the lapse rate values increase from 4.7 K/km near the
pole to 5.3 K/km in subpolar latitudes in winter and from 5.3 to 6.1 K/km in summer.
The estimates of dγ/dTs in interannual variability are found positive over the most part of the Arctic from reanalysis data.
At the same time, a negative correlation between γ and Ts was found for the Atlantic sector of the Arctic in winter and for
the central Arctic in summer. It is also noted regional peculiarities in the connection of lapse rate with Arctic oscillation
for winter and summer.
Eddy transport in the stably stratified planetary boundary layers and in the free atmosphere: upper troposphere and lower stratosphere
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Modeling turbulence is an important object of environmental sciences for describing an essential turbulent transport of heat and momentum in the boundary layer of the atmosphere. The many turbulence model used in the simulation of flows in the environment, based on the concept of eddy viscosity, and buoyancy effects are often included in the expression for the turbulent fluxes through empirical functions, based on the similarity theory of Monin-Obukhov, fair, strictly speaking, only in the surface layer. Furthermore, significant progress has been made in recent years in the development broader than standard hypothesis turbulent viscosity models for the eddy diffusivity momentum and heat, as result of the recording of differential equations for the Reynolds stresses and vector turbulent heat flux in a weaklyequilibrium approximation, which neglects advection and the diffusion of certain dimensionless quantities. Explicit algebraic model turbulent Reynolds stresses and heat flux vector for the planetary boundary layer is used in the stable atmospheric boundary layer, the upper troposphere, and the lower stratosphere. The present algebraic model of turbulence built on physical principles RANS (Reynolds Average Navier Stokes) approach for stratified turbulence uses three prognostic equations and shows correct reproduction of the main characteristics of the stably stratified boundary layer and evaluated the vertical eddy diffusivities of momentum and heat in the upper troposphere and the lower stratosphere.
Changes in the synoptic regime of Tomsk over the period of 1993-2016
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Here, we present the results of analysis of interannual variability and frequency of occurrence of atmospheric pressure systems and air masses of different types observed in the Tomsk region over the period from 1993 to 2016. The following types of APS were analyzed: cyclones, anticyclones, troughs, ridges, low-gradient baric fields, and contrast zones (areas of high-gradient baric filed between Zn and Azn). It is shown that the difference in the frequency of cyclones and anticyclones has significantly decreased over the past decade in the Tomsk region. In 2015 - 2016, their repeatability was almost the same. There is a tendency to decrease in the frequency of Arctic air mass occurrence and increase in subtropical air masses. During the past decade, tropical air masses have become to be observed more often in our region, especially in the spring.
Thermodynamic characteristics of a superstorm over the Black Sea
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The paper gives an analysis of a rare case of a powerful cyclone with an eye of the storm over the Black Sea. The development of the synoptic situationwas described, the thermodynamic parameters of the tropospherewere calculated, their dynamics wasanalyzed. The spatial distribution of moisture flows at a height of 3.5 km above the sea level is shown. The quantitative and spatial parameters of precipitation fields are estimated.
Classification of cloudiness from MODIS satellite data using regional statistical models for image texture and physical parameters of cloudiness during periods with snow cover
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Statistical models are presented of the image texture and cloudiness physical characteristics over various natural zones of the Russian Federation during periods of snow cover. These models are based on the determination of the distribution laws and estimation of their parameters, which describe the fluctuations in the values of the cloud characteristics. The results are discussed of a comparative analysis of statistical cloud models for various natural zones, as well as cloud models, averaged over them, over snow-covered territories and a snow-free underlying surface. A description is presented of the cloud classification algorithm based on the application of artificial neural network technology and fuzzy logic methods. The results are presented of recognition of 12 cloud types from MODIS satellite data for various natural zones during seasons with snow cover.
Georadar sensing of natural and artificial objects
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Several examples show the possibilities of wave diagnostics of natural and artificial objects by the method of GPR sensing. The frost mounds on the permafrost soils of the Eravna depression of the Vitim plateau, the ancient settlement of the Hunnish period near Nizhny Margintuy village of the Bichur district of the Buryatia Republic, and underground object in the courtyard of the Buryatia Republic Government House were investigated. GPR sensing allows to diagnosing natural and artificial objects quickly and cost-effectively.
Results of monitoring of the vertical carbon dioxide flux in the atmospheric surface layer of a background region of Western Siberia
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Vertical fluxs of carbon dioxide have been calculated with the use of data measured at a high measurement tower located at the territory of the Fonovaya Observatory of IAO SB RAS. The measurements have been carried out in the period from August 2015 to December 2018.
A link between June cold air outbreaks in Moscow and long range air transport
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A joint analysis of 10% of the lowest daily surface air temperatures (SAT) in Moscow in June 1971-2016 and corresponding 5-day backward trajectories of elementary air particles calculated using NOAA HYSPLIT_4 trajectory model was carried out. The most probable paths of cold outbreaks to Moscow have been revealed by the cluster analysis. The weighted trajectory method was used to localize the regions where the air masses bringing 10% of the lowest SAT anomalies in Moscow in June were transported from. The structure of large-scale atmospheric circulation associated with cold air outbreaks is revealed.
A link between sea ice concentration in Kara Sea in November and large scale atmospheric circulation
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Using satellite sea ice concentration (SIC) data in the Arctic, a composite SIC series was retrieved for the southwestern part of the Kara Sea in the region of Novaya Zemlya ice massif in November (the month of the end of intense marine navigation alone the Northern Sea Route) in 1978-2015. For all days of November 1978-2015 5-day backward trajectories arriving in the region of the Novaya Zemlya ice massif were calculated. The relationships between the variations of the SIC in the region of the Novaya Zemlya ice massif and long-range transport of air masses and the structure of large-scale atmospheric circulation are analyzed.
Potential sources of tropospheric nitrogen dioxide for Western Moscow Region, Russia
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A.M. Obukhov IAP of RAS performs regular measurements of the integral content of tropospheric nitrogen dioxide (NO2) by the MAX-DOAS method at the Zvenigorod Scientific Station (ZSS) since 2009. ZSS is located to the West from Moscow and is in background air mass of Central Russian about 80% of time, while polluted air of Moscow megacity cover it in about 20% of time. We calculate the fields of the average contribution of potential sources on the integral content of NO2 on ZSS using the concentration weighted trajectory (CWT) method. The NO2 measurements performed in cloudless sky were used for the analysis. Five-day backward trajectories of air particles arriving into the convective boundary layer of the atmosphere above ZSS were calculated using the NOAA HYSPLIT_4 trajectory model and the NCEP GDAS1.0 meteorological variables data fields. The differences of the fields of contribution of potential sources in warm (April-September) and cold (October-March) seasons of the year are analyzed.
Seasonal variability of range, distance, height and speed of air masses' transport in the surface layer to Moscow, Russia
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Using the NOAA HYSPLIT_4 trajectory model, 25500 10-day backward trajectories of air particles arriving into the Moscow air basin in 1948-2017 at an altitude of 100 m were modeled. For each trajectory, the path and the distance along the large circle, traversed by the air particle for 1, 3, 6 and 10 days before arrival in Moscow, are calculated. Mean paths and distances, mean velocities and air particle heights for the indicated trajectory durations in all seasons are calculated. The average seasonal "virtual" trajectories are calculated. Seasonal features of calculated parameters and average "virtual" trajectories are analyzed.
An influence of transboundary transport to the aerosols of the Southern Russian Far East by data of AERONET Ussuriysk site, Russia
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According to the data of the AERONET Ussuriysk site for 2004-2017 and modeling of 10-days backward trajectories of air particle using the NOAA HYSPLIT_4 trajectory model, the potential sources of four fractions of aerosols in the range of particle radii from 0.05 to 2.24 μm for the South of the Russian Far East are determined. The highest volume concentrations of aerosols in the specified particle size range in Ussuriysk are related to the transboundary transport of air masses from the PRC region near the Yellow Sea. The dynamics of the structure of large-scale atmospheric circulation is analyzed against the background of which the polluted air masses from this region are transported to the territory of the Russian Far East.
Regions of potential sources of precipitation in Moscow, Russia
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For all days of 1948-2017 the 10-day backward trajectories of air particles arriving in the convective (mixed) layer of the atmosphere over Moscow were calculated using the NOAA HYSPLIT_4 trajectory model and NCAE/NCAR Reanalysis. A total of 75000 backward trajectories were calculated. By the daily precipitation data of the Roshydromet weather station VDNKh (Moscow, Russia) the fields of the average contribution of potential sources to precipitation in Moscow were reconstructed for the warm (April-September) and the cold (October-March) seasons of the year using the PWT (precipitation weighted trajectory) method. Regions that contribute to different precipitation in Moscow in the warm and cold seasons were identified by the fields obtained. An attempt was made to reconstruct the field of the absolute contribution of the potential source to the total precipitation in Moscow in 1948-2017 in the cold and warm seasons.
