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- Front Matter: Volume 9680
- Molecular Spectroscopy And Atmospheric Radiative Processes
- Optical Radiation Propagation In The Atmosphere And Ocean
- Optical Investigation Of Atmosphere And Ocean
- Atmospheric Physics And Climate
Front Matter: Volume 9680
Front Matter: Volume 9680
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This PDF file contains the front matter associated with SPIE Proceedings Volume 9680, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.
Molecular Spectroscopy And Atmospheric Radiative Processes
Continuum water vapor absorption in the 4000-8000 cm-1 region
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A line-by-line calculation of the continuum absorption coefficient with the wing line contour describing the absorption in different windows outside of the water vapor bands in the 4000–8000 cm-1 spectral region is presented. The continuum absorption calculated with the line wing contour characterizing the absorption in the 5800–6400 cm-1 window is shown to be close to the total absorption. Hence it follows that the absorption in the 5000–5500 cm-1 and 6900–7700 cm-1 bands is almost entirely due to metastable dimers and free complexes.
On the ck-correlation in the 9.6 μm O3 band
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The applicability of the ck-correlation approximation for certain spectral intervals in the 9.6 μm O3 band is examined. The problems of the optical thickness correlation and of the ck-correlation approximation assessment are discussed.
The D2O absorption spectra in SiO2 airgel pores: technical features of treatment
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The dynamic of the D2О in silica airgel absorption spectra in 4000…6000 cm-1 were recorded using Fourier Transform spectrometer FS-125M at room temperature and pressure of 23.4 mbar with spectral resolution of 0.03 cm-1. It is shown that the D2O dimers to make a significant contribution into absorption when nanopores filled with gas molecules is small. Is present a detailed description of techniques for processing the primary experimental data.
Calculation of the water vapor line intensities for rotational transitions between high-excited energy levels
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The intensities of water vapor in the range of pure rotational transitions were calculated up to high quantum numbers (Jmax ~ 30 and Ka max ~ 25). The diagonalization of the effective rotational Hamiltonian, approximated by Pade-Borel method, is applied to obtain the eigenvectors. The centrifugal distortion perturbations in line intensities were taken into account by the traditional equations for matrix elements of the transformed dipole moment, including eight parameters, and previously developed by authors Pade approximant. Moreover, to conduct the calculations, the rotational wavefunctions of the symmetric rotor molecule were applied. The results were compared with the known theoretical data.
Spectral structure of the water vapour continuum absorption in 2.7 and 6.25 micron bands
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For the first time, the low-temperature (from -9 to 15 ° C) Fourier Transform Spectroscopy laboratory measurements of the pure water vapor absorption spectra are performed in the near-infrared spectral region, and self-continuum absorption is retrieved within 1600 cm-1 (6.25 μm) and 3600 cm-1 (2.7μm) absorption bands. The proportion of true-bound and quasi-bound water dimers in the equilibrium water vapor is derived by fitting their model spectra to the spectral features of the retrieved continuum. The results are in reasonable agreement with statistical calculations and support the idea of complimentary contribution stable and metastable dimers to the spectral structure of water vapor continuum within absorption bands.
Estimation of self-broadening for SO2 lines
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Estimations of self-broadening coefficients of the main isotopic modification of SO2 are performed. The result is presented as a formulae describing the dependence of self-broadening coefficients on rotational quantum numbers of the lower state of a transition. The comparisons of our estimated self-broadening coefficients values with those from the HITRAN database are presented.
High-temperature spectral dependences of 14N16O2 in the range of pure rotational and vibrational-rotational transitions
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The modelled absorption coefficients of 14N16O2 are performed in the range of pure rotational and vibrational-rotational transitions at T = 300 K and T = 1000 K temperatures. The calculations were carried out on the basis of the developed by authors high-temperature database of NO2 spectral line parameters and database HITRAN2012. The dipole moment function parameters of NO2 up to the second order inclusive were also determined.
A systematization of spectral data on the methanol molecule
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Problems underlying a systematization of spectral data on the methanol molecule are formulated. Data on the energy levels and vacuum wavenumbers acquired from the published literature are presented in the form of information sources imported into the W@DIS information system. Sets of quantum numbers and labels used to describe the CH3OH molecular states are analyzed. The set of labels is different from universally accepted sets. A system of importing the data sources into W@DIS is outlined. The structure of databases characterizing transitions in an isolated CH3OH molecule is introduced and a digital library of the relevant published literature is discussed. A brief description is given of an imported data quality analysis and representation of the results obtained in the form of ontologies for subsequent computer processing.
Linewidths and temperature exponents of CH3CN-N2
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Calculations of nitrogen-broadening coefficients and their temperature exponents for methyl cyanide lines at the room temperature using semi-empirical method are presented. They were performed for wide ranges of rotational quantum numbers J and K requested for atmospheric applications: J from 0 till 70 and K from 0 till 20. The temperature exponents were calculated for every mentioned line. Extensive line lists are provided for the Earth and Titan atmosphere temperature ranges.
Dependence of H2O-N2 broadening coefficients on the vibrational quantum numbers
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Line broadening in the case of H2O-N2 colliding system only slightly depend on vibrational quantum indices. The largest difference in the broadening coefficients of different bands is as small as several percent. Usually the halfwidths obtained for only one band is extrapolated to other vibrational bands. Indeed, in the case of low-lying states the vibrational amplitudes are usually small in comparison to the equilibrium distances between the atoms. However, for transitions to highly excited states, the intra-molecular motion cannot be treated as small amplitude vibrations, and as a consequence, corrections due to the intra-molecular interactions are large. The vibrational dependence of the line widths was studied by a high resolution Fourier-transform spectrometer IFS-125M. Line-broadening and line-shifting coefficients derived from the fitting were compared to calculated data.
H2O self-broadening coefficients of rotation-vibration lines in the 15 500 - 16 000 cm-1 region
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Line broadening coefficients of the Н2О-Н2О system were investigated in the region 15500 – 16000 cm-1 using a high resolution Fourier-transform spectrometer IFS-125M. The White type multipass absorption cell with a basic length of 60 cm was used. Least-square-fitting algorithm WXSPE was used to retrieve of the spectroscopic parameters from measured spectral data set. Calculations of self-broadening are performed using a semi-empirical approach. This method is further developed by using anharmonic wavefunctions in the estimates of line profiles. This approach explicitly takes into account all scattering channels induced by collisions. Calculated data are in a good agreement with the measured ones.
Investigation of interaction of carbon dioxide with aerogel's nanopores
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The absorption spectrum of 2 0 0 12 – 0 0 0 01 band of carbon dioxide, confined in 20 nm nanopores of silica aerogel, was measured with help of a Bruker IFS 125 HR Fourier transform spectrometer at room temperature and a spectral resolution of 0.01 cm-1. The obtained dependence of spectral line half-width values on rotational quantum numbers was studied and compared with data available in the literature.
He-broadening and shift coefficients of water vapor lines in infrared spectral region
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The water vapor line broadening and shift coefficients in the ν1+ν2, ν2+ν3, ν1+ν3, 2ν3, 2ν1, 2ν2+ν3, and ν1+2ν2 vibrational bands induced by helium pressure were measured using a Bruker IFS 125HR spectrometer. The vibrational bands 2ν3 and ν1+2ν2 were investigated for the first time. The interaction potential used in the calculations of broadening and shift coefficients was chosen as the sum of pair potentials, which were modeled by the Lennard-Jones (6-12) potentials. The vibrational and rotational contributions to this potential were obtained by use of the intermolecular potential parameters and intramolecular parameters of H2O molecule. The calculated values of the broadening and shift coefficients were compared with the experimental data.
Investigation of porous structure of SiO2/Al2O3 aerogel by the method of low-temperature adsorption of nitrogen and high-resolution spectroscopy
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The paper presents results of evaluation of size of aerogel pores, synthesized by the sol-gel method without the use of supercritical drying. The aerogel framework was formed by alumina nanosheets and silica spherical particles. Pore size distribution was bimodal with the maxima at 5.5 nm and 77 nm.
Light-emitting-diode Fourier-Transform spectroscopy of HD16O between 11200–and 12400 cm-1
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The absorption spectrum of monodeuterated water, HDO has been investigated between 11200 and 12400 cm-1. The spectrum has been recorded using IFS-125M interferometer with spectral resolution of 0.05 cm-1. For measurements White’s-type cell were used. The bright light emitting diode (LED) EDEI-1LS3-R was applied as a source of radiation. Signal to noise ratio was about 104. The spectral line parameters - line positions, intensities and half-widths were obtained by least square fitting. As a result of the spectrum analysis the line list containing more than 1500 lines was created. The spectral line parameters have been compared with the previous measured and calculated data.
To the selection of heat flux parameterization models at the water-air interface for the study of the spring thermal bar in a deep lake
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The paper is devoted to the comparative analysis of the parameterization models of latent and sensible heat fluxes, longwave radiation calculated on the basis of the papers of Goudsmit G.-H. et al. (2002), Hodges B. (1998), Ji Zh.-G. (2008) with the use of atmospheric data of the meteorological station of City of Kamloops (Canada) within the period from 01.04.2001 to 10.05.2001. Numerical analysis of the distribution of spring thermal bar in Kamloops Lake was carried out with mathematical simulation methods.
Verification of H2O lines from the HITRAN database for remote sensing of the water vapour isotopic composition
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The quality of the spectroscopic line parameters from the HITRAN Database for remote sensing of the water vapour isotopic composition of the atmosphere is widely discussed. In this research we show that the HITRAN-2008 data for H2O isotopologues in the near infrared spectral range (4000-6400 cm-1) is reasonably good. The HITRAN data was tested with independent calculation (ab initio et al.). For the evaluation we've used two following criteria: a quality of the fitting of atmospheric spectra measured at the Ural Atmospheric Station (UAS, Kourovka) with the high-resolution Fourier-transform infrared spectrometer and an agreement between the retrieved HDO/H2O relative concentration ratios in the atmospheric column and the results of the simulation of the isotopic general circulation model ECHAM5-wiso (validated for Kourovka region).
Architecture of scalability file system for meteorological observation data storing
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The approach allows to organize distributed storage of large amounts of diverse data in order to further their parallel processing in high performance cluster systems for problems of climatic processes analysis and forecasting. For different classes of data was used the practice of using meta descriptions - like formalism associated with certain categories of resources. Development of a metadata component was made based on an analysis of data of surface meteorological observations, atmosphere vertical sounding, atmosphere wind sounding, weather radar observing, observations from satellites and others. A common set of metadata components was formed for their general description. The structure and content of the main components of a generalized meta descriptions are presented in detail on the example of reporting meteorological observations from land and sea stations.
Simulation of the atmospheric transfer of the solar radiation in water vapor absorption bands
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The atmospheric solar spectra are calculated using different spectroscopic databases of H2O absorption line parameters in the temperature and humidity range observed in the mid-latitudes. A comparison of the simulated spectra and measured high-resolution atmospheric spectra in the near-infrared water vapor bands, is carried out. It is shown that the values of H2O atmospheric column, retrieved using different modern spectroscopic databases may vary by more than 3%.
Highly excited vibrational states of 18O3 as a test of the ozone potential energy surface
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This work is a part of our systematic investigation of the very weak absorption spectra of 16O3 and 18O3 by high sensitivity Cavity Ring Down Spectroscopy between 5850 and 7920 cm-1. In total, 29 vibrational bands of 16O3 and 24 bands of 18O3 have been assigned in this range. Here we present the recent results of analyses of highly excited states of 18O3 ozone, located near the dissociation energy (D0~8560 cm-1). The comparison of the vibrational band centers obtained from the analysis with the predictions based on the potential energy surface (PES) suggests that the hypothesis of the “reef structure” at the ozone transition state towards the dissociation is not confirmed by spectroscopic observations. In this work, we focus on the comparison between theoretical and experimental values of the 18O3 vibrational levels near the dissociation limit.
Simulation of the LMR spectra in the 0-1 band of NO molecule
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The results of the LMR spectra calculation in the 0-1 band of the NO molecule are presented. For the simulation of the spectra in a strong magnetic field the special numerical model was developed. This model allows one to calculate the dependence of Zeeman splitting of ro-vibrational lines of the NO molecule on the intensity of a strong magnetic field. The analysis of temporal behavior of the absorption coefficients of CO laser radiation on thirteen lines in the variable magnetic field was done.
Development of an Internet accessible software: optics and spectroscopy of gas-aerosol media
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A description of an Internet accessible software «Optics and spectroscopy of gas-aerosol media» is represented. The new software is focused on research in the field of direct and inverse problems of optics and spectroscopy of gas-aerosol media.
Study (301)-(000) D2О band in 10200 - 10450 cm-1 spectral region
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Measurements of D2O absorption spectra in the visible spectral region near 0.98 μm are performed using FT-spectrometer IFS-125M and Light-emitting diode (LED) as source of radiation. Water vapor spectrum has been obtained by averaging over 17136 scans recorded at 24 m optical path length, temperature 24 С and pressure of sample 27 mBar. Due to strong emission of LED source it was possible to achieve signal-to-noise ratio about 104 and to record weak lines with intensities of 6 10-27 cm/molecule. Comparisons with results of early works are made.