Perspectives of monitoring of atmospheric-electric effects from volcanic eruptions in Kamchatka
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The informational value of atmospheric-electric effects for the monitoring of explosive volcanic eruptions of Kamchatka peninsula is shown and the plans to extend the registration sites are presented.
Lightning discharges distribution estimation over the Tomsk region in 2010-2015
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The northern part of the Tomsk region is a typical area of the boreal forest zone. Large forest resources occupy this territory. The forest fund is situated on the 90.5% of its entire area. There are 17 million hectares of forested area, including 9.9 million hectares covered by coniferous. 20-30% of forest fires in the Tomsk region caused by the lightning activity. Analysis of the thunderstorm activity in the context of fires is possible using Tomsk region as sample region. World Wide Lightning Location Network (WWLLN) data for 2010-2015 years are used in paper. This network registers lightning discharges throughout the year. The majority of thunderstorms occur over Tomsk region during the summer time. Data on lightning discharges during the period from May to September was selected for investigation. Data on spherics recorded by WWLLN contain the points: date, time, latitude, longitude, error and number of stations in which the electromagnetic pulse was recorded. Lightning discharge density maps were performed for cells 10×10 km.
Estimation of the subsea permafrost thickness in the Arctic Shelf
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The paper presents the results of mathematical modeling of the subsea permafrost dynamics and distribution on the East Arctic shelf. In this study the geographic distribution of the geothermal flow values was taken into account. Estimates of the permafrost thickness on the Laptev and the East Siberian seas shelf have been obtained. The depth of occurrence of the lower boundary of the frozen layer on the shelf was about 50-700 m. The position of the submarine permafrost upper boundary in the bottom sediments of the seas of the East Arctic substantially depends on the depth of the sea and the content of salts. It was found that the upper boundary of frozen rocks is located at a depth of 15-30 m below the seabed, depending on the shelf region. The increased heat flux leads to a significant decrease in the thickness of the submarine permafrost on the outer shelf and in the rift areas.
Malignant neoplasms on territories with different levels of magnetic fields of industrial frequency
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The incidence of malignant neoplasms in the territories with different levels of magnetic induction of the industrial frequency was investigated. The measurement of magnetic induction was performed using an automated complex including a laptop, a GPS receiver and magnetic induction testers oriented in accordance with the three components of the magnetic field vector. The measured data were subjected to spectral transformation with filtering harmonics of the industrial frequency, the magnetic induction module was calculated, which was displayed on the electromagnetic pollution map of the city. Data on cases of diseases for 2004–2012. were obtained from the cancer registry of the Tomsk Regional Oncology Center. The incidence was calculated in the territories with low (20–140 nT), medium (141–950 nT) and high (951–2511 nT) values of magnetic induction. An increase in the incidence of malignant tumors has been noted as the induction of the magnetic field produced by overhead power transmission lines increases. According to the Wilcoxon test, differences in morbidity are significant for incidence in areas with low and medium levels of magnetic induction at a significance level of p = 0.038; for morbidity in areas with low and high, medium and high levels of magnetic induction at a significance level of p = 0.007. The received epidemiological data demonstrate the role of magnetic fields of industrial frequency as a risk factor for occurrence of oncological diseases in the population.
Structure and long-term dynamics of surface atmosphere of Azov-Black Sea region on the base of self-organizing map analysis
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This paper uses an original approach for the typification of synoptic situations from re-analysis data over a long period of time. This approach includes the typification of surface atmospheric pressure and surface wind velocity fields over the Azov-Black Sea basin. The results of typification (structures) of surface atmospheric pressure and surface velocity are presented in the form of Kohonen self-organizing maps (SOM), and the percentage of time recurrence of the allocated structures is given. The relevance of the study is due to the need to study the physical patterns of development of various types of intense atmospheric circulation over the Azov-Black Sea basin and their relationship with the largescale atmospheric circulation on multi-annual scales.
The association between geomagnetic activity, meteorological variables, and cardiovascular characteristics of healthy people
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The results of a study of geomagnetic activity, meteorological parameters and cardiovascular activity of a group of healthy volunteers are presented. Variations of the northern, eastern and vertical components of the geomagnetic field, as well as meteorological parameters (temperature, humidity, atmospheric pressure) are considered as parameters of physical fields. Registration of physical fields is carried out in the synchronous monitoring mode in Tomsk, in the immediate vicinity of the place of residence of volunteers participating in the study. The indices of cardiovascular activity are calculated on the basis of simultaneous 24-hour monitoring of the electrocardiogram, arterial pressure and blood saturation of the subjects. The calculated correlation coefficients reflect different conjugation of the dynamics of the parameters studied in the work.
Variability of heart rhythm in young men in Yakutia depending on seasonal changes of atmospheric parameters
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A comparative analysis of the heart rate variability (HRV) parameters in healthy Yakut youths in different seasons of the year revealed high-sensitivity heart rate parameters: RMSSD is the root of the square sum of the differences in consecutive RR intervals, the power of the high frequency (HF) and low frequency (LF) components. These indicators characterize the features of vegetative regulation of the heart during seasonal fluctuations of meteorological factors in the conditions of the extreme climate of Yakutia. The study of the individual seasonal dynamics of HRV characteristics showed that youngest men show the dependence of the parameters on the time of the year. However, these dependencies are individual.
Variability of atmospheric integral water vapor content as dependent on synoptic processes
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The GPS-derived integral water vapor mesoscale structure is analyzed. In the paper measurements of a satellite navigation systems receiver’s network located near the Kazan city were used. It is shown that during the weather fronts the strong mesoscale perturbations appear in atmospheric integral water vapor fields. The intensity of mesoscale processes is correlated with the pressure and temperature variations.
Station for the comprehensive monitoring of the atmosphere at Fonovaya Observatory, West Siberia: current status and future needs
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Here, we briefly describe the station established by IAO SB RAS at Fonovaya Observatory to carry out continuous measurements of atmospheric composition and other parameters in West Siberia. Specifications of the instrumentation installed at the station, functioning modes of individual units comprising it, collection, transferring and storage of the measurement data are presented.
Measurement of meteorological quantities in the atmospheric boundary layer of the ultrasonic weather station AMK-03 on tethered balloon
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The results of measuring the vertical profiles of the main meteorological quantities in the atmospheric boundary layer to an altitude of 1000 m by the ultrasonic weather station AMK-03, placed on the suspension of a tethered balloon during its ascent and descent are presented in the article. Recommendations on the procedure for performing measurements using an ultrasonic weather station based on a tethered balloon are suggested.
Forecast map of the surface impedance of the seas of the Arctic ocean in winter time
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The technique of compiling predictive maps of the surface impedance of the ice-sea structure by maps of ice conditions for the Arctic Ocean in different seasons of the year is considered. A formula is proposed for transforming the spatial dependence of the ice thickness into the spatial dependence of the surface impedance at a fixed frequency of the VLFLF-MF ranges. Surface impedance calculations for various types of sea ice are presented. The novelty and practical significance of the work is that a prediction map of the surface impedance of the seas of the Arctic Ocean is created, which is necessary for the calculation of the spatial and energy characteristics and the selection of operating frequencies for high-latitude radio links and navigation on various radio propagation paths, including a surface electromagnetic wave (SEW).
Comparison of lidar and satellite measurements of vertical ozone distribution in the upper troposphere – stratosphere according to data for 2017
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Ozone was sensed with lidar at wavelength pairs 299/341 and 308/353 nm, allowing the vertical ozone stratification to be monitored within the upper troposphere – lower stratosphere, and within the stratosphere. The ozone lidar sensing, performed according to the method of differential absorption and scattering, is compared with data of IASI/MetOp and AURA satellites, as well as with the midlatitude Krueger model.
Estimation of the parameter of aerodynamic roughness of the underlying surface by the function of distribution of pollutant substances in the atmospheric boundary layer
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To solve the problems of meteorology, ecology, energy, a special interest is caused by the profile of wind speed and the coefficient of turbulent diffusion, which essentially depend on the terrain and the atmosphere condition. In the existing semiempirical models for the wind profile and turbulent diffusion, the aerodynamic effects, caused by the presence of inhomogeneities, are accounted by fitting parameters. Among them the most well-known parameter is the roughness of the underlying surface. Today the data given in the literature is about this parameter, measured for comparatively simple terrain and stable conditions of the atmosphere. The averaged values of the aerodynamic roughness parameters of the underlying surfaces that differ significantly in the degree of inhomogeneity were obtained in the work. Estimations were made using the pollutants distribution functions in the atmospheric boundary layer and an analytical solution of the diffusion-convective transport equation for a point high-altitude source. The distribution functions for coal-fired TPP emissions are measured by the moss-biomonitor method. Estimates obtained for a relatively homogeneous underlying surface are in good agreement with the data given in the literature.
Northern hemisphere temperature field structure in various time frames
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The paper researches Northern hemisphere surface temperature field structure based on the data of 818 meteorological stations for different time frames. Surface temperature is an integrated indicator of the global and regional climate change. Authors classified the stations by the degree of congruence in their multi-year temperature dynamics at various yearly intervals, corresponding to global climate trends. Temperature observational series were interpreted as phase modulated oscillations. The suggested classification is based on the hypothesis of geographical dependence in temperature signal phase modulation specifics. Congruence, namely temperature oscillation phasing in particular regions serves as a criteria for classification. The totality of climate-regulating influences on climate system forms a complex kind of phase modulation, which is though in some correspondence to those disturbances. We believe, that changes in synchronization modes of climatic and natural processes, is consequent to system transition into a new quality. The paper shows that with a global temperature growth regional temperature fields restructure and degree of congruence in temperature dynamics changes. Those changes are not uniform over different regions of the hemisphere. Temperature field congruence tends to decrease. The search for synchronization in non-linear chaotic systems, sensitive to initial conditions, might become a promising way of predicting models optimization.
Surface air temperature and pressure anomalies in the Northern Hemisphere during the 20th century: observations and reanalyses
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Observational and reanalyses data on surface air temperature and sea level pressure anomalies in the Northern Hemisphere during the 20th century are compared with a focus on the Arctic region. The evolution of temperature anomalies, the spatial distribution of temperature trends and the changes of the atmospheric centers of action (ACA) are analyzed. It is found that changes in temperature and pressure in the Northern Hemisphere extratropic latitudes throughout the 20th century have been more realistically reproduced by the European reanalyses, most successfully in CERA20C reanalysis. The NOAA20C reproduces the evolution and patterns of surface air temperature and sea level pressure anomalies changes significantly worse throughout the 20th century.
Thresholds of non-resonant generation in heterogeneous planar active media
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The studies have shown that films with different thicknesses, but practically identical transmittance values, give absolutely different results. This suggests that in addition to transmission, the generation characteristics are significantly affected by the thickness of the matrix being researched.
Modeling of water isotopes with model ECHAM6-wiso in nudging mode with reanalysis ERA5
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In order to validate the isotopic model of the general circulation of the atmosphere ECHAM6-wiso, modeling in nudging mode with data from reanalysis ERA5 was made. These model data were compared with experimental data on the isotope composition (δHDO and δH2 18O) of water vapor in atmospheric air for stations in Labytnangi and in Igarka created and maintained by the Climate and Environment Physics Laboratory INS UrFU and on Samoylov island, supported by the Trofimuk Institute of Petroleum Geology and Geophysics of SB RAS and the Alfred Wegener Institute (Germany), and with experimental data on the isotope composition of precipitation for the station in Labytnangi.
Influence of current atmospheric circulation on interannual oscillating variations in spatial distribution of lightning activity in North Asia
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The interannual related fluctuations of lightning activity in two vast regions located on the West Siberian Plain and in the Amur and Sungari River valley were attempted to be explained by the atmospheric circulation change in northern hemisphere defined by method of B.L. Dzerdzeevskii. The elementary circulation mechanisms facilitating high lightning activity in both regions simultaneously and separately were found.
Measurements of methane and carbon dioxide fluxes from wetland ecosystems of the Southern Taiga of West Siberia
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The ecosystem-atmosphere exchange of methane and carbon dioxide were measured during the summer campaigns 2014 – 2017 in Plotnikovo (N56°51’, E82°51’) on the wetland Flux-NIES automatic chamber complexes. Eleven vegetative groups on the bog’s surface and one lake site were taken in comparison. The objective of these particular measurements was to estimate the growing season carbon fluxes at sedge fen and on hollow-ridges nearby lake at Siberia ecosystems. The carbon balance of these ecosystems deeply relies on the peat wetness. Another objective was the integration of carbon fluxes from aquatic systems into terrestrial ones, in order to quantify and better understand the catchment scale carbon budget.
Electrokinetic effect on the shore line of Lake Baikal
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On the shoreline of the lake Baikal (near vil. Goryachinsk) established a relationship between the wave hydrodynamic and electrical processes. The physics of the phenomenon belongs to the class of electrokinetic effects. The filtrational natural electric field is associated with the movement of an incoming Baikal wave in porous sand. When fresh water moves in a porous medium (sand), an electric field is formed. The equipment and measurement procedure are considered. The results of measurements under various conditions of the wave process (storm, ordinary wave, calm weather) are presented. The novelty and practical significance of the work is that for the first time an electrokinetic effect was found on the shoreline of lake Baikal, which can be used to develop equipment for estimating the parameters of wave hydrodynamic processes in large freshwater reservoirs.
Detection of burnt areas in Yakutia on long-term NOAA satellites data (1985-2015)
Oleg A. Tomshin,
Vladimir S. Solovyev
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The results of processing the long-term AVHRR/NOAA data set (1985-2015) to map burnt areas using an adapted algorithm based on detection the changes in the NDVI vegetation index in the boreal forests of Yakutia (Eastern Siberia) are presented. Additional verification of the reliability of the identified burnt areas is made on the basis of expert evaluation. A good agreement of the detection results with MODIS data (R = 0.97) was found for the period 2001-2015. The emissions into the atmosphere of combustion products from forest fires for the period under review were estimated.
Investigation of Eastern Siberia vegetation index variations on long-term satellite data
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The study of NDVI variations and phenology dates of Eastern Siberia vegetation on NOAA satellite data (1982-2017) is carried out. Trend maps of seasonal NDVI (May-September) and maps of correlations NDVI with air temperature and precipitation were constructed. Area with the highest NDVI linear trend (10 – 15%) is located in the northern part of Yakutia. The increasing of NDVI seasonal trend is mainly due to significant increase of NDVI in May. Correlation between NDVI (in May) in the test site and air temperature is R=0.8. While the relationship between NDVI and precipitation is negligible. For 1982-2004 NDVI trend had near-zero values, but during 2004-2015 NDVI trend showed a significant increase about ~27%. The significant increase of air temperature (~30°C) during 2004-2015 is also observed in test site. Method “NDVI 0.3”1 based on NDVI threshold 0.3 was used to calculated the start and end of vegetation season in test site. In addition, BISE2 algorithm was used to reducing noise in daily NDVI time-series. Analysis of phenology variations during 1982-2017 showed: the SOS shifted by ~12 days earlier and EOS by ~4 days later. Thus, the growing season has increased. The average trend of growing season length is ~16 days. For same time, the mean values NDVI of growing season increased by ~10% and mean values NDVI of July by ~17%.
The influences of urban planning and green spaces on the level of traffic noise
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This paper describes the results of experimental study influences of urban planning and green spaces on the acoustic transport noises. The contribution of green spaces to the acoustic noise attenuation is shown.
Evaluation of the influence of sound and infrasound noise on simple human responses
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The paper presents the results of experimental studies of the effect of acoustic noise of the sound and infrasonic frequency bands on the auditory, visual, motor, tactile responses of a person, as well as on the time of making decisions. A method for estimating the time of human reactions was proposed, which was implemented by the authors as a software application for mobile devices. The obtained results unequivocally show an increase in the reaction time of all types under the influence of sound and infrasound noise even of a small level.
Analysis of processes of chemical transformation of impurities in the atmosphere of the industrial area
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Models for estimating the concentration fields of passive and chemically active impurities at large distances from the source have been developed from the data of the route observations. Their validation was made on the data of airborne observations of multicomponent pollution of the winter and summer boundary layer of the atmosphere of the Norilsk industrial region. For winter conditions, the results of estimating the fields of transformation of calcium and sulfur dioxide at distances of 60-100 km from sources of impurities are presented. On the basis of measurements of sulfur dioxide in the summer experiment, the correspondence of the processes of transverse expansion of the impurity flame to theoretical descriptions is shown and the direction of axial drift of the impurity is established.
Variability of air humidity characteristics over the territory of West Siberia using reanalysis data and their relationship with large-scale atmospheric circulation
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In the study statistical estimates of specific humidity and total water content of the atmosphere were calculated for the territory of West Siberia for cold and warm season over the period of 1979-2015 using reanalysis dataset. The research was carried out for the whole territory of West Siberia and separately for its northern and southern parts. It was obtained that air humidity changes correspond to temperature ones. It was also established that the influence of large-scale atmospheric circulation on the changes in humidity characteristics increases in the northern part of the region in cold season at the beginning of the XXI century.
Satellite monitoring of cloud cover in the areas of Yakutsk EAS array and TAIGA observatory at night-time
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We discuss a problem of cloud cover monitoring in the areas of Yakutsk EAS array and TAIGA observatory at nighttime during annual observations from October to April. It is shown, that utilization of data from instruments aboard Terra, Aqua, SNPP and NOAA-20 satellites, received by ground stations of Altai State University and processed up to level 2 (retrieval of geophysical parameters of atmosphere), provides an opportunity to carry out monitoring observations of cloud cover structure at night-time with high spatial resolution and frequency which is sufficient to make cloud correction of detector arrays readings.