Optical Radiation Propagation In The Atmosphere And Ocean
Orbital angular momentum of laser beam in the turbulent medium: asymptotic estimates and numerical simulation
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Numerical simulation and analytical calculations of the variance of fluctuations of the total orbital angular momentum (OAM) of Laguerre—Gaussian and Gaussian laser beams propagating in the randomly inhomogeneous atmosphere have been carried out. It is shown that as such beams propagate in the weakly turbulent atmosphere, the relative variance of OAM fluctuations remains much smaller than the relative variance of intensity fluctuations.
Approximations of the synoptic spectra of atmospheric turbulence by sums of spectra of coherent structures
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It is shown that the known experimental synoptic spectra of the atmospheric turbulence (spectrum of Van der Hoven, 1957; spectrum of Kolesnikova, Monin, 1965) represent the sum of the solitary spectra of coherent structures with various sizes (with variety outer scales).
Turbulence structure over inhomogeneous heated surface
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Structure of air turbulent motion inside closed volume (without exchange of internal and external medium through the borders) over inhomogeneous heated underlying surface had been studied by numerical solving of boundary value problems for hydrodynamics equations (Navier–Stokes). The solitary large vortices (coherent structures, topological solitons) whose decay generates the coherent turbulence are observed over homogeneous heated surface. Inhomogeneous heated surface leads to the appearance of Kolmogorov (incoherent) turbulence. The simulations confirm our previously experimentally (inside the dome rooms of astronomical telescopes) and theoretically stated conclusion that the mixing of coherent structures of different close-by sizes and different frequencies of major vortices results in the non-coherent Kolmogorov turbulence.
About temporary autocorrelation function of fluctuations of the scattered radiation of the focused laser beam (0.63 mm) in the surface atmosphere in rain, drizzle and fog
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Measured temporal autocorrelation function the fluctuations of the scattered radiation of the focused laser beam (0.63 μm) in the surface atmosphere in rain, drizzle and fog on the highway with a length of 130 m. Found that the time correlation of the fluctuations of the scattered radiation of the focused laser beam in the rain and drizzle decreases with increasing perpendicular component to the path the wind speed is at close to atmospheric conditions (with close values of optical depth and particle size of atmospheric precipitation). The time correlation in the fog more, than the time correlation in the drizzle. It is an order of magnitude or more greater than in the rain.
Photosynthetically available radiation on surface of the Black Sea based on ocean color data
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Long term (1996 – 2014) averaged annual dynamics of daily photosynthetically available radiation (PAR) incident on the surface of the Black Sea have been estimated for different degree of sky coverage by the cloudiness. To this aim PAR standard product of color scanners (OCTS, SeaWiFS, MODIS-Aqua/Terra) has been processed. The processing method was based on the assumption that temporal PAR dynamics over one day corresponded to PAR spatial variability in the Black Sea area scanned by satellite instruments during one overpass. PAR data could be applied for different researches of the Black Sea ecosystem, which is related to photo-physiological processes.
Phase reconstruction strategies in phase-locking system based on multi-aperture wave front sensors
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System of coherent beam combining with multi-aperture wave front sensor based on the Gerchberg-Saxton algorithm is considered. Different system architectures and reduction methods based on block algorithms are proposed. The system is simulated numerically for a different number of phased channels.
Influence of the spatial shape of nonspherical symmetric dielectric microparticles on morphology of photonic jets
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The results of numerical modeling of the near-field scattering of the light wave (photonic (nano)jet - PNJ) on the composite particles, representing a truncated circular cone with attached hemispheres are presented. For the first time it is shown that the combination of spherical and conical light focusing by composite particles leads to the formation of highly localized photonic jets with peak intensity being considerable higher than that for isolated microaxicons of the same cross-section.
Modeling of microphysical characteristics for fractal-like soot aggregates: the effective heat conductivity
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Results of theoretical estimations of effective heat conductivity for fractal-like soot aggregates on the basis of Evans et al. (2008) theory are presented. It is shown that these estimations give an adequate values of this parameter essentially important for calculations of characteristics of photophoretic motion of soot aggregates. Comparison of the developed theory for fractal-like particles photophoresis with experimental data of Karasev et al. (2004) demonstrates high efficiency of the offered approach.
Characteristics of photonic nanojets from dielectric microparticles of various spatial shapes
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The near field of scattering of an optical wave (zone of photonic jet (PhJ)) at radially symmetric nonabsorbing micronsized dielectric particles is numerically simulated with an emphasis at the study of size and amplitude parameters of photonic jets from quartz microparticles of various spatial shape and orientation. Photonic jets from hemispheres are shown to have the long length, but relatively low intensity. The use of conical particles of a certain shape gives a record increase of the PhJ length up to two tens of wavelengths of the incident radiation (at the fixed intensity level) at the preserved subwavelength transverse dimension of the photonic jet.
Image processing of cloud fields based on satellite data
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The method is considered of determining the direction of movement of cloud fields based on a series of images of clouds received from open sources.
Micropulse lidar for detection of backscatter amplification in the turbulent atmosphere
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The design of a two-channel lidar with afocal transceiving telescope receiving the backscattered radiation at the axis of the probing beam and at some distance from the axis is described. The lidar with this design can detect the atmospheric backscatter amplification caused by turbulent fluctuations of the refractive index of air due to the correlation of the probing and scattered radiation. The power ratio of echo signals recorded in two different channels gives the value (coefficient) of backscatter amplification. The developed micropulse two-channel lidar can conduct unattended continuous measurements for a long time.
Lidar measurements of backscatter amplification in a surface atmosphere
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The results of long-term continuous measurements of the atmospheric backscattering amplification on an atmospheric surface path 2 km long with a two-channel micropulse lidar based on waveguide laser are presented. It is shown that the backscatter amplification coefficient has the pronounced diurnal behavior. In the day and night time, the atmospheric backscattering amplification is maximal and the amplification coefficient can exceed two. The amplification is low or absent in the morning and evening hours at the neutral temperature stratification in the atmospheric surface layer. The backscattering amplification coefficient increases with an increase of the structure constant of the refractive index of air, as well as with an increase of random wander of optical image of the probing laser beam spot at the distance 2 km from the lidar.
Estimate of effect of initial field distribution using streamlines of the average Poynting vector on the change of the effective spot size of the laser beam propagating in the turbulent atmosphere
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The results of studies of the effect of the initial distribution of the laser beam to change its effective spot size in a turbulent atmosphere are presented. Investigations were carried out for axially symmetric light beams using the method of streamlines of the averaged Poynting vector. The dependence on a shape of the initial intensity distribution of effective spot size of the beam at the receiving plane is investigated as in presence as in absence of phase dislocations in the initial field distribution. It has been shown that it is possible to choose the values of the parameters of ring and vortex beams and that the magnitude of the effective spot size in the plane of the reception will be lower than for a Gaussian beam with the same value of initial effective spot size in the propagation of laser radiation in a turbulent atmosphere.
Numerical investigation of energy density fluctuation of pulsed Laguerre-Gaussian beams
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The propagation of broadband femtosecond pulsed Laguerre-Gaussian beams in a turbulent atmosphere was studied. Based on the numerical solution of the parabolic wave equation for the complex spectral amplitude of the wave field by splitting method into physical factors relative variance and correlation function of the energy density fluctuations of the pulsed optical radiation were analyzed. It has been shown that with increasing optical turbulence the curves of the standard deviation of short pulse beams are reduced compared with the standard deviation of intensity fluctuations of continuous-wave radiation. The spatial structure of fluctuations of the energy density for the high-order modes Laguerre- Gaussian beam with a decrease of the pulse duration becomes more large-scale.
Features of formation of sea surface slicks video images
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The paper deals with surface slicks, their nature and the reasons of formation in the context of remote detection and investigation of dynamic processes in the ocean, as well as at the ocean-atmosphere system. We introduce a simple formalism of formation of contrasts between slick and free sea surface, which takes into account water leaving radiance and qualitatively explains the results of field measurements. The paper gives the results of experimental studies on the registration of slick spots on the surface of coastal waters. Together with the proposed simplified formalism we provide optimal conditions for registration of contrasts between the slick and the free sea surface: the measurement of contrast of P component of the reflected radiation should be taken at angles close to the horizon.
Cloud elements detection on the panoramic images of the sky
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The paper gives a short overview of methods of cloud detection and sky cloud cover level determination based on panoramic sky images obtained with the wide angle lenses of type «Fisheye».
Multiple filamentation Ti:Sapphire-laser pulses in water
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The results of experimental studies of the spatial characteristics of multiple filamentation terawatt femtosecond Ti:Salaser in water are presented. With an increase in initial power laser pulses increases the number of filaments, the length of the field is increased filamentation and reducing the length of the filaments have been shown. The distribution of the filaments in the longitudinal direction of the field of multiple filamentation has a maximum cross-sectional filament is shifted from the center to the periphery of the beam at the end region of filamentation. The minimum diameter of the beam on the track corresponds to the position of the maximum number of filaments. After the point of maximum impulse essentially loses energy in the initial direction of propagation. Upon reaching the pulse power 2 104 Pcr of multiple filamentation area is formed of a hollow cone, the apex directed to the radiation source.
An estimation of the LF-MF high latitude communication radio lines range on surface electromagnetic waves
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The paper is devoted to estimation of the LF-MF high latitude communication radio lines range on surface electromagnetic waves (SEW). A surface impedance of sea areas of water in summer and winter time is considered. An example of calculations of the ground wave field over inhomogeneous impedance paths including stratified inhomogeneous structure “ice-sea” is given. It is shown that due to the emergence of SEW the Arctic radio lines range increases significantly.
Space-time transformation sky brightness at a horizontal position of the sun
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This report discusses some simulation results of the angular distribution of brightness of the sky in the case of molecular scattering in the atmosphere for the benefit of the study of space-time changes of this distribution during the civil twilight.
Coherence of sonic waves at short near-surface paths
V. P. Mamyshev,
S. L. Odintsov
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The coherence of sonic waves at short paths in the atmospheric surface layer is analyzed. The violation of coherence is considered from the viewpoint of variations of phase difference in spatially separated observation sites. The statistics of phase difference at the multichannel reception of signals and its correlation with the statistics of the wind field are studied. Meteorological conditions at the sound propagation path were monitored by ultrasonic anemometersthermometers.
Computer simulation of scalar vortex beams LG0L in time-varying random inhomogeneous media
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Computer modeling of vortex beams LG0L propagation in random inhomogeneous media using the dynamic time varying algorithm of media evolution is presented. The temporal power spectrum of vortex beam LG0L has been investigated by numerical simulation of propagation through atmospheric turbulence. The split-step Fourier method was used for solving scalar wave equation for a randomly inhomogeneous medium with a power-law Kolmogorov spectrum.
Multiple filamentation of laser pulses in the glass
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The results of experiments to study the spatial characteristics of multiple filamentation gigawatt laser pulses in the glass are presented. It is shown that with increasing pulse power multiple filamentation region increases in length and diameter, the distribution of filaments within the region has a maximum value when the power > 105 Pcr area filamentation takes the form of a hollow cone, the apex directed to the source of the laser radiation.
Multiple filamentation of laser beams with different diameters in the air at a 100-meter path
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Results of experiments on controlling the position and length of the filamentation zone of femtosecond laser pulses in atmospheric path length 110 m using different initial spatial focusing and defocusing. The obtained distribution of filaments along the filamentation zone, measured dependence the length of the filamentation zone of the numerical aperture of the beam, its initial radius and pulse power.
Experimental setup for investigation of narrow IR laser beam propagation along horizontal 1300m urban path
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In this paper, we describe an experimental setup for laser beam propagation along a horizontal urban path that can be useful for applications such as wireless power transfer or free-space laser communications. This setup can be used for experiments in different atmosphere conditions. Part of obtained results from experiments for 1064 nm laser beam is presented.
Correction for atmospheric distortion of multichannel laser radiation with the use of phase-conjugation algorithm
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The results of numeric simulation are presented in the paper of multichannel laser radiation propagation under conditions of free diffraction and in a turbulent atmosphere. It was shown that in free space a multichannel system allows one to obtain higher concentration (20-50%) of radiation energy on the object comparing with a Gaussian beam. Intensity of atmospheric distortion decreases with increase of the number of channels. Adaptive correction for turbulent distortions results in two-times increase of energy concentration for systems with 9 and 81 channels. For systems with greater number of channels (201 channels) the results of correction do not depend on turbulence intensity.
Diurnal and annual variation of time delay of pulse signal at long distance
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We propose to determine experimentally the speed of the solar system relative to the selected inertial reference system. On the basis of parallel Lorentz transformation it is shown that for the path length ~ 30 km the diurnal and annual variations of the pulse delay time will have an amplitude ~ 0.24 μs. In accordance with the relativity principle, in any inertial reference frame (IRF) the speed of light is isotropic. We use herein a less stringent assertion: the only inertial system, S0, exists in which the speed of light is independent of direction; both the Earth and the Sun move relative to the system S0.
Modeling of multiple filamentation of terawatt laser pulses on a hundred-meter air path
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The results of numerical simulation of multiple filamentation of terawatt femtosecond pulse Ti:Sapphire laser performed on the experimental data obtained in the airway of a length of 106 m when changing the initial spatial focusing and laser power.
Automatic complex for modeling and forecasting atmospheric processes
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The total zenith tropospheric delay (ZTD) is an important parameter of the atmosphere and directly or indirectly reflects the weather processes and variations. This paper presents a hardware and software complex for continuous measurements and prediction of atmospheric thermodynamics and radio waves refraction index. The main part is a network of ground-based spatially separated GPS/GLONASS receivers, which allows the remote sensing zenith tropospheric delay. GPS-Derived Zenith Tropospheric Delay shows the day to day variation and mesoscale spatial and temporal variability. Comparison with the numerical weather reanalysis fields and solar photometer measurements showed agreement with the relative deviation of less than 10%. Hardware-software complex includes the numerical model of the atmosphere on a computational cluster. A variational assimilation system was used to examine the comparative impact of including satellite derived total zenith tropospheric delay from GPS and GLONASS ground observations. Preliminary results show that the initial field of radio waves refraction index was improved by assimilating the satellite derived ZTD.
Influence of regular refraction on the statistical properties of the fluctuations of the amplitude level of wave in random-inhomogeneous medium
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We consider the statistical properties of the fluctuations of the amplitude level of a wave during propagation in a random-inhomogeneous medium with regular refraction. For two models of the ionospheric layers obtained analytical expressions for the dispersions and correlation functions of the amplitude level in the layers. The results are numerically analyzed for different conditions of radio probing of the ionosphere and presented in graphs.
Urban heat island influence on refraction index fluctuations from the data of spatially separated GPS-GLONASS receivers
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In this paper we show results of troposphere fluctuation analysis and its influence on GPS phase observations. The main object of investigation is a time and spatial correlations between GPS observables induced by the atmospheric mesoscale process in troposphere. We can estimate space structure of atmospheric parameters, using the data from network based on Global Navigation Satellite System receivers. We used mathematical means of turbulence theory and wavelet analysis. The results show a significant effect on GPS signals caused by the mesoscale troposphere process and urban conditions.
Analysis of correlation properties of Shack-Hartmann sensor measurements depending on the characteristics of the intensity distribution in the laser beam
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The evolution of the turbulent distortion is a random process of the wavefront fluctuations, which can only assess the correlation method. The algorithm for computing of the cross wind transport turbulent distortion speed by the sensor measurement for laser beams propagating through the atmosphere is implemented on the basis of correlation analysis of the centroid coordinates. Correlation properties of sensor measurements are dependent on the characteristics of the intensity distribution in the beam. Studies of this dependence are based on numerical experiments.
Coherence of the vortex Bessel beam reflected from the rough surface
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Researches of coherent properties of the vortex Bessel optical beams propagating in a uniform medium after reflection from a rough surface are developed. It is shown, that at low levels of a random roughness of a reflecting surface, the degree of coherence of a vortex Bessel optical beam essentially depends on value of a topological charge of an optical beam. In the central part of a two-dimensional field of degree of coherence the ring dislocation is formed, the number of rings in which is equal to value of a topological charge of a vortex optical beam. At high levels of a random roughness of a reflecting surface, mutual coherence function of a vortex Bessel optical beam coincides with the similar characteristic of an incoherent source.
Parameters of the ring dislocation of a degree of coherence of the vortex Bessel beam in turbulent atmosphere
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In this paper results of theoretical consideration of behavior of degree of coherence of the coherent vortex Bessel optical beam propagating in turbulent atmosphere are presented. It is shown, that at low levels of fluctuations, in the central part of a two-dimensional field of degree of coherence of the vortex Bessel optical beams the ring dislocation is formed, the number of rings in which is equal to value of a topological charge of an optical beam. The structure of a ring dislocation of degree of coherence of the vortex Bessel optical beams in turbulent atmosphere is studied in detail. For this purpose two characteristics of a ring dislocation are entered: its spatial coordinates and width of a ring. Influence of parameters of an optical beam (a cross-section wave number and a topological charge) and atmospheric turbulence on these characteristics of a ring dislocation of degree of coherence of the vortex Bessel optical beam is considered.
Random displacement of the fundamental Bessel beam in turbulent atmosphere
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In the given work the integrated moments of random intensity of the coherent fundamental Bessel–Gaussian optical beams propagating in turbulent atmosphere are theoretically investigated. It was shown, that on short path in the region of weak optical wave fluctuations a variance of the displacements of the center of gravity of a coherent fundamental Bessel–Gaussian optical beam always more than the similar characteristic of a coherent fundamental Gaussian optical beam. Influence of the size of the radiating aperture on value of a variance of the random displacements of the center of gravity of a coherent fundamental Bessel–Gaussian optical beam is analyzed during propagation in turbulent atmosphere with a spectrum of fluctuations of dielectric permittivity of air of Kolmogorov type with finite value of the outer scale of atmospheric turbulence.
Photon mean free path in the metal nanoparticle system
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In the paper comparative evaluation of the photon mean free path in the system of metal nanoparticles and dielectric matrix is performed by means of numerical simulations. As a material of nanoparticles both metals (Ag, Cu) in which the frequency of plasmon resonance falls in the range under study and metals (Al, Ni) in which the plasmon resonance frequency is far from the investigated range have been used. The research has shown that for the studied metals the media based on Al nanoparticles satisfy best the Ioffe-Regel criterion for photons of visible wavelength range.
Investigations of parameters of image quality for adaptive optical systems of BSVT
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The criteria image qualities based on wave front aberration caused by atmospheric turbulence using in adaptive optics are summarized. Atmospheric turbulence profile for Big Solar Vacuum Telescope (BSVT) observatory is obtained based on satellite date. On this based the development of adaptive optics systems of BSVT are discussed.
On the efficiency of algorithms of Monte Carlo methods
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A numerical comparison of algorithms for solving the radiative transfer equation by the Monte-Carlo method is performed for the direct simulation and local estimations. The problems of radiative transfer through a turbid medium slab in the scalar and vector case is considered. The case of reflections from the boundaries of the medium is analyzed. The calculations are performed in a wide variation of parameters of the medium. It is shown that the calculation time with the same accuracy for the local estimation method is less than one - two orders of magnitude.
Estimation of the error of the algorithm for reconstructing the reflection coefficient of the Earth surface on the example of images with the low atmospheric turbidity
Show abstract
An algorithm for atmospheric correction of satellite images combining the consideration of the main factors influencing imaging and a number of techniques allowing the computational time to be decreased considerably is analyzed. On the example of a series of images of the South of the Tomsk Region recorded from 7/13/2013 to 7/17/2013 with the low atmospheric turbidity, a comparison of the results of atmospheric correction using the suggested algorithm with the results obtained using the NASA MOD09 algorithm is performed. The correction error is estimated under assumption of a linear change of the reflection coefficient from image to image. Our comparison demonstrates that the results of correction differ within the correction error.
The modeling of frequency Doppler shift in multibeam weakly non-stationary radio channels
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Under measurement of Doppler shift for signal frequency one define the characteristic average on time or Doppler spectrum. The use of impulses coherent sequence allows to measure Doppler shift of frequency taking into account its small variations caused by non-stationarity of the ionospheric radio channel. In the report we consider the changes of frequency Doppler shift for each beam depending on time under modeling the propagation of impulses coherent sequence through weakly non-stationary ionospheric radio channel.
Influence of vortex phase on random wandering of the modified Bessel-Gaussian laser beam propagating in the atmosphere with weak turbulence
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In this paper, the role of the vortex phase in the initial structure of wave field of the modified Bessel-Gaussian laser beam propagating in the atmosphere with weak turbulence, as well as in statistical regularities of beam wandering is studied by the semi-analytical method. The variance of the beam wandering depending on the diffraction conditions and the degree of turbulent distortions is determined. It is shown that the higher is the topological charge of the beam and its radial frequency, the smaller is the random wandering of the beam.
Estimation of the path-averaged wind velocity by cross-correlation of the received power and the shift of laser beam centroid
Show abstract
We consider the problem of estimation of the average wind speed on atmospheric path from measurements of time series of average power of the laser radiation detected through the receiving aperture and the position of the centroid of the image of the laser beam. It is shown that the mutual correlation function of these series has a maximum, whose position characterizes the average speed of the cross wind on the path. The dependence of the coordinates and magnitude of the maximum of the correlation function from the size of the receiving aperture and the distribution of turbulence along the atmospheric path.
The correlation of the displacements of the images of point sources in the turbulent atmosphere
Show abstract
We consider the problem of determining of the transverse wind speed on atmospheric path from the temporal correlation of the displacements of the centroids of the images of point sources shifted in the transverse. In the framework of the first approximation of the method of small perturbations expressions for correlation functions are outlined. The possibility of estimation of the wind velocity averaged over the optical path is shown.
Estimation of the influence of cloudiness on the Earth observation from space through a gap in a cloudy field
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For atmospheric correction of satellite images, the problem is formulated to estimate the distance from a cloud at which its influence on the satellite image of the Earth surface can be neglected. The Monte Carlo method of conjugate trajectories is used. The gap radius in the field of continuous cloudiness at which the influence of the cloudy medium on the received signal intensity does not exceed 10 % is obtained. It is revealed that for the Lambert law of radiation reflection from the Earth surface, the curve of the dependence of the received signal intensity on the gap radius has a maximum caused by the opposite influence of light scattering by the cloudy medium and radiation reflection by the surface (adjacency effect). To further generalize the examined problem to a stochastic cloud field, the method of direct simulation of photon trajectories in a stochastic medium is compared with G. A. Titov’s method of closed equations in the gap vicinity. A comparison is carried out with the model of the stochastic medium in the form of a cloud field of constant geometric thickness consisting of rectangular clouds whose boundaries are determined by the stationary Poisson flow of points. It is demonstrated that results of calculations can differ at most by 20‒30 %; however, in some cases (for some sets of initial data), the difference for the entire region of cloud cover indices is within 7 %.
Adaptive correction of turbulent distortions by MEMS flexible mirror
Show abstract
In astronomy, there is a very important task - distortion correction. The problem is solved by an adaptive mirror with a variable geometry which can be created based on MEMS. The annex to the adaptive optics, MEMS is membrane mirror of small dimensions, but with a large number of controls. The action of external forces on the controls adjusts the mirror surface shape correction for distortion compensation. Force directed at one control element slightly affects the shape of the mirror surface in the areas where the remaining elements. It is shown that for each control of the mirror can be affected, which is proportional to the calculated value of the sensor by measuring the wavefront coming to the input aperture of the system.
Filamentation of focused and collimated laser beams in liquids
Show abstract
Experimental results of investigations into the transformation of the spectral and spatial characteristics of femtosecond collimated and focused Ti:Sapphire-laser beams with wavelengths of 800 and 400 nm upon filamentation in continuous liquid media are presented. It is shown that broadening of the laser pulse spectrum due to phase self-modulation in the medium with a cubic nonlinearity depends on the pulse power and beam diameter. Dependences of the number of filaments, width of laser radiation spectrum, nonlinear focusing distance, and diameter of the filamentation region on the laser pulse power are measured. The existence of a relative power interval in which the explosive growth of the number of filaments occurs, is established.
Absorption of laser radiation by femtosecond laser-induced plasma of air and its emission characteristics
Show abstract
The energy absorbed by femtosecond laser plasma has nonlinear dependence on incident laser energy. The threshold power for plasma formation is 5.2 GW. Emission of nitrogen molecule, nitrogen molecule ion, atomic oxygen (unresolved triplet O I 777 nm) and nitrogen (triplet N I 742.4, 744.3 and 746.8 nm) lines is detected. Molecular emission consists of second positive and firs negative systems of nitrogen. Time-resolved spectroscopy of plasmas shows short molecular line emission (up to 1 ns) and long atomic line emission (up to 150 ns).
Dynamical anisotropy of the optical propagation paths
Show abstract
Dynamics of laser beam intensity profile spatial modulations over a model tropospheric path with the controlled meteorological parameters was studied. Influence of the underlying surface temperature as well as the side wind load were considered. The increase of dynamic anisotropic disturbances saturation with the path length was observed. Spatio-temporal correlation characteristics of the directivity pattern in the signal beam registration plane were obtained. Proposed method of the experimental samples analysis on the base of chronogram with the following definition of the dynamic structure tensors array allows to estimate local and averaged projections of the flow velocities over the chosen spatio-temporal region and to restore their geometry in the zone of intersection with the signal beam. Additional characteristics suggested for the diagonalized local structure tensors such as local energy capacity and local structuredness are informative for the estimation of the inhomogeneities spatial dimensions, time of access through the section considered, the dynamics of energetic jets. The concepts of rotational and translational dynamic anisotropy are introduced to discriminate the types of the changes of the local ellipsoids axes orientation as well as their values. Rotational anisotropy shows itself in the changes of the local ellipsoids orientation, thus characterizing the illumination variation over the beam cross-section. Translational anisotropy describes the difference between the axes values for local ellipsoids.
Influence of the outer scales of temperature and dynamic turbulence on the characteristics of transmitted acoustic radiation
Show abstract
In the present work, the problem of propagation of monochromatic acoustic radiation in the lower 500-meter layer of the plain stratified moving turbulent atmosphere is solved by the Monte Carlo method. The influence of the parameters of models of the outer scales of temperature and dynamic turbulence on the intensity of transmitted acoustic radiation intensity is investigated.
The dispersion of surface plasmon-polaritons in the metal-nanocomposite system
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The article presents the results of computing simulation of surface plasmon-polaritons’ dispersive properties at the interface between «a composite medium based on Al, Ag, Ni, Cu nanoparticles and a substrate made of the same metals» in the visible wavelength band. It is shown that the surface plasmon-polaritons’ dispersive properties in these structures can be changed in a wide range by altering the nanoparticles concentration.