Energy estimate of the Chelyabinsk meteoroid based on long-period oscillations of atmospheric pressure
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The paper deals with the assessment of the Chelyabinsk meteoroid energy based on long-period infrasonic waves in the atmosphere. A new technique is proposed, which utilizes the integral energy distribution in the power spectrum. The obtained results are in satisfactory agreement with the independent energy estimates.
Typisation of the chemical composition of the tropospheric aerosol of the south of Western Siberia by the air mass
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Synoptic analysis of the chemical composition of the inorganic matrix of tropospheric aerosol over the forest on the right bank of the southern part of the Novosibirsk reservoir (Karakan boron) is given. For the field of study of tropospheric aerosol in the 500-7000 m layer (above the Karakan boron), the chemical composition of the aerosol was classified during the aerosol sensing period from September 1997 to June 2017 for typical air masses in the region: continental arctic, continental moderate, and continental subtropical and tropical, united in one group.
Detecting embedded convection based on the surface atmospheric electric field data
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The paper suggests an approach for cumulonimbus clouds detection, including embedded convection, based on threshold values of surface atmospheric electric field potential gradient. On the example of IMCES SB RAS (Tomsk) measuringcomputation system, authors demonstrate the effectiveness of such approach implementation for real-time information obtaining on submerged convection in frontal cloud fields.
Simulation of smoke tracers transport in the Baikal region
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The work is focused on studying the features of local circulation formation and impurity transport processes in the Baikal region. To carry out the research, we use the basic numerical mesoscale model of the atmospheric dynamics and impurity transport in regions with complex relief, developed at the ICMMG SB RAS. On its basis, we created a special version of the model adapted to the climatic and orographic conditions of the region. The results of a numerical experiment on modeling the transport of a smoke tracer under the conditions of a summer meteorological scenario are presented.
Interannual variability and trend of total methane content in the atmosphere of Western Siberia in 2003-2017: results of AIRS/Aqua
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The interannual variability and rate of change of the total methane content in the atmosphere are studied in the Western Siberia zone (45°-65° N, 60°-90°E), which covers almost all the wetland complexes of the region, over the period 2003- 2017. The retrieval of the gas content was carried out using the regression model constructed by the authors and the data of the AIRS hyperspectrometer of the Aqua satellite. It was found that the total methane content has winter (January/February) and summer (July-September) peaks in each annual cycle for the period considered. It is shown that the content of methane in the atmosphere increased at a rate of ~ 3.3 ppb/year during this period.
Extreme heat in June 2012 and 2016 in Western Siberia in the light of long-term change of the macro-scale atmospheric circulation
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The temperature anomalies in early summer in Western Siberia, including the extreme heat of 2012 and 2016, are studied in terms of variations in large-scale atmospheric circulation (according to Northern Hemisphere Teleconnection Patterns). Estimates obtained using multiple stepwise regression show that the observed temperature changes from the mid-20th century, including long-term change, inter-annual variation and extremes, can be explained by the anomalies of several circulation modes. Macro-scale atmospheric circulation from the late 1980s - early 1990s can be characterized as a weakening of the westerly circulation, which is naturally accompanied by an increase in the frequency of blocking and temperature anomalies. The extreme manifestation of this мacro-scale circulation was catastrophic heat in Western Siberia in 2012 and 2016.
Anomalous behavior of the electric field of the atmosphere at the extremely low winter temperatures
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The analysis of the data of the coordinated measurements of atmospheric-electrical, meteorological and aerological values recorded during extremely low temperatures is presented. The issues of the relationship between the dehydration of the atmosphere and the evolution of the spectrum of variations of the electric field are considered when the temperature is lowered to extreme values and the fog is formed.
Local gradient magnetic fields of natural origin and their effects on the electrical activity of the human brain
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The paper presents the results of expedition studies of the dynamics of the parameters of electrical activity of the human brain in the gradient magnetic field of the geological fault zone. It is shown that these changes in the magnetic fields of natural origin influence the dynamics of the indices of the electrical activity of the human brain.
Variations of temperature profile of the atmosphere at the locations of Yakutsk EAS array and TAIGA observatory
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Variations of temperature profile of the atmosphere at the locations of Yakutsk EAS array and TAIGA observatory are investigated. Using data from hyperspectrometer AIRS onboard the Aqua satellite, a base of daily temperature profiles has been created for the period September, 2016 – December, 2017. Analysis of variations of the average temperature in the layer ~ 300 hPa above the observation level for the period from November 1st, 2016 to March 31st, 2017 is presented.
A numerical evaluation of the source identification algorithm for atmospheric chemistry model with the concentrations time series data
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The algorithm of source identification for atmospheric chemistry transformation models with the measurement data in the form of time series is tested numerical in the scenario with the second generation regional acid deposition model chemical mechanism. The algorithm is based on the sensitivity operator that is constructed from the ensemble of the adjoint equation solutions. This operator allows to apply algorithms for the solution of nonlinear operator equations for the solution of the inverse problem. The objective of the paper is to numerically evaluate the ability of the algorithm to solve the realistic inverse source problems with the mechanism.
Temperature regulations of frozen soils and mountain rocks in the district of Tiksi
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In connection with the growing interest in the development of the coast and the shelf of the Arctic Ocean, it seems relevant to study the frozen section of the Arctic coast by radio wave methods. The results of studying the geoelectric section of frozen soils and rocks of the Arctic coast in the vicinity of Tiksi by means of radio impedance and GPR sounding are presented. An experience of studying the frozen soils and rocks of northern Yakutia by means of a complex of radio physical methods of introscopy (radio wave diagnostics) of the underlying layered inhomogeneous medium (VLF-LF radio-impedance sounding and GPR) was summarized. The area of researches refers to the zone of permafrost. Series of long-term observations of total zenith tropospheric delay (ZTD) and its "wet" component (ZWD) for the permanent observation point TIXI are considered. A comparative analysis of direct measurements of the depth of thawing of cryolithozone soils, the results of ground-based radio wave soundings and GPS measurements has shown that it is possible in principle to determine the depth of thawing of cryolithozone soils using radio signals from the global navigation satellite system (GNSS).
Drift of psychophysiological parameters of the human body in conditions of gradient magnetic fields of natural origin
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The paper presents the results of studies of changes in psycho-physiological indicators (simple auditory motor and visual-motor reaction) of 2 volunteers in a zone with a modified magnetic field. It is established that in the presence of a gradient magnetic field, the volunteers have a longer response time to the visual and auditory stimuli.
Simulation of dynamic interphase exchange in a two-phase liquid-solid system
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Formulations of mathematical models and statements of problems for investigating the behavior of multiphase systems under natural conditions are discussed. In particular, here we consider the hydrodynamics of the liquid-solid system in the context of possible surges of gas hydrates from the bottom of Lake Baikal. The results of numerical experiments on the simulation of hydrodynamic processes in a system where the source of disturbances is the income of solid particles from the bottom of the lake are presented. Parametrizations of the interphase dynamic exchange are studied.
Numerical evaluation of the chemical data assimilation system in an urban scenario
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The efficiency of the variational chemical data assimilation algorithm is evaluated in a scenario for the city of Novosibirsk. In the algorithm the data assimilation is carried out quasi-independently on the different stages of the splitting scheme of the chemical transport model. RADM2 chemical reaction scheme is selected as the atmospheric chemistry reaction mechanism. Monitoring data is available in the limited number of the monitoring sites and for the limited number of species.
Variability of the main climate characteristics in Ekaterinburg during instrumental observations
Alexander F. Teterin,
Konstantin L. Antonov
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Ekaterinburg is the fourth most populated city in Russia. Meteorological observations commenced here in 1734. Regular meteorological observations are conducted since 1836. The paper presents the results of study of the main climate characteristics, namely mean monthly and annual air temperatures and wind speeds, monthly and annual precipitations. The period from 1881 to 2017 is considered. We studied the changes of climate parameters for the periods the same to those used in Applied Climate Handbook of the USSR. For the air temperatures, the period 1881-1937 and 1939-2017 was used, for atmospheric precipitations – 1891-1937 and 1939-2017, for wind speeds – 1936-1937 and 1939-2017. In long-term time series positive linear trend was revealed for average air temperatures and negative one for average wind speeds. There are no statistically significant trends in long-term dynamics of the atmospheric precipitation and Chromov's continentality indexes.
Investigation of the relation between snow cover and ozone concentration in the surface layer nearby Tomsk
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In this work on data of measurements of ozone near Tomsk communication of snow cover and change of ground concentration of ozone during 1990-2017 is investigated. It is revealed that it is possible to allocate 4 types of the seasonal course of ozone. Concentration growth which comes to an end with a spring maximum concerns the first. He is observed in 53,9% of cases. The second is characteristic the slow growth and surge in concentration after a snow descent (19,2%). The third differs in the neutral course at snow and sharp surge in concentration after his descent (15,4%). The neutral course without spring maximum (11,5%) is carried to the fourth type. Thus, at the end of the snow period the spring maximum of concentration is observed in 88,5% of cases. Differences in the seasonal courses in different years is explained by temperature dependence of photochemical generation of ozone in the atmosphere.