Testing forward model against OCO-2 and TANSO-FTS/GOSAT observed spectra in near infrared range
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An existing software package FIRE-ARMS (Fine InfraRed Explorer for Atmospheric Remote MeasurementS) was modified by embedding vector radiative transfer model VLIDORT. Thus the program tool includes both thermal (TIR) and near infrared (NIR) regions. We performed forward simulation of near infrared spectra on the top of the atmosphere for outgoing radiation accounting multiple scattering in cloudless atmosphere. Simulated spectra are compared with spectra measured by TANSO-FTS/GOSAT and OCO-2 in the condition of cloudless atmosphere over Western Siberia. NCEP/NCAR reanalysis data were used to complete model atmosphere.
Neural network technologies for image classification
Show abstract
We analyze the classes of problems with an objective necessity to use neural network technologies, i.e. representation and resolution problems in the neural network logical basis. Among these problems, image recognition takes an important place, in particular the classification of multi-dimensional data based on information about textural characteristics. These problems occur in aerospace and seismic monitoring, materials science, medicine and other. We reviewed different approaches for the texture description: statistical, structural, and spectral. We developed a neural network technology for resolving a practical problem of cloud image classification for satellite snapshots from the spectroradiometer MODIS. The cloud texture is described by the statistical characteristics of the GLCM (Gray Level Co- Occurrence Matrix) method. From the range of neural network models that might be applied for image classification, we chose the probabilistic neural network model (PNN) and developed an implementation which performs the classification of the main types and subtypes of clouds. Also, we chose experimentally the optimal architecture and parameters for the PNN model which is used for image classification.
On atmospheric turbulence structure constant measurement by a passive optical method
Show abstract
Development of a passive optical method for measuring the strength of atmospheric turbulence (atmospheric air refractive index structure constant Cn2) from image jitter is discussed. A high-rate digital camera and computer processing, including fast parallel 2D image correlation tracking algorithms, are shown to allow for real-time Cn2 measurements. The results obtained by passive and active optical methods together with meteorological station support of the experiment are compared.
A computer-based simulator of the atmospheric turbulence
Show abstract
Computer software for modeling the atmospheric turbulence is developed on the basis of a time-varying random medium simulation algorithm and a split-step Fourier transform method for solving a wave propagation equation. A judicious choice of the simulator parameters, like the velocity of the evolution and motion of the medium, turbulence spectrum and scales, enables different effects of a random medium on the optical wavefront to be simulated. The implementation of the simulation software is shown to be simple and efficient due to parallel programming functions from the MKL Intel ® Parallel Studio libraries.
Phase functions, glories, fogbows and coronas for clouds with mirror-transformed gamma- and bimodal-distributions
Show abstract
In this paper we study the phase functions for water-droplet clouds and fogs computed by the Mie theory for specific bimodal and “mirror”- transformed droplet size gamma-distributions. In addition, we construct images of coronas, fogbows and glory that can occur for such cloud and fog models.
Threshold characteristics cavityless lasing in composites with agglomerated metal and dielectric nanoparticles
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The paper presents results of experimental studies of the threshold characteristics of lasing in thin layers (20 microns) of a solution of rhodamine 6G with agglomerates of metal and dielectric nanoparticles. The maximum decrease in the lasing threshold was more than two orders for a wide range of changes in the concentration of metal agglomerates. For dielectric nanoparticle agglomerates range of maximum lowering of the threshold is 5 times lower. This is due to different mechanisms of formation of lasing in these environments.Comparing the efficiency of lasing in layers with metal agglomerates proves on expediency using them to create a low threshold microlasers.
Atmospheric channel for bistatic optical communication: simulation algorithms
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Three algorithms of statistical simulation of the impulse response (IR) for the atmospheric optical communication channel are considered, including algorithms of local estimate and double local estimate and the algorithm suggested by us. On the example of a homogeneous molecular atmosphere it is demonstrated that algorithms of double local estimate and the suggested algorithm are more efficient than the algorithm of local estimate. For small optical path length, the proposed algorithm is more efficient, and for large optical path length, the algorithm of double local estimate is more efficient. Using the proposed algorithm, the communication quality is estimated for a particular case of the atmospheric channel under conditions of intermediate turbidity. The communication quality is characterized by the maximum IR, time of maximum IR, integral IR, and bandwidth of the communication channel. Calculations of these criteria demonstrated that communication is most efficient when the point of intersection of the directions toward the source and the receiver is most close to the source point.
Spectral shaping of lasing active medium with agglomerated nanoparticles of metals and dielectrics
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In this paper presented a series of experiments determine the spectral characteristics of random lasing in lasers with agglomerated nanoparticles metals and dielectrics. The data allowed us to establish that, in the active heterogeneous environment, there are various gain effects of lasing the impact of which is determined nanoparticles concentration.
Clustering of filament in air
Show abstract
Approach to the description of effect of a clustering in air is offered. This effect can be described as an impurity clustering in the squeezed streams. On the basis of the diffusive equations for density of number of filament estimates of the sizes cluster from the size of average intensity are carried out. The equations for density of number of filament were formulated by authors for the description of a multiple filamentation in air earlier.
Spectral image fusion based on multi-scale wavelet analysis
Alexander S. Machikhin
Show abstract
The problem of spectral image fusion in order to combine the most informative areas into one image is considered. Algorithm based on joint multi-scale image analysis is discussed. Processing of the images at each pyramid level allows to extract and to combine image features of the same scale. This approach provides a high speed of processing and high quality of the resulting image and may be applicable for real-time applications.
Statistical numerical simulation of polarized terahertz radiation propagation in a cloud layer
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The results of numerical simulation of polarization characteristics of terahertz signals from a ground-based remote sensing system in stratus clouds for various models of liquid-droplet clouds are compared. Models of the scattering medium take into account the vertical stratification of the water vapor concentration in the atmosphere. The model of droplet size distribution includes droplets larger than 20 μm in radius. They are referred to as large droplets, while droplets with radius 1<r<20 μm are referred to as small ones. The model of a cloud layer was developed with allowance for a difference in the vertical stratification of the mean radii of the small and large droplets.
Characterization of vortex beams synthesized on the basis of a fiber laser array
Show abstract
A technique for generation of optical vortex beams with a variable orbital angular momentum on the basis of a fiber laser array is suggested. The technique is based on controlling the radiation phase of individual subapertures of the array. Requirements for parameters of a device for vortex beam generation are determined (the number and size of subapertures and their arrangement). The propagation dynamics of a vortex beam synthesized is compared with that of a continuous vortex beam in free space and in a turbulent atmosphere. Spectral properties of a beam synthesized, which is represented as a superposition of different azimuth modes, are determined during its free-space propagation. It is shown that energy and statistical parameters coincide for synthesized and continuous vortex beams when propagating through a turbulent medium.
Filtration of optical image distortions for retrieving the drift velocity of atmospheric turbulence inhomogeneities
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Possibilities of retrieval of the drift velocity of atmospheric turbulence inhomogeneities from a video sequence of incoherent images of an object are studied numerically in the work. A method for filtration of turbulent distortions of an image by their characteristic sizes is suggested with the aim to determine the wind speed at different segments of an observation path. The method testing for the cases of two layers of turbulent inhomogeneities that drift in different (mutually normal) directions has shown high accuracy of retrieval of their drift velocities.
Numerical research of measurements of Shack-Hartmann wavefront sensor according to the parameters of its optical parts and the intensity of turbulent distortions
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The wavefront sensor of Hartmann type consists of two parts: the optical and algorithmic. The parameters of the optical part of the sensor may vary. Since the time of “frozen” turbulence due to the Fried’s length and to the cross wind transport turbulent distortion speed, the measurement Shack-Hartmann sensor depend on the intensity of turbulent distortions. In this paper are presented the results of the analysis of the measurements of the sensor according to the size of lens array and to the intensity of turbulent distortions. The analysis is performed on basis of a numerical model of the Shack-Hartmann wavefront sensor and on Kolmogorov’s turbulence model.
Optical Investigation Of Atmosphere And Ocean
To the technique of determination of phase matrices of high-level clouds with a polarization lidar
Show abstract
A comparative analysis of errors of two methods for the determination of phase matrices of high-level clouds with a ground-based lidar is performed.
Retrieval of the aerosol microstructure parameters from sun photometer data measured in a limited spectral range
Show abstract
The influence of the upper limit λmax of the spectral range in which the atmospheric transmission is measured on the results of retrieval of the aerosol microstructure parameters when solving the inverse problem of sun photometry from the data of numerical modeling and field experiments is investigated. In the numerical experiment the aerosol model comprising fine submicron (f) and coarsely dispersed (c) particle fractions is used. Here λmax is chosen from the range 1.052-3.973 μm. The method of integral distributions is used to solve the inverse problem. It is demonstrated that the limited spectral range causes underestimation of the contribution of large particles to aerosol distributions. In particular, at λmax = 1.246 μm, losses of the retrieved concentration of particles of the c fraction against the background of the decreased (to 18 % at λ = 1.246 μm) volume aerosol concentration can reach 42 %.
Algorithm of retrieval of aerosol microstructure from sun photometry data based on a hybrid model
Show abstract
Special features of determining the aerosol microstructure from spectral measurements of the aerosol optical depth (AOD) caused by low information content of the solution for large particles are considered. Such conditions are observed when sizes of aerosol particles are much larger than the maximum measurement wavelength. We propose an AOD inversion algorithm based on a hybrid model of aerosol microstructure. The model includes a description of the disperse aerosol composition in the informative range of particle sizes based on the integral distribution function supplemented with a parametric representation of the microstructure of large particles. Results of approbation of the algorithm for inversion of the data of field experiments are presented that demonstrate the feasibility of retrieving the microstructural parameters of coarsely dispersed aerosol fraction when the upper limit of the spectral range decreases from 4 to 1.56 μm.
Application of thermography in experimental studies of plasma jets
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The paper presents the experimental studies of the optical properties for the plasma jet in the mid-IR range.
Еstimation of the turbulence scale in flame using the method of IR diagnostics
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The paper presents the experimental measurements of temperature fields in a narrow mid-infrared spectral range during combustion of different fuels (plant fuels, alcohol, petroleum, kerosene, and diesel fuel). The spectra of temperature changes are obtained in flame. The scale of turbulence in flame is estimated on the basis of temperature nonuniformity measurements and the analysis of temperature spectra in flame.
Measuring the characteristics of stratospheric aerosol layer and total ozone concentration at Siberian Lidar Station in Tomsk
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We consider the results of long-term remote optical monitoring, obtained at the Siberian Lidar Station of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences in Tomsk (56.5 °N, 85.0 °E). The scattering characteristics of stratospheric aerosol layer, obtained according to data of lidar measurements since 1986, are presented. We analyze the trends of changes in the total ozone (TO) content over Tomsk for the period 1996-2013 according to data of spectrophotometric measurements with employment of TOMS satellite data for the period 1979- 1994. We determined the periods of elevated content of stratospheric aerosol over Tomsk after a series of explosive eruptions of volcanoes of Pacific Ring of Fire and Iceland in 2006-2011. Since the second half of 1990s, researchers record an increasing TO trend, equaling 0.65 DU/yr for the period 1996-2013.
Comparison of the physical optics code with the GOIE method and the direct solution of Maxwell equations obtained by FDTD
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A comparison of the physical optics code and GOIE method to solve the problem of light scattering by hexagonal ice crystals has been presented. It was found that in the case of diffraction on a hole in the perpendicular screen, both methods give the same diffraction scattering cross section for the diffraction angles up to 60 degrees. The polarization elements of the Mueller matrix in this case differ significantly even for the angles of 15-30 degrees. It is also shown that in the case of diffraction on the tilted screen, the difference between these methods may be significant. The comparison of the results with the exact solution obtained by FDTD has confirmed that the difference between these methods is not significant for the case of diffraction on the perpendicular screen, but it is slightly preferable to use the GOIE for the calculations. The good agreement with the exact solution confirms the possibility of using the method of physical optics to solve the problem of light scattering by particles with characteristic size greater than 10 microns.
Granulometry of atmospheric suspension of Norsk State Reserve (Amur Region, Russian Federation)
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The paper presents the results of studying of atmospheric suspensions contained in snow samples of Norsk state reserve (seasons 2013/2014 years). The snow samples gathered at 5 areas were revealed to contain particles size of less than 10 μm in ecologically low concentrations (up to 13 %). Generally the particles of 3rd (10-50 μm), 5th(100-400 μm) and 7th( more700 μm) size classes prevail at all areas. The particles at all screening areas have relatively small area of a specific surface - from 552,95 to 3272,12 cm2/cm3. It may be deducted that from the point of view of microsize atmospheric pollution Norsk State Reserve belongs to territories with favourable conditions.
Granulometry of atmospheric suspension of Zeysky State Reserve (Amur region, Russian Federation)
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The paper presents the results of granulometry studying of particles of atmospheric suspension contained in snow samples collected in Zeya state reserve (seasons winter 2013/2014 years). Snow samples collected at 5 stations were revealed to contain the particles the size of less than 10 μm in ecologically insignificant concentrations (up to 4%). Generally, the particles of 3rd (10-50 μm) and 6th (400-700 μm) size classes prevail at all sampling stations. The particles at all sampling stations have relatively small specific surface area - from 401, 87 to 4720, 22 сm2/сm3. It is possible to draw an inference that from the point of view of micro size pollution of atmosphere Zeya state reserve is considered to be a territory with farourable conditions.
Temporal dynamics of optical-microphysical characteristics of atmospheric aerosol at the Spitsbergen Archipelago in 2011-2014
D. G. Chernov,
V. S. Kozlov,
M. V. Panchenko,
et al.