Dynamics of PM2,5 concentration in the surface layer of the Krasnoyarsk atmosphere in winter (2017-2018)
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Since December of 2017 the concentration of PM2,5 in the surface layer of the atmosphere has been continuously monitored at the posts of the Krasnoyarsk regional observation system. Analysis of the data showed that the content of PM2,5 in the air environment of the city of Krasnoyarsk affect first the period of unfavorable meteorological conditions (UMC) and secondly the height of the observation posts above the level of the Yenisei. It is established that the number of days when the concentration of suspended particles exceeds the MPCda is greater than the days of predicted UMC.
Classification of climate in the northern hemisphere by the envelope of temperature signals
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The authors developed the algorithm based on analytic signal theory, allowing grouping geophysical signals over various spatial and temporal scales. Surface temperature was selected as an integrated indicator of climate change. Algorithm can distinguish the climatic structures where multi-year temperature oscillations are congruent. To accomplish that, the information on temperature series amplitude temporal changes was used. Computing technology developed was applied to the data from 818 northern hemisphere meteorological stations over the period of 1955-2010. The classification for three correlation thresholds was obtained. Distinguished structures have strict geographical differentiation and defined by the highest synchronism level of temperature oscillations. Stations closest to each other spatially demonstrate the highest strength of relationship to typical class envelope.
Precipitation in the Lake Baikal basin associated with different patterns of atmospheric blocking over Western Siberia
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Since 1996, a low-water period has been observed in the Lake Baikal basin. The decrease of inflow to Lake Baikal is related to reduce of the summer discharge of the Selenga River, whose basin makes 83.4% of Lake Baikal catchment area. The decrease of river discharge is mainly due to a decrease of midsummer precipitations over the basin that occurs, preferentially, when the frontal system of the East Asian summer monsoon weakens. Some authors suggested that the reason for the East Asian summer monsoon variations is the features of atmospheric circulation at the mid- and high latitudes of Eurasia. In particular, atmospheric blockings can play an important role. We previously showed the features of formation of July rainfall in the Selenga River basin in different positions of blocking over Eurasia. We showed that precipitation tends to fall out in Mongolian part of the river basin when blocking is displaced from Western Siberia (WS) to Eastern Siberia (ES). Blocking in these cases may have a dipole configuration with anticyclonic part over Eastern Siberia and cyclonic part over Mongolia. In this work we continue to study blockings over Siberia and their relations with precipitation in the Selenga River basin in July. As a result we have formulated the following summaries regarding the relationship of WS-blocking and precipitation in the Selenga basin. 1. The maximum amount of precipitation is possible in case of complete blocking offset from West to East Siberia and formation of blocking over the eastern Siberia. 2. The amount of precipitation is not high if the blocking moves from the WS to the ES without formation of blocking over the eastern Siberia. 3. Precipitation in the basin does not fall out in the case of the blocking, which weakly shifts at the end of their life cycle. 4. There is a relationship between lifetime, intensity blocking and its movement over the WS. The stronger the blocking over the WS, the less it moves.
Regional structure of surface air temperature fluctuations in the Southern Urals
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In the article the analysis of monthly average near-surface air temperature for the period of 1940-2015 is presented, based on the observations on meteorological stations in the Southern Urals. For the study of the regional structure of the near-surface air temperatures a method of empirical orthogonal components (EOS). Correlation analysis has been performed of the defined EOC for the winter and summer seasons against indexes of the primary large-scale modes of natural climate variability of the Northern hemisphere.
On the conjugate problems of ecology, climate, evolution and remote sensing of the Earth
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Mathematician-philosopher, academician N.N. Moisees in the middle of the XX-th Century has moved from the geographical concept of "climate" and "environment" to global climate change and sustainable development of the planet and created the scientific basis for studies of the complex climate system of the Earth and the coevolution of nature and society. The scenario of "nuclear winter" is a clear illustration of this under the influence of environmental changes. We are talking about the conjugate problems of ecology, climate, remote sensing and global monitoring of the Earth from space and radiation forcing on the environment and global climate. Only through the conquest of space, development of space research and the international observing systems, as well as parallel supercomputing and big date appeared the prospect of solving such problems for the future of our planet - "Future of the Earth".
The total ozone field over the seismically active zones in the Middle East region in late 2017
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The total ozone anomalies in the lower stratosphere over the seismically active zones of Iraq and Iran at the end of 2017 were studied during the earthquake preparation, the main shock, and the aftershocks. The ozone anomalies are elongated and oriented approximately from west to east. Ozone contour lines were found to be considerably distorted over the peak zone on the day of the seismic event. The unstable TO field is likely to be caused by the disturbed geophysical environment in the seismically active regions of the Middle East, reflecting its response to emissions of gases through Earth’s crust fractures in the lowest atmospheric layer.
Physics Of The Middle And Upper Atmosphere
The causes of the large-scale ozone depletion over Antarctica in October 2015
V. V. Zuev
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The southern stratospheric polar vortex usually reaches its peak intensity in early September, and the size of the Antarctic ozone hole reaches its maximum in the second half of September. However, in 2015 the maximum values of the ozone hole area were observed in October and November and reached record values for these months for the last 39 years. An unusual increase in the ozone hole area in 2015 initially was explained by the influence of volcanic plume from the Calbuco eruption which occurred in April 2015 with a maximum plume altitude of 17 km. This conclusion is investigated in this study using the NOAA HYSPLIT trajectory model. It is shown that eruption plume from this Chilean volcano could not get inside the stratospheric polar vortex. The cause of the Antarctic ozone hole increase was an unusual strengthening of the polar vortex in October and November.
Meteor explosion over Northern Finland on November 16, 2017: ionospheric effects in the high-latitude lower ionosphere
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On November 16, 2017 at 16:40:22 UT over Northern Finland a powerful meteor explosion had occurred. Entry of the meteor was recorded by the all sky camera at the radio physical observatory Verkhnetulomsky (68.59°N, 31.75°E), and response of the high-latitude lower ionosphere to this explosion was recorded by the radar of the partial reflections at the radio physical observatory Tumanny (69.0°N, 35.7°E). After the explosion the considerable disturbances in the ordinary wave amplitude at the heights of 80-95 km have appeared. Using the temporal variations of the ordinary wave amplitude the periods corresponding to resonant atmospheric modes were identified: the acoustic cut-off period and the BruntVäisälä period, and also temperature of the atmosphere and sonic speed at the mesopause heights were calculated. It was suggested that the disturbances could be caused by the waves which had magnetohydrodynamic nature.
Vertical structure of temperature variations over European Russia in 2010 derived from MLS satellite observations
S. A. Sitnov,
I. I. Mokhov
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Using data from the MLS instrument (Aura satellite), the temperature variations at heights from the upper troposphere up to the lower thermosphere over the north of European Russia (60°-70°N, 40°-60°E) in 2010 are analyzed. The vertical structures of the changes in temperature associated with the annual- and semiannual oscillations, sudden stratospheric warming, summer atmospheric blocking event and 24-h thermal solar tides are presented.
Geophysical effects of solar flare on 6 September 2017
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Solar flare on September 6, 2017 was one of the strongest in recent years. The powerful X-ray and ultraviolet radiation of the flash caused significant effects in the upper and lower ionosphere, in the geomagnetic field and surface electric field. The interrelation and spatio-temporal distribution of geophysical disturbances induced up by the flare and their influence on the accuracy of positioning of global navigation satellite systems are shown.
Threats of the Agung volcano and the 55th anniversary of the opening of stratospheric aerosol layers by space Earth remote sensing
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In June 2018, 55 years have passed since the first scientific experiment in the history of world science was carried out by cosmonauts on manned "satellite-spacecraft ". This was the first scientific experiment on remote sensing of the Earth from space. Its results confirmed the existence of stratospheric aerosol layers formed due to powerful eruptions of volcanoes. In particular, it was justified that the discovered layers formed during the eruption of the Agung volcano on the Bali island in 1963. The eruptions of Agung volcano in 2017-2018 reminded of the pioneering achievements of Soviet cosmonauts and scientists in the exploration of outer space. Professor Georgy Vladimirovich Rosenberg theoretically substantiated this experiment and ensured the successful processing and objective analysis of space data. The publication is devoted to the 65th anniversary of the M.V.Keldysh Institute of Applied Mathematics of Russian Academy of Sciences, which provided the ballistic calculations of spacecraft "Vostok-5" and "Vostok-6" and the successful flight of Soviet cosmonauts Valery Fedorovich Bykovsky and Valentina Vladimirovna Nikolayeva- Tereshkova, the first female cosmonaut.