Show abstract
In 2011–2014, the Institute of Atmospheric Optics (IAO SB RAS, Tomsk) and the Arctic and Antarctic Research Institute (AARI, St. Petersburg) conducted field investigations of the near-ground aerosol characteristics near Barentsburg (Spitsbergen Archipelago) in the spring and summer seasons. The particle number density in the size range 0.3-20 μm, size distribution of particles, and mass concentrations of aerosol and black carbon were measured round-the-clock every hour with Grimm 1.108 and 1.109; and AZ-10 optical counters. The mass concentration of black carbon was measured by the MDA-02 aethalometer developed by the IAO SB RAS. Series of observations are obtained, annual and seasonal average values and their standard deviations are estimated, and seasonal and annual dynamics of the studied parameters is analyzed. Peculiarities of the temporal dynamics of average values of the aerosol characteristics are revealed and compared with the data of observations at other stations of the Spitsbergen Archipelago and in different regions of the Russian Arctic and Subarctic.
Development of photodetectors for recording lidar signals in the photon counting and analog modes
A. S. Slesar,
A. P. Chaikovskii,
S. V. Denisov,
et al.
Show abstract
A number of unified photodetector modules providing for recording lidar signals in the wavelength range from 0.26 to 1.6 μm in the modes of analog signals and photon counting are developed on the basis of photomultiplier tubes and avalanche photodiodes. The software is created for control of the photodetector modules, as well as the test bench for measuring their characteristics is designed.
Testing the algorithms for taking into account relative humidity of air in the model of optical characteristics of absorbing aerosol
Show abstract
The paper presents the results of modeling of the aerosol optical characteristics taking into account the effect of relative humidity of air. Two algorithms were applied: humidification by the Hanel formula with the same parameter of condensation activity for all particles and introducing the dependence of aerosol hygroscopic properties on the particle size. The results of calculations are compared with the data of field measurements.
Summary of long-term data on latitudinal dependence of the near-water aerosol microphysical characteristics in eastern Atlantic
Show abstract
Latitudinal dependences of aerosol microphysical characteristics are analyzed. The data were obtained in the Russian Antarctic Expedition (RAE) onboard the expedition vessels "Akademik Fedorov" and "Akademik Treshnikov" in 2006- 2014, as well as the research vessel "Akademik Sergey Vavilov" in 2004.
Spatial variability of aerosol and black carbon concentrations in the troposphere of the Russian Arctic
Valerii S. Kozlov,
Mikhail V. Panchenko,
Jean D. Paris,
et al.
Show abstract
A cycle of flights of the Optik TU-134 Flying Laboratory of IAO SB RAS over regions of Western Siberia and the Russian Arctic (55.0–74.8°N, 61.3–82.9°Е) was carried out on October 15-17 of 2014 within the framework of the YAK-AEROSIB Russian—French Project. The mass concentrations of submicron aerosol and Black Carbon (BC) in the troposphere up to a height of 8.5 km were measured in the flights. The ranges of variability were 0.3-20 μg/m3 for the aerosol concentration and 0.02-1 μg/m3 for the BC concentration. In the subpolar latitudes of 71-74.8°N, the lower levels of aerosol (0.8-6 μg/m3) and BC (0.02-0.3 μg/m3) were observed. The comparison of the results of airborne sensing in 2008 and 2014 has shown that in the Western Subartic the aerosol and BC concentrations in the vertical profiles up to six times exceeded those observed in the Eastern Subarctic (0.3-1 μg/m3 and 10-50 ng/m3). The excess of the mean integral BC concentrations and the aerosol optical depth was, on average, 2-2.5 times (0.16 mg/m2; 0.02). In the region of the Kara Sea at heights of 0.5-2 and 4-6 km, the excess of the aerosol content in the western sector in comparison with the eastern one was, on average, 2 times, while for the black carbon the excess achieved 7 times at heights of 1-2 km (0.25- 0.035 μg/m3). The mean integral concentrations of aerosol and black carbon ∼ 1.3 times exceeded those in the clearer eastern region of the sea (0.31 mg/m2; 0.049). The obtained estimates indicate the decrease of the aerosol and BC concentrations in the subpolar latitudes of the Russian Federation from the west to the east.
Polarization lidars with conical scanning for retrieving the microphysical characteristics of cirrus clouds
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The paper presents the first results of observations of cirrus clouds by polarization lidars with conical scanning, which were developed in Hefei (China) and in Tomsk (Russia). The light scattering matrix of ice crystal particles of cirrus clouds has been calculated for the first by the authors within the framework of the physical optics approximations in the case of conical scanning lidar. It is found that in this case the Mueller matrix consists of ten non-zero elements, four of which are small and can’t be applied to interpret the azimuthal distribution of particle orientation. All the diagonal elements have a strong azimuthal dependence. Among the off-diagonal elements only one element M34 carries additional information for interpreting the azimuthal distribution.
Interference phenomena at backscattering by ice crystals of irregular shape
Show abstract
It is shown that light backscattering by hexagonal ice crystals of cirrus clouds is formed by both diffraction and interference phenomena. Diffraction determines the angular width of the backscattering peak and interference produces the interference rings inside the peak. By use of a simplest model for distortion of the pristine hexagonal shape, we show that the shape distortion leads to both oscillations of the scattering (Mueller) matrix within the backscattering peak and to a strong increase of the depolarization, color, and lidar ratios needed for interpretation of lidar signals.
Spatial distribution of atmospheric aerosol optical depth over Atlantic Ocean along the route of Russian Antarctic expeditions
Show abstract
During recent decade, Microtops and SPM portable sun photometers are used to perform annual measurements of aerosol optical depth (AOD) and water vapor content of the atmosphere over Atlantic Ocean along the route of the Russian Antarctic expeditions (RAE). The data accumulation has made it possible to analyze the specific features of the spatial distribution of spectral AOD of the atmosphere along eastern RAE route and identify six basic regions (latitudinal zones). The statistical characteristics of AOD in the identified oceanic regions in winter and spring periods are discussed. The estimates of finely and coarsely dispersed AOD components in different regions, as well as the interannual atmospheric AOD variations, are presented.
Coherent and incoherent additions of light beams at solutions of the light scattering problem by use the beam tracing method within the framework of physical optics
Show abstract
Interference effects between the scattered beams in the problem of light scattering by atmospheric ice crystals have been studied. Since the crystals are much larger than the wavelength, it is shown that the interference effects can be neglected if the crystal sizes are statistically varied more than 5% of the mean size. As a result, any calculations of the optical properties of the crystals performing an averaging over crystal sizes can be effectively replaced by the procedure of the incoherent addition of the scattered beams. This procedure allows us decrease the execution time up to 100 times.
Assessment of changes in the qualitative composition and properties of dissolved organic matter on hydro-optical characteristics when fractional filtration of natural water
Show abstract
The paper discusses the changes hydro-optical parameters that characterize the qualitative composition of dissolved organic matter (DOM), during fractional filtering though large (4.5 μm and 1.76 μm) and small (0.9 μm) filters. A loess reservoir lake Khanka containing great amount of suspended inorganic matter were selected as the research object. In order to assess changes in the composition of the DOM the following parameters were selected: index of the degree exponent of absorption spectrum, the specific absorption coefficient, relative specific fluorescence yield and relative specific fluorescence,. The research has shown that not only the content of organic matter during adsorption on the surface of the suspension is changing during filtration, but also the composition.
Determination of concentration and size distribution of black carbon in submicron aerosol from data of nephelometric measurements of angular scattering coefficients
Valerii S. Kozlov,
Rustam F. Rakhimov,
Vladimir P. Shmargunov
Show abstract
The possibility of determining the Black Carbon (BC) concentration and its size distribution in submicron aerosol from data of polarization spectronephelometric measurements of angular aerosol scattering is demonstrated for the first time. The data of simultaneous nephelometric and aethalometric measurements of BC concentration in wood smoke are compared. The inverse problem is solved from measurements of 40 polarization components of spectral coefficients of angular scattering, and aerosol filling factors and the imaginary part of the complex refractive indexes are determined for subfractions of ultrafine- (radii of 30-100 nm), fine- (100-430 nm), and coarse-disperse (430-770 nm) particles. Then the total BC concentration, its size distribution, and BC fraction are estimated in the approximation of homogeneous volume internal mixture of BC and nonabsorbing matter. The analysis shows that at the long evolution of smoke aerosol, nephelometric and aethalometric estimates of the BC concentrations are in a good agreement. The discrepancy averages about 16% for concentrations varying in a range 30-1000 μg/m3.
Variabilitiy of condensation properties of mixed smoke at different stages of its long evolution
Valerii S. Kozlov,
Rustam F. Rakhimov,
Vladimir P. Shmargunov
Show abstract
The experiment on the study of dynamics of optical-microphysical properties of aerosol for 6 days with periodic moistening of particles in the range of the relative air humidity 45-95% was carried out for the mixed wood smoke in the Large Aerosol Chamber (volume of 1800 m3) of the Institute of Atmospheric Optics SB RAS. The dynamics of the disperse composition and complex refractive indices of fractions, extinction and scattering coefficients, lidar scattering and single scattering albedo is analyzed based on the data of spectral nephelometric measurements of the angular scattering coefficients, solution of the inverse problem for subfractions of ultrafine-, fine-, and coarse-disperse particles, as well as calculations by the Mie theory. It is shown that, in the course of smoke ageing, peculiarities of variations of aerosol characteristics in the field of the variable air humidity change significantly. An important factor in variations of optical-microphysical properties of the mixed “dry” and moistened smoke is the processes of migration of the ultrafine black carbon over the size spectrum present at all temporal stages.
DYNAMICS of optical-microphysical properties of atmospheric haze at stepwise change of air humidity
Rustam F. Rakhimov,
Valerii S. Kozlov,
Vladimir P. Shmargunov
Show abstract
The three-day cycle of spectronephelometric measurements of the angular aerosol scattering coefficients of the near-ground aerosol at the stepwise increase/decrease of the relative air humidity of 50, 65, 75, 85, and 90% has been conducted in the Large Aerosol Chamber of IAO SB RAS filled with the atmospheric air. The results of solution of the inverse problem have shown that the condensation coarsening of particles at the simultaneous decrease of their refractive index and the imaginary part of the complex refraction index (absorption index) is stably observed with an increase of the relative air humidity for ultrafine (with radii of 30-100 nm) and fine (100-370 nm) particles. However, for the coarse particles (370-600 nm), the increase of humidity leads to the effect of increase of the refractive index from 1.60 to 1.66, while the values of the absorption index are low (∼10-5) and vary only slightly at the aerosol humidification. The effective radius of particles (165-195 nm) and the single scattering albedo (0.71-0.83) increase synchronously with an increase of the air humidity. For two days of aerosol evolution in the closed volume of the chamber, the total extinction and absorption coefficients also vary synchronously with the variation of humidity, but at the third day the influence of humidity on the absorption coefficient was not observed. A possible reason for appearance of specific condensation peculiarities is the influence of humidity variations on the inflow/outflow of particles smaller than 30 nm and larger than 600 nm having various physical-chemical composition into the optically active size range.
Results of SPM sun photometer measurements at Mirny Antarctic station (58-60th RAE)
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The SPM portable sun photometer observations in the wavelength range of 0.34-2.14 μm are performed at Mirny Antarctic station since fall 2013. The data obtained are used to calculate the aerosol optical depth (AOD) and water vapor content of the atmosphere. The sun photometer intercalibration results and statistical characteristics of interdiurnal and seasonal variations in spectral AOD of the atmosphere are discussed. Estimates of interannual variations in the atmospheric AOD in the region of Mirny station and in the coastal zone of Antarctica are presented. The global background level of AOD of the Antarctic atmosphere is noted to be still about 0.02 at the wavelength of 0.5 μm.
Finely and coarsely dispersed components of atmospheric aerosol optical depth in the region of Tomsk: interannual and seasonal variations
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Based on multiyear sun photometer measurements in the region of Tomsk, we discuss the specific features of seasonal and interannual variations in the finely and coarsely dispersed components of aerosol optical depth (AOD) of the atmosphere. The average spectral dependences and characteristics of AOD in characteristic (for annual behavior) months of the year, i.e., February, April, July, and October, are presented. The absence of statistically significant trend in multiyear AOD variations is noted. The annually average value is 0.04 for coarsely dispersed AOD component, and 0.12 for finely dispersed component (without accounting for the anomalous value 0.11 in 2012).
Long path DOAS measurements of atmospheric pollutants concentration
Show abstract
A differential optical absorption spectroscopy gas-analyzer consisted of a coaxial telescope, a spectrometer, an analyzer and retroreflector was successfully tested. A high pressure 150-W Xe arc lamp was employed as a light source. In order to record the spectra, a monochrometer with a grating and photodiode array was used. Gas analyzer spectral data bank includes more than 35 moleculas absorbed in UV spectral region. The measured absorption spectra were evaluated by using a least-squares fit to determine the average mixing ratio of each species in the atmosphere. As a result of experiments time series of concentrations of gases polluting the atmosphere were trace measured. Minimally detected concentration on pathlength 480 m is the unit of ppb at the time of accumulation of 2 min. The results of the field test measurements of pollutants in Tomsk city are presented.
Comparison of the effectiveness of optic atmosphere investigation tasks distribution techniques in local network
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The research introduces a comparative review of atmosphere investigation tasks distribution techniques in local network. The article provides information about algorithms, simulation modeling methods and the results of the modeling.
Lidar sensing of clouds from under the water
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The possibility of reconstructing the cloudiness parameters from measurements with a lidar immersed at depths of 10– 25 m is analyzed. Theoretical analysis is performed by the Monte Carlo method for lidars with realistic technical parameters, two optical types of ocean waters, different optical cloud models, and marine atmosphere in the presence of a fog. It is demonstrated that under typical conditions, cloudiness can reliably be detected up to altitudes of several hundred meters above the sea level. A change of the laser divergence angle and receiver field-of-view angle has a stronger effect on the character of lidar signal reflected from sea water than from cloudiness. A large contribution of multiply scattered radiation to lidar return signals calls for the development of mathematical methods that take it into account to increase the measurement accuracy.
Estimation of aircraft wake vortex parameters from data measured by a Stream Line lidar
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A method for estimation of aircraft wake vortex parameters (coordinates of axis and circulation of vortices) from raw data measured by a pulsed coherent Doppler lidar “Stream Line” has been offered. By numerical simulation we found optimal measurement parameters, with which it is possible to obtain information about the wake vortices, despite the low level of echo signal inherent to this lidar. The method was tested in an experiment at the airfield of Tomsk airport. The results of the experimental data processing are consistent with theoretical calculations for the type of aircrafts involved in this experiment.
Specifics of the hail parameter measurements using the optical precipitation gauge
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There are specifics of use of the obtaining and analyzing precipitation particle shadow images method for the hail precipitation investigations. Descriptions of the method and operation of the new optical rain gauge measuring system are presented. There are estimations of the device capabilities and prospects of its use for measurement of hail characteristics.
Lidar investigation of the atmospheric boundary layer dynamics in the coastal zone of Lake Baikal
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Strategy of measurements by a coherent Doppler lidar “Stream Line” and procedure of the measured data processing for the visualization of spatial-temporal structure of the wind field in the atmospheric boundary layer have been developed. Lidar investigation of the boundary layer dynamics in the coastal zone of Lake Baikal has been conducted. As a result, in particular, we found out that in this region at a height of around 200 m above the earth surface a narrow jet flow took place during most of the time of our ten-day experiment.
Optical characteristics of aerosol trioxide dialuminum at the IR wavelength range
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In this work, a numerical study of the transmission function, extinction coefficient, scattering coefficient, and absorption coefficient of the aerosol generated by the jet engine emissions was performed. Analyzing the calculation results of the IR optical characteristics of anthropogenic emissions containing the dialuminum trioxide was carried out. The spectral features of the optical characteristics of the medium caused by the average size, concentration and complex refractive index of the particles were illustrated.
Atmospheric correction of satellite data
Show abstract
Atmosphere responses for more than 90% of all radiation measured by satellite. Due to this, atmospheric correction plays an important role in separating water leaving radiance from the signal, evaluating concentration of various water pigments (chlorophyll-A, DOM, CDOM, etc). The elimination of atmospheric intrinsic radiance from remote sensing signal referred to as atmospheric correction.
Raman gas analyzer applicability to monitoring of gaseous air pollution
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It is shown that the main problem, arising when designing a stationary Raman gas analyzer intended to monitor gaseous air pollutions, is to get SRS signals of sufficient intensity. The engineering solutions are presented that provide the required sensitivity (~ 50–100 ppb). It is achieved by compressing a gas medium under analysis and gaining intensity of the exciting laser radiation.
Portable mercury gas analyzer with a lamp filled with natural mercury isotope mixture
A. I. Abramochkin,
V. A. Korolkov,
N. G. Mutnitsky,
et al.
Show abstract
Description is presented of a portable mercury gas analyzer operating on the differential absorption method. A gas discharge capillary lamp filled with natural mercury is used as a radiation source. Transverse Zeeman effect is used to get two wavelengths.
Remote detection of gas markers of artificial explosives
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At the recent years, the increasing interest to laser methods of detection of harmful and dangerous admixtures in the open atmosphere is observed. In this work, experimental results are given of remote detection of acetone vapors, which is the marker of triacetone triperoxide (TATP), with the use of the frequency-pulse 13С16О2 laser with generation line at 11.2 μm.
Cr2+:ZnSe laser for mid-IR remote sensing of atmospheric gases
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This paper presents study results of the technical features of Cr2+:ZnSe laser, which performs differential absorption LIDAR measurements for atmospheric constituents and pollutants. Simulation of atmospheric optical depth was carried out using HITRAN2012 for a Cr2+:ZnSe laser spectral wavelength tunability range on the line-by-line basis. The best wavelengths pairs of λON and λOFF and suitable gases to be detected in DIAL measurements of several molecular species were chosen.
Measurement of ozone concentration in the lower stratosphere and upper troposhere
Show abstract
We describe an ozone lidar and consider an algorithm for retrieving the ozone concentration, taking into consideration the aerosol correction. Results of lidar measurements at wavelengths 299 and 341 nm well agree with model estimates, indicating that ozone is sensed with acceptable accuracies in the altitude range of about 6-18 km. It should be noted that the retrieved profiles of altitude distribution of ozone concentration more closely resemble those from satellite data than according to Krueger model. A lidar is developed and put into operation at Siberian Lidar Station (SLS) to measure the vertical ozone distribution (VOD) in the upper troposphere-lower stratosphere. Sensing is performed according to the method of differential absorption and scattering at wavelength pair 299/341 nm, which are respectively the first and second Stokes components of stimulated Raman scattering (SRS) conversion of the fourth harmonic of Nd:YAG laser (266 nm) in hydrogen.
Justification of choice of the spectral range for the study of combustion processes with the use of thermography in the middle IR range
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The paper presents the emission spectra of flame formed during combustion of different fuels and gives the grounds for application of various narrow spectral ranges in the mid-infrared region to record the temperature fields in flame and flame screened objects.
Laboratory investigation of fire exposure on wood by thermal imagery and thermocouple approach
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The impact of spot fire on wood different-shaped samples (flat and cylindered sample) is studied under laboratory conditions. Using thermal imagery and a thermocouple method, the temperature is determined on the surface of the test samples after the impact of the fire front; the possibility of wood ignition is analyzed for the chosen parameters of the experiment.
Remote detection of traces of high energetic materials
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The possibility of remote detection of traces of high energetic materials using laser fragmentation/laser-induced fluorescence (LF/LIF) method is studied. Experimental data on the remote visualization of traces of trinitrotoluene, hexogen, composition B, octogen, and tetryl obtained at a distance of 5 m with a scanning lidar detector of traces of high energetic materials are presented.
Mathematical model of a two-stage process of laser fragmentation of nitrocompound molecules and subsequent laser-induced fluorescence of characteristic fragments
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The paper presents a mathematical model describing the kinetics of the two-stage process of laser fragmentation of vapors of nitrocompounds and subsequent nitric oxide (NO-fragments) laser-induced fluorescence. The use of the developed model in the lidar equation for the case of fluorescent objects allows to calculate the expected value of the lidar signal for a particular nitrocompound on the basis of spectroscopic information about the object of detection, parameters of the radiation propagation medium, and transceiver equipment parameters.
The formation of the sky brightness with horizon position of the sun
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This report discusses some simulation results of the angular distribution of brightness of the sky in the case of molecular scattering in the atmosphere during the civil twilight with solar zenith angles 90 ° - 94 °.
Comparison of one-parameter and two-parameter models of aerosol extinction for experimental data of the arid zone of Kazakhstan
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Comparison of four aerosol models is carried out: two one-parameter models for a ground layer of the arid zone of Kazakhstan, two-parameter model for horizontal paths and two-parameter model for horizontal and slant paths. It is shown that the models obtained using the new methods for construction of linear regression and separation of the components allow physically correct retrieval of not only the values of the aerosol extinction coefficients, but also their root mean square deviations.
Generation and parametric amplification of femtosecond radiation up to terawatt power in the mid-infrared
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Nonlinear optical schemes for generation of terawatt femtosecond pulses in the range of 2-10 μm using multiterawatt laser radiation of the two-channel system created in the ILP SB RAS are presented and discussed. It is shown that the use of large aperture LBO crystals and AgGaGeS4 for difference frequency generation and parametric amplification enables to generate a wideband radiation in the range of 2-10 μm.
Enhancement of the Raman lidar sensitivity using overtones of vibrational-rotational Raman bands of oxygen or nitrogen as the reference signals
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Influence of the vibrational-rotational Raman bands of molecules of the main components of the atmosphere (oxygen and nitrogen) on the sensitivity of Raman lidar is considered. A method is proposed of using the first overtones of the vibrational-rotational Raman bands of oxygen and nitrogen molecules as the reference signals for the measurement of low concentrations of chemicals in the atmosphere by the Raman method.
Simulation of firebrands transport generated by the seat of fire
Oleg V. Matvienko,
Alexander I. Filkov
Show abstract
Physical and mathematical model of the seat of fire, taking into account the transport of firebrands from the combustion zone was developed. The results received in the study are tentative and can be used only for a qualitative description of the process. The motion of firebrands is mainly determined by the aerodynamic processes accompanying the combustion process. At the initial stage of the motion the medium and large size firebrands are transported by the rising flow in the direction to the upper boundary of the thermal column, then are trapped by a toroidal vortex and are transported from the combustion zone to the external boundary of the circulating flow, where they are deposited on the underlying surface. The maximum rise height of the particles transported from the peripheral area is smaller, and the transport range is greater compared to the particles transported from the central area. Large firebrands have a small specific surface area (the ratio between the particle surface area and volume) compared to small firebrands. As a result, the temperature of large firebrands during landing is above the critical one in contrast to small firebrands, which may initiate the ignition of the underlying surface and the formation of the secondary seat of fire.
Gas-analytic measurement complexes of Baikal atmospheric-limnological observatory
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The paper presents the present-day structure of stationary and mobile hardware-software gas-analytical complexes of Baikal atmospheric-limnological observatory (BALO) Siberian Branch Russian Academy of Sciences (SB RAS), designed to study the processes of gas exchange of carbon-containing gases in the “atmosphere-water” system, which are constantly updated to include new measuring and auxiliary instrumentation.
Crosswind and turbulence estimations from analysis of the images of light sources and topographical objects
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Simultaneous crosswind and strength of atmospheric turbulence estimations by the classical laser scintillation method and passive optical method from analysis of the light scattered by a natural or man-made topographic objects in natural daylight illumination conditions are presented. The passive sensing method does not require artificial light sources and lies in the formation of incoherent images of surrounding objects in the natural sunlight and analysis of distortion induced by turbulence between the object and the plane of observation The comparison of estimations of integral crosswind and index of refraction structure constant of air is realized at the same measuring optical path by both methods. Optical measurements of integral characteristics were accompanied by independent local acoustic measurements using sonic anemometers.
Quantitative comparison of the absorption spectra of the gas mixtures in analogy to the criterion of Pearson
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An approach to the reduction of the space of the absorption spectra, based on the original criterion for profile analysis of the spectra, was proposed. This criterion dates back to the known statistics chi-square test of Pearson. Introduced criterion allows to quantify the differences of spectral curves.
Mapping of the concentration of carbonaceous gases and fluorescent characteristics in the surface water of Southern Baikal
Show abstract
All our many-year studies of the gas-exchange processes were carried out at one observation site (BALO) in the littoral of Southern Baikal. Thus, the question about applicability of conclusions and estimates based on these data to the entire littoral zone inevitably arises. In 2014, we succeeded for the first time in organizing the combined research campaign for detailed mapping of the spatial variability of water characteristics in general for the littoral of southern Baikal. The spatial partial distribution of biogenic elements and the pressure of carbon dioxide and methane in the atmospheric surface layer and the surface water layer were studied in August 5-11 of 2014 from onboard of I.D. Papanin Research Vessel (RV). These studies covered, in section, the entire water area of the southern Baikal. The fluorescent characteristics, concentration of biogenic elements, partial pressure of carbon dioxide and methane in the surface water layer and the atmospheric surface layer were determined there. The continuous measurements of carbon dioxide and methane in the surface water and in the atmosphere in the course of the vessel were conducted by a mobile shipborne system, which was complemented with the flow-through fluorimeter. It has been found that the main features of fluxes and the value of dРg, as well as fluorescent characteristics are in a good agreement with the results of many-year measurements obtained in the BALO Observatory for the summer period.
Calculation of lidar echo signals during N2O and NO2 sounding alonge tropospheric paths in 3-4 μm range
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Possibilities of N2O and NO2 sounding in the 3–4 μm range along tropospheric paths are estimated on the basis of numerical simulation. The results are presented of search for information-bearing wavelengths and calculation of lidar echo signals during differential-absorption gas sounding.
OPO-laser system for atmospheric sounding in the mid-IR range
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A laser system is designed that provides for tunable generation of nanosecond radiation pulses in the 3–4 μm range. Optical block-diagram and specifications of the system are presented. The laser system as a part of a differential absorption lidar designed can be used for remote control of pollutant concentrations along surface atmospheric paths.
Informative wavelengths for trace atmospheric gas sounding with an opo-lidar in the 3-4 µm spectral region
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In this work, a search for information-bearing mid-IR wavelengths for HCl and HBr sounding with a differential absorption lidar based on an optical parametric oscillator has been carried out. Lidar echo signals have been calculated at the wavelengths chosen during sounding of gas components along vertical paths 0–5 km long.