The effect of the 27-day solar cycle on the wave activity of the atmosphere calculated by a chemistry-climate model
Aleksandr N. Gruzdev,
Hauke Schmidt,
Guy P. Brasseur
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We analyze the effect of the 27-day solar cycle on characteristics of large-scale zonal wave harmonics of the geopotential in the northern hemisphere as simulated by the three-dimensional chemical-climatic model HAMMONIA. We found a noticeable correlation of the amplitude of winter planetary wave components in the northern hemisphere with the 27-day solar cycle. The strongest response is obtained for perturbations with wave number 1 in the middle and high latitudes. The amplitude of the corresponding variations of the geopotential height is ~300 m in the middle and upper stratosphere. The results presented point at possibility of the 27-day solar cycle effects on the large-scale wave activity in the winter atmosphere in the middle and polar latitudes of the northern hemisphere.
Substorm activity during the magnetic storms induced by the CIR and ICME events
Roman N. Boroyev
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In this work, the relation of substorm activity (AE, Kp) with the solar wind electric field during the magnetic storm induced by the CIR and ICME events is investigated. The analysis of average values of AE (АЕaver) and Kp (Kpaver) indices during the main phase of magnetic storm depending on the SW electric field has shown that for the CIR events, unlike the ICME events, the value of AEaver increases with the growth of average value of the electric field (Eswaver). The value of Kpaver correlates with the Eswaver only for the ICME events. When comparing time intervals during a recovery phase of two magnetic storms during which the values of solar wind electric fields are approximately equal to each other, it is found that AE index is more in that storm in which the solar wind velocity is higher.
Time behavior of total aerosol content in the stratosphere on the basis of data from Siberian Lidar Station in the period 2000-2016
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The time behavior of integrated aerosol backscattering coefficient (BAπ) in the stratosphere is presented for the entire 30-year period of its laser sensing at Siberian Lidar Station, Siberian Branch, Russian Academy of Sciences in Tomsk. In the time behavior of this parameter, we identified a quasi-homogeneous interval of 2000-2016, the analysis of which is presented in this report. The main processes, determining the aerosol loading of the mid-latitude stratosphere, are identified. Annual variations of stratospheric aerosol loading are presented in detail, which are used to compile the seasonal behavior of mid-latitude aerosol loading for this period.
Statistical analysis of time behavior of total aerosol content in the stratosphere on the basis of data from Siberian Lidar station in period 2000-2016
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We present the results of statistical analysis of time series of integrated (over stratosphere) aerosol backscattering coefficient, obtained at the Siberian Lidar Station in the period 2000-2016. The analysis had the following purposes: to identify the distribution functions of variations on the basis of histograms of experimental values; to determine the time intervals of interrelation in the total aerosol content on the basis of autocorrelation functions; to extract the periodic components in the time series with the use of procedures of fast Fourier transform.
Black carbon aerosol in stratosphere
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The brief review concerning sources, altitude distribution and dynamics of soot aerosol in stratosphere is presented. Possible experimental approaches for registration of soot particles and predictive methods for research of their dynamics in stratosphere are discussed.
Complex observations at the geophysical observatory "Klyuchi" during a strong geomagnetic storm in September 2017
A. Yu. Belinskaia,
V. L. Yanchukovskiy,
A. A. Kovalev,
et al.
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At the Geophysical Observatory "Klyuchi" (INGG SB RAS, Novosibirsk) complex geophysical observations are monitoring the variations of the flux of cosmic rays, the magnetic field of the Earth and the ionosphere. The report discusses the results of these observations during disturbances that arose in the near-Earth space after a series of events on the Sun in September 2017.
Short-term forecast of ionospheric parameters by oblique sounding data
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We present the application of the periodicity search technique for the solution of extrapolation problem for time series when the advance time of the forecast is 24 hours. This technique doesn't demand an equidistance of counting, has a little sensitive to missing data and can be used as the short-term forecast for several days ahead with background of 5 days. The considered technique has been used on the data obtained by chirp sounding network of ISTP SB RAS during the periods of strong and weak solar activity.
Method of estimation of aerosol thermal-physics properties
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Results of the theoretical analysis of effective density and heat conductivity for compact and fractal-like particles are presented. It is shown that estimations on the basis of Evans et al model (2008) predict reliable values of heat conductivities for fractal-like aggregates. The complete set of thermal-physics parameters necessary for theoretical description of fractal-like particles motion (drag force, photophoresis, thermophoresis) is discussed.
Trigger effect of the afterglow background medium after injection of the high speed plasma jet in the Fluxus and North Star experiments
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The report analyzes the optical data received by the MSX satellite during Fluxus and North Star active rocket experiments, conducted in 1997 and 1999 on the injection of high-speed plasma jets into the ionosphere. It has been demonstrated that 1 to1.5 seconds after injection, the irradiation of the background medium increases. The brightness of the luminescence is associated with the bursts of the flow of precipitated electrons, stimulated by injection of a plasma jet.
The impact of the Chelyabinsk bolide on the lower ionosphere
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The effect of infrasonic pulsed radiation from the Chelyabinsk bolide on the perturbations of the electron concentration in the D region of the Earth's ionosphere is considered. According to the electromagnetic measurements in the geophysical observatory Mikhnevo of the Institute of Geospheres Dynamics of Russian Academy of Science (IDG RAS), an estimate of the displacement of the reflection point of the SDV signals is obtained. Influence of infrasound radiation on the propagation of VLF signals on the Novosibirsk-Mikhnevo path is considered. The amplitude of the displacement of particles of the environment from infrasonic radiation is estimated. There is a good agreement between theoretical and experimental estimates.
Investigation of the influence of high-energy cosmic radiation on the parameters of the atmosphere
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In order to determine the influence of corpuscular solar and galactic fluxes on meteorological processes, a comparison was made of the time variation of cosmic radiation in the range of more than 3 MeV with the change in atmospheric precipitation and other atmospheric parameters for the period 2009-2017 obtained during observations at the Black Sea Hydrophysical Proving Ground (BSHPG) of Russian Academy of Sciences in Katsiveli settlement (Southern coast of Crimea). The results confirm the fact that the intensity of cosmic radiation has a significant effect on the formation of a number of hydrometeorological characteristics of the atmosphere (precipitation, air temperature, humidity, total and low clouds) at synoptic, seasonal and interannual scales of temporal variability.
Ionosphere modification and software-defined radio technology
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Under the active impact on the ionosphere, artificial inhomogeneities are formed. Their properties are investigated with incoherent scattering radars, aspect scattering and test wave methods etc. Scattering on ionospheric artificial inhomogeneities of a heating wave as a mean of energy injection into the inter-layer ionospheric waveguide is of interest. As a rule, in order to do that, scattering on ionospheric magneticallyoriented inhomogeneities is applied. The efficiency of energy injection into the ionospheric waveguide is determined by a scattered wave spatial distribution otherwise by a direction diagram of magnetically-oriented inhomogeneity set. To estimate their directional properties, SDR (Software-defined radio) technology will be used.
Developing a method for local correction of monthly average ionospheric model for current situation: basing on data from single-frequency GNSS receivers
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We develop an approach that uses simultaneous measurements of pseudo-distances from two GNSS navigation satellites made with a single-frequency receiver for an hour period to perform local correction of an ionospheric background model for current situation. Within the analytical component of a single-layer ionospheric model, we conduct a comparative analysis of the degree of influence of variations in the basic parameters of vertical electron density profile on pseudo-distance variations. We have established that critical frequency variations make the most significant contribution. Also important, however, is the consideration of electron density variations at heights well above the maximum. We present principles of the proposed correction method.
the numerical simulation of the 2017 september solar X-flares impact on the midlatitude lower ionosphere
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The progress in the physics and chemistry of the lower ionosphere depends on the verification of the numerical models on the experimental data. We establish the framework, that the lower ionosphere model can be considered as a valid one, only if the prediction for the VLF-LF radiowave propagation coincides with evidence both in amplitude and phase temporal dynamics. The extremely strong X-flares 06 and 10 September 2017 were chosen as a testbed for the empirical and theoretical models of the midlatitude lower ionosphere. Both models used GOES-15 X-ray flux measurements. Empirical model captures only the time moment of disturbance. Theoretical model captures the main feature in VLF response. We summarize the observed problems in simulation and prospective solutions as well.
Verification of the empirical lower ionosphere models on VLF observations at midlatitude Mikhnevo geophysical observatory
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The empirical models of the lower ionosphere are used for fast prediction of VLF-LF propagation properties, for the initialization in the inverse problem solvers and as a climatological testbed for new numerical models. We used two widely used empirical models and verify them on the experimental VLF data from Mikhnevo geophysical observatory for 2014 year. Numerical results were obtained by parabolic equation method. The presented results prove the severe limitations of the current empirical models. The main bottlenecks are formulated.