Solving the inverse problem and estimation of H2O sensing possibility on short paths using a femtosecond laser source
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We consider the algorithms that implement a broadband (‘multiwave’) radiative transfer with allowance for multiple (aerosol) scattering and absorption by water vapor. In the spectral range of 0.9 – 0.98 μm, a closed numerical simulation of modifications of the supercontinuum component of a probing femtosecond pulse is performed. The ability of water vapor concentration measurements with white-light femtosecond lidar on the path 100–200 m is discussed.
Estimation of the ozone formation rate in the atmospheric boundary layer over a background region of Western Siberia
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The ozone formation rate in the atmospheric boundary layer (ABL) and the ozone inflow from the free atmosphere have been studied experimentally. The obtained estimates are based on the data of airborne sounding carried out over a background region of Western Siberia. As a result, it is obtained that the rate of ozone inflow from the upper atmospheric layers is only 20% of the rate of photochemical formation of ozone inside ABL. The vertical profiles of ozone flows in ABL have been additionally calculated based on the k-theory with the approach proposed by Troen and Mahrt. It has been shown in the calculations that the maximum of the ozone concentration in ABL is formed due to photochemical reactions from precursor gases.
Joint observations of the dynamics of atmospheric aerosol by means of aerosol and Doppler lidars on the coast of Lake Baikal
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Observations of the aerosol atmosphere by means of the "LOSA-M2" aerosol Raman lidar and the "Stream Line" pulsed coherent Doppler lidar were carried out in August 2014 near village Boyarsk (Baikal Lake coast). The wind field and its impact on the stratification and dynamics of the aerosol layers in the lower troposphere were studied under various synoptic conditions. The data of simultaneous observations of wave-like motions in the boundary layer of the troposphere by two lidars are presented.
Boundary layer of the troposphere of Western Siberia from the data of lidar measurements in Tomsk
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The results are presented of the study of planetary boundary layer of the atmosphere in the Western Siberian region, as well as retrieval of its optical and geometric characteristics from the data of lidar measurements. The basis of the study are 110 seances of sounding by means of the LOSA-S multi-frequency lidar in Tomsk (56°N, 85°E). Measurements of the optical characteristics in the boundary layer caused by transfer of aerosol from different geographic regions are considered. High values of the lidar ratio (66 sr) and the Angstrom exponent (1.62) are observed in the short-wave range in he boundary layer at transfer from Arctic. At the same time, low values of these parameters are characteristic of the transfer from Asia: lidar ratio 54 sr, Angstrom exponent 1.1, that is explained by different ratio of coarse and fine aerosol fractions in an air mass.
Experimental study of the interaction of THz radiation FEL with the atmosphere and water droplet aerosol
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The interaction of radiation of the Novosibirsk Free Electron Laser (FEL) at a wavelength of 130 μm in the atmospheric transmission window with a model aerosol cloud having the known droplet size distribution function has been studied experimentally. The experimental findings are compared with theoretical calculations obtained from solution of the lidar equation for the conditions of the experiment.
Thermal lens response in the two-component liquid layer
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The thermal lens scheme is proposed for a thin layer of two-component liquid in the cell which thickness is significantly less than the size of the beam. As a result, an exact analytical expression for the thermal lens response is derived, taking into account the thermal lens in the windows of the cell.
Investigation of features of processes Raman and fluorescence sea water depending on the time characteristics of the excitation radiation
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The forms and intensities of Raman lines and chlorophyll A fluorescence have been researched when excited at 532 nm, depending on the duration of the pulses of the exciting radiation. The duration of continuous operation ranged from emission to 120 fs.
Statistical approach to the analysis of the composition of multicomponent gas mixtures using absorption laser spectroscopy
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The possibility of the inverse spectroscopic problem solution for multicomponent gas mixtures based on the use of principal component analysis is discussed. The analysis revealed usefulness of principal component analysis to estimate the parameters of the components in a case of investigation of exhaled air samples from various groups of patients.
Concentration of nutrients in the water of Southern Baikal in summer
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Optical characteristics of Baikal water and their inter-annual, seasonal and diurnal variability depend on plankton composition, suspended particles of organic and inorganic substances, and dissolved chemical compounds. This work analyses the results of comprehensive studies on spatial distribution of nutrients (nitrogen, phosphorus, carbon, and silicon) in the water area of Southern Baikal performed in August 2014. The authors also compare the results of spatial measurements with the data of long-term observations in the littoral zone for summer conditions carried out at the Scientific Research Station of Limnological Institute of the Siberian Branch of the Russian Academy of Sciences.
Relative contributions of regional, urban, and local sources of atmospheric aerosol pollution in regions with different levels of anthropogenic load
Alexander S. Emilenko,
Andrey A. Isakov,
Vladimir M. Kopeikin,
et al.
Show abstract
Results of simultaneous round-the-clock measurements of the angular scattering coefficient and black carbon concentration carried out in 1984–2014 in the regions of Moscow, Moscow Suburbs, Caucasian Minvody, Beijing, and Xinglong Observatory are analyzed.
Behavior of trends of total ozone content according to data of ground-based (Tomsk: 56.48N, 85.05E) and satellite measurements
O. E. Bazhenov
Show abstract
We analyze positive trends of total ozone (TO) content over Tomsk, composed for different time intervals according to TO measurements with the use of М-124 ozonometer and employing TOMS/OMI/MLS satellite data. As a result of 2011 spring ozone anomaly in Arctic, the increasing TO trend of 1.09 DU/yr for the period of 1996 -2010 in Tomsk slowed down to 0.26 DU/yr for the period of 1996 - 2011. Afterward, the positive trend resumed recovery and became 0.65 DU/yr for the period 1996 -2013. In early 2014, the TO level lowered, primarily due to low temperatures in the Arctic stratosphere. Nonetheless, the positive TO trend for the period of 1996 - 2014 stayed at the level of 1996 – 2013 trend. At the same time, the annually average TO value had been 362 DU in 2014 versus 370 DU in 2013.
Investigation of the spectra of luminescence and Raman scattering in water and chlorophyll "a" excited by femtosecond laser pulses
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The Raman spectra of femtosecond laser pulses in distilled and tap water, and luminescence spectra of aqueous solutions containing dissolved organic matter, chlorophyll "a" and biological objects excited by ultra-short laser pulses was investigated.
Comparison of classification methods used for analysis of complex biological gas mixtures by means of laser spectroscopy
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The results of comparison of quality of two classificators – SVM (support vector machine) and SIMCA (soft independent modelling of class analogies) on model data contained profiles of absorbtion specra of exhalted air are presented. It is shown, that SVM classification results can be improved by preprocessing if input data with principal component analysis method.
Influence of laser pulse energy on emission lines intensity in the femtosecond laser-induced breakdown spectroscopy of iron in aqua solution
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The influence of pulse energy on the time evolution of the intensity of the continuum and emission lines of plasma generated on the surface of aqueous solutions of iron by focused radiation Ti: sapphire laser with a wavelength of 800 nm and pulse duration of 45 fs and a range of energy 3-7 mJ was investigated. The calibration curve for iron in water and 3-ó limit of detection of iron in water was obtained.
Inter-annual and seasonal variability of the diurnal behavior of aureole scattering phase function at the aerosol monitoring station of LOA IAO SB RAS in 2010-2014
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Inter-annual and seasonal variability of diurnal variations of the aureole scattering phase functions is analyzed. The data obtained by means of the completely automated aureole photometer with a closed scattering volume. Regular round-the-clock hourly measurements of the aureole scattering phase function were carried out in 2010-2014 at the Aerosol monitoring station of LOA IAO SB RAS in the region of scattering angles φ = 1.2 – 20° at the wavelength of 650 nm.
Analysis of the component composition of exhaled air using laser spectroscopy and canonical correlation analysis
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Canonical correlation analysis is adapted to the problem of determining the concentration of molecular components contained in samples of exhaled air. To solve this problem dealt with model spectra in form of linear combination of the absorption spectra of molecular components with unknown coefficients. The absorption spectra were calculated on the basis of databases HITRAN, HITEMP, GEISA. Application of canonical correlation analysis allows us to represent the spectrum of the mixture in the form of a vector whose coordinates are the proportion of the individual components in the mixture.
Detection of aerosol plumes from associated gas flaring by laser sensing
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A cycle of the TU-134 “Optik” aircraft-laboratory flights was carried out was carried out in the frameworks of investigations of radiative and climatic changes in sub-Arctic regions of Siberia. The vast aerosol plume was observed from onboard the aircraft using the data of laser sensing. Comprehensive analysis of the results of measurements of aerosol and gaseous components of the atmosphere and the accompanying data allowed us to reveal the nature of appearance of this plume from associated gas burning.
Spatiotemporal dynamics of the wind velocity variance from the data of acoustic sounding of the atmospheric boundary layer
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In the report spatiotemporal dynamics of the variance of three components of the wind velocity in the atmospheric boundary layer retrieved from measurements with a Doppler mini-sodar is analyzed. During measurements, the variances of the x- and y-components of the wind velocity were in the range 0.001 ≤ Dx, Dy ≤ 10 m2/s2; for the z-component 0.001 ≤ Dz ≤ 1.2 m2/s2. Their increase in the morning hours (at about 11:00, local time) and in the evening hours (from 18:00 till 22:00, local time) was noticed. This was explained by warming and subsequent cooling of the Earth surface accompanied by strengthening of motion of air masses. At night (from 00:00 till 5:00, local time), 0.01 ≤ Dz ≤ 0.56 m2/s2, which is in good agreement with the literature data.
Collision broadening effect upon tropospheric temperature calibration functions for pure rotational Raman lidars
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We present the general calibration function for temperature retrievals in the cloud-free troposphere using pure rotational Raman (PRR) lidars under the condition of the laser-beam receiver-field-of-view complete overlap. The function is derived within the framework of the semiclassical theory and takes account of the broadened by collision effects elastic backscattered signal leakage into the nearest (to the laser line) lidar PRR channel. The two simplest nonlinear special cases of the general calibration function are considered to be applied in the temperature retrieval algorithm. The vertical temperature profiles retrieved from nighttime lidar measurements in Tomsk (56.48°N, 85.05°E), on October 2, 2014, are given as an example. The measurements were performed using a PRR lidar designed in Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences (IMCES SB RAS) for lower-atmosphere temperature-profile retrievals.
Software for processing of experimental data on polarization laser sensing of high-level clouds
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Methodology for determination of the optical and geometric characteristics of clouds is described. Problems of processing data obtained in experiments on polarization laser sensing of the atmosphere are discussed. Technique for reduction of the phase matrices of cirrus obtained with the high-altitude polarization lidar developed at National Research Tomsk State University to the symmetry plane affixed to the preferred orientation of ice crystals in cirrus is described. The experimental data are compared with the data of numerical modeling of phase matrices in the physical optics approximation and meteorological conditions over the lidar at cirrus altitudes.
Using satellite radiometric and ground based lidar measurements for detection of cirrus clouds, containing ensembles of preferred oriented ice particles
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In this paper present an example of joint analysis of the data of high-level cloud sensing with a ground based polarization lidar of Tomsk State University and satellite radiometer MODIS.
Space-borne remote sensing of CO2 by IPDA lidar with heterodyne detection: random error estimation
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Possibilities of measuring the CO2 column concentration by spaceborne integrated path differential lidar (IPDA) signals in the near IR absorption bands are investigated. It is shown that coherent detection principles applied in the nearinfrared spectral region promise a high sensitivity for the measurement of the integrated dry air column mixing ratio of the CO2. The simulations indicate that for CO2 the target observational requirements (0.2%) for the relative random error can be met with telescope aperture 0.5 m, detector bandwidth 10 MHz, laser energy per impulse 0.3 mJ and averaging 7500 impulses. It should also be noted that heterodyne technique allows to significantly reduce laser power and receiver overall dimensions compared to direct detection.
The chemical and disperse composition of atmospheric aerosol in different layers of the troposphere background area of south of Western Siberia and its seasonal features on result of airborne sounding by Tupolev-134 "Optik"
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This paper presents the data of the vertical distribution of ion concentrations in aerosols and their seasonal characteristics obtained during the flights of the aircraft-laboratory Tupolev-134 "Optics" in 2011 – 2013 over the Karakan boron area in the southern part of the right bank of the Novosibirsk reservoir. The time duration of each flight is about 2 hours. Sampling on Petryanov filters AFA-CP-20 at heights and in the layers of 7000-5500, 4000-3000, 2000-1500 and 1000- 500 meters.
Sensing of low-contrast inhomogeneities in above-water atmosphere
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The possibility of using of lidar return for detecting of low-contrast irregularities in above-water atmospheric is discussed in this paper. Numerical calculation of lidar signals is carried out considering in the double-scattering approximation.
Structure of lidar return from cloud layer taking into account the double scattering
Valentina V. Bryukhanova,
Egor R. Poskrebyshev
Show abstract
The results of numerical calculation of lidar return considering double scattering from cloud layer with different microstructure based are discussed.
Influence of droplet cloud water content on the polarization characteristics of the double scattering lidar signal
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The paper discusses results of a numerical modeling of distribution of the intensity of double scattering lidar signal in the detection plane at different states of polarization of the probe radiation. We have found that the ratio of the degrees of polarization of the of the double scattering signal when probed with circularly and linearly polarized radiation is independent of the angle of view lidar receiving system. Shown that the dependence of this ratio on of the water content of clouds is linear.