The requirement justification to the ionosphere models for the UHF-SHF radars
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We discuss the role and the usage of the ionosphere models in the improvement of UHF-SHF radar operation. The up-to-date empirical ionosphere models (International Reference Ionosphere (IRI), Fully Analytical Ionosphere Model (FAIM), Ne-Quick2) have too crude spatial and temporal resolution. The aforementioned models cannot describe the localized irregularities (like traveling ionospheric disturbances or waves) which, in turn, are regularly observed at the midlatitude high frequency chirp ionosonde. In the presence of such irregularities the additional range error in UHF range can exceed 1-2 km. The poorly known quasi-random nature of such irregularities leads us to the unique solution, namely, the rejecting of the laminar layered ionosphere in favor of the random electron density field. Such new probabilistic ionosphere model must be elaborated and verified on the experimental data.
Verification of the deterministic-probabilistic model of the D–region of the ionosphere by the radio physical data obtained in the geophysical observatory Mikhnevo
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The principles of the probabilistic-statistical modeling of the D–region of the ionosphere are described. The work is devoted to the calculation of electron concentration using deterministic-probabilistic modeling. In this work the electron concentration is calculated using the five-components system of the ionization-recombination cycle equations. Probability density functions (PDFs) of the input parameters of the model are used to solve the system. It was shown that theoretical PDFs of the Ne are in good agreement with two experimental databases of electron concentration. Results of the deterministic-probabilistic model are compared with the experimental VLF signals obtained in geophysical observatory Mikhnevo from the three transmitters in different heliogeophysical conditions.
Possible atmospheric manifestations of soot aggregate dynamics in the field of the atmospheric radiation
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New model describing the photophoretic motion of fractal-like soot aggregates is presented. The comparison with known experimental data has been performed and their good qualitative and quantitative agreement has been found. The calculated characteristics of the motion of fractal-like soot aggregates in the atmospheric radiation field are presented. The analysis of possible atmospheric manifestations of soot aggregate dynamics in the field of the atmospheric radiation predicts high transport possibilities of photophoresis at heights of the upper troposphere and middle stratosphere.
Modeling atomic oxygen nightglow during the strong magnetic storm on 20 November 2003
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Intensity variations in red line of atomic oxygen emission were analyzed using the ionosphere-plasmasphere coupling model. These variations were caused by precipitation of energetic electrons from the magnetosphere during the 20 November 2003 geomagnetic storm. The findings were compared to the optical data measured in Geophysical observatory of the ISTP SB RAS (520 N, 1030 E).
Investigation of the variability of stratospheric filling by background aerosol over Tomsk in 2017 based on lidar sounding
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Experimental data on the variability of the aerosol vertical-temporal structure obtained by the lidar complex of the Small Lidar Station of IAO SB RAS in 2017 are analyzed in this paper. An array of 61 total signals accumulated during separate nights were used as the primary information for analysis. The range of sounded altitude was from 10 to 50-60 km, the spatial resolution was 192m, the accumulation time of the total signal was 2 hours. According to the results of observations, as in previous years, a high aerosol content in the lower stratosphere was recorded in winter, as well as its practical absence in the warm season. In the upper stratosphere (30-50 km) there is no background aerosol throughout the year.
A regular stage of modernization of the lidar complex of a small lidar station at IAO SB RAS
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The lidar complex of the Small Lidar Station for high-altitude atmospheric sounding of the Institute of Atmospheric Optics SB RAS allows quick and regular obtaining the scattering ratio profiles up to an altitude of 70 km, temperature and density of the atmosphere in the altitude range of 10-70 km with a spatial resolution of 192 m. Measurements are carried out under conditions of a cloudless sky or, in extreme cases, broken clouds. To plan the measurement, the weather forecast is used and the latter are carried out when the forecast coincides with the real weather in the clear night time. Remote or automatic control of the lidar complex will improve the efficiency, quality (due to measurements with variable cloudiness) of the series of accumulated data and will increase the number of sessions of lidar sounding of the atmosphere.
Investigation of the dynamics of the vertical distribution of temperature in the stratosphere over Tomsk in 2017 based on lidar sounding
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One of the important applications of lidar technologies is the study of the thermal regime of the atmosphere. Such research at the Institute of Atmospheric Optics of the SB RAS has been launched since 1994 in the monitoring mode and is continuing at the present time. Particular attention is paid to the study of appearance of sudden disturbances in the middle stratosphere, caused by winter stratospheric warming (SW). The results obtained in this field of research can be found in reference 1. In this paper, we present investigations of the vertical temperature distribution over Tomsk in the disturbed and calm periods of 2017.
Results of the study of variability of the background aerosol content in the stratosphere over Tomsk based on the data of lidar measurements in 2011 – 2015
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The experimental results on the variability of the vertical-temporal structure of the stratospheric aerosol over Tomsk, obtained at the lidar complex of the Small Lidar Station of IAO of the SB RAS in the period 2011-2015 are presented. The characteristic peculiarity of this period, except of the second half of 2011, (appearance of the eruptive layers of the Grimsvotn volcano eruption over Tomsk) was practical absence of volcanic activity leading to the formation of stratospheric aerosol and its transfer to Tomsk, and therefore it became possible to study the behavior of the vertical structure of the background aerosol in the stratosphere during five years. According to the analysis of the lidar data obtained, a stable trend of aerosol filling of the lower stratosphere during the cold season with its maximum content in December-January and a practical absence of aerosol in the entire stratosphere layer during the warm season was revealed.
Investigations of thermal regime of the stratosphere over Tomsk in 2011 - 2015 based on the data of lidar sounding
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The studies of the temperature vertical distribution over Tomsk, carried out in the disturbed and calm periods of the year in 2012-2015 are presented in this paper. A number of peculiarities of the annual dynamics of the thermal regime of the stratosphere have been revealed on the basis of the accumulated experimental material. Thus, winter stratospheric warming occurs annually. During this period, two strong (major) warming were recorded in the winters of 2009/10 and 2012/13, in which the transfer of air masses in the upper atmosphere changed from western to eastern, and four weak (minor), they are winters 2011/10, 2012 / 11, 2014/13 and 2015/14. It has been shown during many years of observations that in most cases the vertical distribution of temperature over Western Siberian region during many years of observations is in good agreement with the model distribution of CIRA- 86.
The analysis of the solar spectra dynamics under x-ray superflares in September 2017 for the geophysical applications
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We present the results of the analysis for the GOES-15 and SDO satellites data under the extra strong solar X-class flares X9.3 September 06 2017 and X8.2 September 10 2017. It is shown that X9.3 flare was accompanied by the significant increasing of the UV flux and by the growth of the extremely hard X-ray part of the spectrum. The evidence from ionosondes, GPS receiver and Schumann resonance monitoring has shown different response to these neighbor flares. The flare classification based on the peak flux value is not sufficient for the geophysical applications. The interpretation of the ionosphere response requires the full spectrum analysis.
Ionization of the lower ionosphere during the x-ray solar flare on September 6, 2017
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In the study of the ionosphere total electron content (TEC), defined from the data of global navigation satellite systems, are widely used. It is assumed that the main contribution to the value of TEC is made by the F region. At the same time, the results of many studies show that during the X-ray flares the ionization of the D region can increase substantially, reaching values of 106 cm-3. In this paper, we analyze the changes in the parameters of the D region during an X-class flare on September 6, 2017. It is shown that a correct interpretation of the variations of TEC with powerful X-ray flares requires taking into account of the contribution to its ionization value of the lower ionosphere.
Solar flares effects in amplitude and phase variations of VLF radio station signals during September 2017
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Amplitude and phase variations of radio signals (11.9 kHz) of Khabarovsk and Krasnodar transmitters registered in Yakutsk and Tiksi during solar flares activity on September 04 – 10, 2017 are considered. The solar flares effects determined in a VLF signal phase delay during daytime propagation. The magnetic storm appeared on September 8 in amplitude and phase variations of VLF signals recorded in Yakutsk. The Khabarovsk signal amplitude decreased by 8 dB on September 8 (nighttime propagation). The phase delay of Krasnodar signal decreased by 70 degrees on September 8 (nighttime propagation) and by 40 degrees (daytime propagation) on September 9. For Khabarovsk – Tiksi propagation path the signal phase delay reduced by 35 degrees and the attenuation increased by 3.5 dB (19:40 UT) on September 10, 2017. For Krasnodar – Tiksi propagation path the signal phase delay decreased by 40 degrees (17-18 UT) on September 10, 2017. For Khabarovsk – Yakutsk VLF signal propagation path there is a phase delay decreasing by 6 degrees (daytime conditions: from 21 UT September 10 till 06UT September 11, 2017). According to the receiver in Yakutsk the phase delay of the Krasnodar signal decreased by 60 degrees on September 10 for a nighttime (17-18 UT) and the phase delay decreased by 50 degrees for daytime conditions on September 11. There is an attenuation increase of the Krasnodar signal on September 10 (from 17-18 UT). Such circumstances are caused by a sharp increase in the flux of high-energy solar protons on September 10-11.
Changes in temperature field under external impact considering humidity
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Based on NCEP/NCAR reanalysis data, we investigated changes in temperature spatial distribution during geomagnetic disturbance considering moisture content in the atmosphere. As a characteristic representing the external impact effectiveness, we suggested the impact index that accounts for both strength of geomagnetic disturbance and water vapor content in the atmospheric column. Similarity between changes in spatial structure of the external impact index and temperature is shown.
Internal gravity waves in the mesopause region according to the measurements at the Maimaga station
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The temperature of the mesopause region (87 km) is monitored at the Maimaga station (63.04° N, 129.51° E) using the Shamrock (Andor) spectrograph recording the OH band (3, 1). The temperature data obtained for the seasons from 2013 to 2017 are investigated. Standard temperature deviations σgw corresponding to internal gravity waves are obtained. The seasonal variation of the gravitational component of standard deviations of temperature σgw observed at Maimaga station almost coincides for three observation seasons except for the 2014-2015 season. In this observation season, σgw has lower values in winter than in other seasons. In addition, in the 2014-2015 season, average monthly temperatures exceed similar values in other seasons.
Influence of local time and power of solar x-ray flashes of M and X classes on the variation of frequency of first mode of Schumann resonance
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The paper presents the results of an analysis of the frequency variations of the first mode of the of Schumann resonator in the geophysical observatory Mikhnevo of the Institute of Geospheres Dynamics of Russian Academy of Science (IDG RAS) during solar X-ray flares of the M and X classes in 2011 - 2017. It is shown that the frequency variation depends not only on the flash class, but also on the magnetic field component and local time. It is suggested that this is due to the geometry of the path from the African Thunderstorm Activity Center.
The influence of geometric factors and data processing algorithms on the error of GNSS position in the GFO "MIHNEVO"
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The results of the analysis of the navigation task solution in the conditions of registration of the signals of the global navigation satellite systems GPS and GLONASS in the Mikhnevo GFO (the geophysical observatory) are presented. It is shown that in the classical algorithm, the choice of satellites from the observed constellation should be made not according to the criterion of elevation, but by the number of conditionality of the navigation task matrix. The use of adaptive iterative algorithms almost completely compensates geophysical perturbations while maintaining the twofrequency regime.
Appearance of light-scattering layers in the thermosphere of Kamchatka during the autumn of 2017
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The results of two-frequency lidar sounding of the atmosphere from the altitudes of 100-400 km are presented. The data were obtained in 2017 at a lidar site located in Kamchatka. One lidar channel is applied to investigate the aerosol formations in the middle atmosphere and to record the resonance scattering on excited ions of atomic nitrogen in the upper atmosphere. Nd:YAG laser operating on the wavelength of 532 nm is used in this channel. A dye laser with tunable frequency is applied in the second channel. The wavelength of 561.1 nm corresponds to the chosen dipole transition between the excited states of atomic oxygen. Defined light-scattering layers were discovered in the region of 200-400 km. They are caused by presence of excited states atomic oxygen and nitrogen ions. The possibility of reconstruction of excited ions Nh-profile and determination of precipitated electron fluxes by the lidar method are shown.
Investigation of sudden stratospheric warming by the Rayleigh lidar in Yakutsk
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The paper presents the comparative characteristics of sudden stratospheric warming (SSW) observed during the winter from 2005 to 2017 over the polygon of the EAS of SHICRA SB RAS (~ 60 km to the south from Yakutsk). A comparison of the lidar temperature data with measurements from the satellite "Aura" was made. The dependence of SSW on the phase of quasi-biennial oscillation (QBO) of the equatorial mean zonal wind and Nino 3.4 SST index .
Studying MLT temperature and composition during stratospheric warming events from spectrometric observations of OH (6-2) airglow emission at mid-latitudes
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We present the results of studying the temperature regime and the composition of the mid-latitude atmosphere at the mesopause heights during the periods of minor and final stratospheric warmings in February-March 2016. We used the data from the spectrometric observations of the hydroxyl emission at the Geophysical Observatory (Tory, 51.8°N, 103.1°E ) of the Institute of Solar-Terrestrial Physics (Irkutsk) and at Zvenigorod station (55.7º N, 36.8º E) of the A.M. Obukhov Institute of Atmospheric Physics (Moscow). The technique for calculating the concentrations of atomic oxygen and ozone at the OH emission layer using experimental data on the emission intensity and rotational temperature of the OH molecule, the photochemical model of OH radiation, and MSISE-E-90 model is described. It was found, that during the periods of analyzed stratospheric warmings significant, up to 250%, variations in the OH emission intensity and concentrations of atomic oxygen and ozone in the mesopause region were observed. The longitudional differences in the effects of the stratospheric warmings on the characteristics of the mesopause region were revealed.
Empirical model of the nitric oxide emission 5.3 μm in the upper atmosphere
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The systematization and the analysis of long-term data of satellite and rocket measurements of the 5.3-μm nitric oxide emission in the upper atmosphere were carried out. An analysis of photochemical processes leading to the producing of NO emission in the upper atmosphere is performed. Analytical relationships describing the seasonal and latitudinal variations in the intensity of the 5.3 μm NO emission, its altitude distribution, and the dependence on solar activity are obtained.
Sensor cluster for the atmospheric electric field and currents registration at the Geophysical Observatory "Mikhnevo"
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We study the surface electric field and the vertical atmosphere current at “Mikhnevo” geophysical observatory by means of a sensor cluster. The electric current sensor allows to disambiguate the displacement and conductive currents and to study their variations in sense of geophysical conditions. Data obtained under "fair weather" conditions and under significant perturbations are presented.
The variations in solar and geomagnetic activity modulate the dynamics of global military activity
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The report presents a retrospective analysis of the relationship between the annual values of the global index of Wheeler's military activity with the yearly values of Wolf Numbers (solar activity) and aa-index (geomagnetic activity). The analysis covered the XII-XVII centuries. Previously, such detailed comparisons for a given time interval were not carried out, primarily due to the lack of exact series of indexes, which were only relatively recently reconstructed at the Pulkovo Observatory. It is established that the maximum bursts of military activity fall on years with extremely low values of geomagnetic activity over the entire time interval, and vice versa. In turn, there was confirmed the earlier result about the coincidence of the Long-wave peaks of the Kondratyev economic conjuncture with the solar activity peaks: for 2 years before the maximum of Kondratieff waves, the Wheeler index takes the maximum value. Such heterogeneous dependencies and apparent contradictions with the classical results of A.L. Chizhevsky of economic and military activity on space weather require additional research. However, in any case it can be argued that, in addition to the well-known result of A.L. Chizhevsky about the confinement of revolutions and wars to maxima of solar activity, there is also an absolutely opposite class of events: bursts of military activity in years with extremely low geomagnetic and solar activity, and vice versa: the minimum of military events in years with extremely high values of geomagnetic and solar activity.
Perturbations of aerosol in the stratosphere over Tomsk in 2017
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Some peaks of aerosol scattering have been observed by the lidar in the stratosphere over Tomsk in August and December 2017. Using the results of air mass trajectory calculations and the satellite data on the air mass temperature along these trajectories, it have been concluded that the aerosol observed in August 2017 was of a volcanic origin (Shiveluch volcano, Kamchatka), and the aerosol observed in December 2017 represented the polar stratospheric clouds.
Synergy of terrestrial and satellite measurements for study of atmospheric aerosol in the Eurasian Economic Union’s countries
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The development of the scientific, methodological and technical basis for an integrated terrestrial and satellite monitoring of the atmosphere and the Earth's surface over the Eurasian continent is the goal of an international project carried out by the scientific organizations of Belarus, Russia, Mongolia and Vietnam with the support of the Eurasian Association for the Support of Scientific Research (EAPS). The report presents the results of testing the method of coordinated terrestrial and satellite, lidar and radiometric measurements to study altitude profiles of aerosol parameters in the areas of AERONET stations in the countries participating in the project. The data of the satellite lidar CALIOP and the solar radiometer were processed by the algorithms developed in the frame of combined lidar and radiometric sounding technique (LRS). Coordinated multiwavelength lidar measurements were carried out at remote sensing stations in IPNASB (Minsk, Belarus), IAO (Tomsk, Russia) and KRSU (Teplokluchenka, Kyrgyzstan) to validate the results of satellite data processing.
Empirical model of spatiotemporal distribution the critical frequency F2-layer of ionosphere
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The work is devoted to the analysis of long-term data series of the world network of ionospheric stations, and is aimed at studying the spectral composition and revealing long-term trends of the critical frequency F2 of the ionospheric layer. The accuracy of the description of the obtained model is calculated and the parameters of this model are given. The novelty of the work consists in applying the original method of constructing the model, and, accordingly, in creating a new qualitative-quantitative relationship of the input parameters and the results obtained from the empirical model. Also, the calculation of the parameters of the linear trend for each hour of local time at each latitude of the northern and southern hemisphere is given. The space-time distribution of the rate of change of the critical frequency foF2 on a global scale is presented.