Method of estimation of cloud base height using ground-based digital stereophotography
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Errors of the retrieval of the atmospheric composition using optical methods (DOAS et al.) are under the determining influence of the cloudiness during the measurements. Information on cloud characteristics helps to adjust the optical model of the atmosphere used to interpret the measurements and to reduce the retrieval errors are.
For the reconstruction of some geometrical characteristics of clouds a method was developed based on taking pictures of the sky by a pair of digital photo cameras and subsequent processing of the obtained sequence of stereo frames to obtain the height of the cloud base.
Since the directions of the optical axes of the stereo cameras are not exactly known, a procedure of adjusting of obtained frames was developed which use photographs of the night starry sky. In the second step, the method of the morphological analysis of images is used to determine the relative shift of the coordinates of some fragment of cloud. The shift is used to estimate the searched cloud base height.
The proposed method can be used for automatic processing of stereo data and getting the cloud base height. The report describes a mathematical model of stereophotography measurement, poses and solves the problem of adjusting of optical axes of the cameras, describes method of searching of cloud fragments at another frame by the morphological image analysis; the problem of estimating the cloud base height is formulated and solved. Theoretical investigation shows that for the stereo base of 60 m and shooting with a resolution of 1600x1200 pixels in field of view of 60° the errors do not exceed 10% for the cloud base height up to 4 km. Optimization of camera settings can farther improve the accuracy. Available for authors experimental setup with the stereo base of 17 m and a resolution of 640x480 pixels preliminary confirmed theoretical estimations of the accuracy in comparison with laser rangefinder.
On determination of formaldehyde content in atmospheric boundary layer for overcast using DOAS technique
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Formaldehyde (HCHO) is involved in a lot of chemical reactions in the atmosphere. Taking into account that HCHO basically undergo by photolysis and reaction with hydroxyl radical within a few hours, short-lived VOCs and direct HCHO emissions can cause local HCHO enhancement over certain areas, and, hence, exceeding background level of HCHO can be examined as a local pollution of the atmosphere by VOCs or existence of a local HCHO source. Several retrieval algorithms applicable for DOAS measurements in cloudless were previously developed. A new algorithm applicable for overcast and cloudless sky and its error analysis is briefly introduced by this paper. Analysis of our HCHO VCD retrieval for overcast shows that when one know the cloud base height, but doesn’t know cloud optical depth, the typical errors of HCHO total content retrieval are less than 10% for snow season, less than 5% for snow-free seasons, and reaches 40-45% for season with non-stable snow cover. In case one knows both the cloud base height and the cloud optical depth, the typical errors are about 5% for snow season, less than 2.5% for snow-free seasons, and are within about 10–30% for season with non-stable snow cover. Given above error estimations are valid if the HCHO layer is below the cloud base. The errors dramatically increase when HCHO layer penetrates into clouds in both cases. The first preliminary results of HCHO VCD retrieval for overcast are shown. The average difference of the HCHO VCDs for wind from Moscow megapolis and wind from few urbanized areas is about 0.8×1016 mol×cm-2 and approximately corresponds to estimates of influence of Moscow megapolis observed in clear-sky conditions.
Experimental research of fluorescence spectra of watercress stressed by lack or excess of watering
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Experimental laboratory investigations of the laser-induced fluorescence spectra of watercress were conducted. The fluorescence spectra were excited by a YAG:Nd laser emitting at 532 nm. The laboratory setup was described and fluorescence spectra of watercress in stressed states caused by lack and excess of water were presented. It was established that the influence of stress caused by lack and excess of watering is manifested in changes of fluorescence spectra.
Measurements of formaldehyde total content in troposphere using DOAS technique in Moscow Region
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Formaldehyde (HCHO) in the atmosphere is a product of oxidation of methane and other volatile organic compounds (VOCs), and so its content is an important index of air pollution by VOCs. HCHO has strong absorption cross-section in the UV spectral region and, hence, HCHO vertical column density (VCD) can be measured by remote optical methods including differential optical absorption spectroscopy (DOAS). Spectral measurements of scattered solar radiation are performed at Zvenigorod Scientific Station (ZSS, 55°41'49''N, 36°46'29''E) located in 38 km west from Moscow Ring Road by MAX-DOAS instrument since 2008.
For analysis of the HCHO variability we selected spectra taken in cloud free conditions. Version 1.2 of retrieval algorithm is used. It uses information on the surface albedo and the height of the atmospheric boundary layer inferred from a model. Data screening using color index was implemented. The obtained data quantify the Moscow megapolis influence on air quality at Zvenigorod by comparison of HCHO VCD for east and west wind directions. HCHO VCD for east winds is grater one for west winds for 0.5×1016 mol×cm-2 in average. Strong dependence of HCHO VCD on air temperature is noticeable in our data for air temperatures from +5 to +35°C. In different conditions of the atmosphere gradient of the temperature effect is about 1.1–1.2×1015 mol×cm-2×°C-1. The increase of the formaldehyde content with the increase of the air temperature can be caused by the HCHO formation from non-methane biogenic volatile organic compounds for which more emission is expected at higher temperatures.
Mobile hyper spectral optical complex for under satellite ocean research
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This paper presents the mobile complex to perform continuous measurements of chlorophyll-A concentrations and dissolved organic matter by the laser induced fluorescence method. The obtained data allow evaluating the state of the photosynthetic system of phytoplankton cells. In addition, the complex allows recording the CO2 gas analyzer data, the sea water saltiness sensors, pH, temperature, and solar illumination meter. The mobility this complex ensures a possibility working on different ships and under stationary conditions. The configuration of the complex can be promptly changed for solving the current problem by promptly adding or replacing various devices and sensors. The developed software integrates all devices into the complex. The enclosure of system allows use of conventional laboratory equipment, which is resistant to vibration, but not protected from the effects of the marine environment. Results of in situ measurements performed in Sea of Japan (Peter the Great Bay) by experimental setup are given.
Expedition automated flow fluorometer
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This paper describes an apparatus and operation of automated flow-through dual-channel fluorometer for studying the fluorescence of dissolved organic matter, and the fluorescence of phytoplankton cells with open and closed reaction centers in sea areas with oligotrophic and eutrophic water type. The step-by step excitation by two semiconductor lasers or two light-emitting diodes is realized in the current device. The excitation wavelengths are 405nm and 532nm in the default configuration. Excitation radiation of each light source can be changed with different durations, intensities and repetition rate. Registration of the fluorescence signal carried out by two photo-multipliers with different optical filters of 580-600 nm and 680-700 nm band pass diapasons. The configuration of excitation sources and spectral diapasons of registered radiation can be changed due to decided tasks.
Element composition of insoluble fraction of aerosols in snow in the vicinity of oil chemistry refinery (Pavlodar City, Kazakhstan) and petrochemical plant (Tomsk City, Russia)
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Tomsk petrochemical plant (Russia) and Pavlodar oil chemistry refinery (Kazakhstan) are the sources of air contamination in Tomsk and Pavlodar respectively. Therefore, it is very important to study the level of air contamination with particulate matter as well as ultimate composition of these particles. Disposable solid particles fall out to the snow cover, so snow is an accumulator of the particles. The article deals with the study results of dust load and concentrations of Br, Sb, La, Ce, Sm and Nd in insoluble fraction of aerosols in snow in the vicinity of Pavlodar oil chemistry refinery and Tomsk petrochemical plant. The instrumental neutron activation analysis was used for the ultimate composition detection. Results were shown that the dust load in the vicinity of Tomsk petrochemical plant is higher than in Pavlodar. We have detected high concentrations of La, Br and Sm in insoluble fraction of aerosols in snow in the vicinity of Pavlodar refinery and high concentrations of Sb and Ce in Tomsk. Moreover, we have detected high Br concentration in insoluble fraction of aerosols in snow of the vicinity of both plants. Gas burning on the flares of these enterprises is likely a potential source of Br. La to light lanthanoids ratio have shown La is of anthropogenic origin. In addition, enrichment factor estimation reflects an anthropogenic origin of La, Sm, Br, Ce and Sb as well. These elements might be emitted from different production facilities of the plants.
Optical properties of natural phenols in aqueous media
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Currently, the study of the photochemistry of natural phenols is relevant as it has a fundamental and a practical importance. The optical properties of natural phenols are studied: 3-methoxy-4-hydroxybenzaldehyde (vanillin) and 3- hydroxy-4-methoxybenzaldehyde (isovanillin), 4-hydroxy-3-methoxybenzoic acid (vanillic acid). The processes of proton transfer in the investigated molecules in ground and excited states under exposure to lamp and laser emissions are presented using the methods of electron spectroscopy and quantum chemistry.
Calibration and verification portable ceilometer
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In this article were consider problems of calibration and verification of a portable meter of height of the cloud base. We analyzed the characteristics of the operating conditions of calibration kits. Was reveal and provided the possibility of developing methods for the use of a compact calibration device. Based on the study, the authors proposed a technical way of implementation, formulated the basic characteristics, the sources and extent of error.
Comparison of different approaches to separate analysis of phytoplankton and CDOM contributions to ocean color forming
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Methods of empirical retrieval of chlorophyll – a and CDOM concentrations from hyperspectral ocean color data were described. We have considered cases of different relations between concentrations of these water constituents. Research area includes Japan Sea, East-China Sea, Okhotsk Sea, Barents Sea, Bering Sea, East-Siberian Sea and Chukchi Sea (water areas of different optical types) during the period from 2009 to 2014. Based on derived field data array, we created the method for building of regional empirical algorithms for concentrations of chlorophyll-a and CDOM retrieval taking into account differences of their contributions into water leaving radiance forming. In a similar manner, we have determined the most suitable spectral channels for the main satellite ocean color scanners. At the same time, we received concentrations of chlorophyll-a and CDOM with a help of tuning the semianalytical model for remote sensing reflectance (Rrs). Afterwards we carried out the quality assurance for the both approaches, comparing to shipboard data.
Dust pollution of the atmosphere in the vicinity of coal-fired power plant (Omsk City, Russia)
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The article shows the results of dust pollution level of air in the vicinity of coal-fired power plant of Omsk city on the base of study snow cover pollution. The samples were collected west-, east- and northeastwards at a distance of 0,75-6 km from the chimney for range-finding of dust emission transfer. The research findings have shown the dust load changes from 53 till 343 mg•(m2·day)-1 in the vicinity of power plant. The ultimate dust load was detected at a distance of 3-3,5 km. On the basis of asymptotics of equation solution for impurity transfer, we have made numerical analysis of dust load rate. With the usage of ground-based facilities and satellites we have determined the wind shifts in the atmospheric boundary layer have a significant impact on the field forming of long-term dustfall.
Multi-wavelength metal vapor laser systems for solving applied problems of atmospheric spectroscopy
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Results of a cycle of experimental investigations of a multi-wavelength metal vapor laser system based on original configuration of a multi-medium metal vapor laser source are presented. Novelty of our approach consists in that two gas-discharge active elements (on copper bromide and strontium vapors) are arranged in a common cavity, and each of them is pumped by an independent power supply unit, which allows them to be optimized independently for excitation conditions and thereby the output set of lasing wavelengths and their relative power distribution to be regulated. This makes the above-described system promising for a number of scientific and technological applications. The total output power of 11 spectral components lying in the range 0.43–6.45 μm reached ~17 W.
Investigation of the lasing characteristics of a barium vapor laser with pulse repetition frequencies up to 320 kHz for navigation
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Results of experimental investigations into the characteristics of a laser on self-terminating transitions of the barium atom with λ = 1499 nm are presented for high pulse repetition frequencies (PRF). The frequency-energy characteristics are investigated in the self-heating mode of laser operation. Record values of PRF for the barium vapor laser, equal to ~320 kHz, have been attained.
Detection of crude oil emulsions in the Bering Sea by the analysis of seawater color
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The paper presents the analysis of uncertainties between observed remote sensed reflectance spectra of seawater, with crude oil emulsions and oil dissolved fractions, and modeled remote sensed reflectance spectra of seawater without oil calculated from the fluorometric measurements of chlorophyll-a and dissolved organic matter concentrations carried out in the layer under oil pollution.
Calibration compact meteorological visibility sensor
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The article seeks to examine the possibility of calibration of the compact meter of meteorological visibility range, methods other than the method of direct comparison. During the analysis, authors for the first time in the literature show that it is possible to use formazine for this, as a means for calibrating the meter of meteorological visibility IMDV).
Optimization parameters of ceilometer
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The article is devoted to the optimization of the parameters of the meter of the height of the cloud base. The authors reveal the problem and possible ways to improve meter of the height of the cloud base. Particular attention is paid to improving the functioning of the device without changing the material base. Based on the analysis is determined by the wishes of the consumers' needs for additional product options.
On the effect of cloud microstructure on the polarization characteristics of double scattering lidar return
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The work is devoted to remote sensing droplet clouds by coaxial lidar. The results of numerical modeling of the distribution of polarization ellipse parameters of lidar returns in the double-scattering approximation are discussed. It is shown that the polarization state of sounding radiation transforms from a linear (or circular) to the elliptical at the study droplet clouds.
Numerical simulation of infrared radiation absorption for diagnostics of gas-aerosol medium by remote sensing data
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Calculated absorption spectra of the mixture of gases (H2O, CO, CO2, NO, NO2, and SO2) and aerosol (soot and Al2O3), contained in the exhausts of aircraft and rocket engines are demonstrated. Based on the model of gas-aerosol medium, a numerical study of the spectral dependence of the absorptance for different ratios of gas and aerosol components was carried out. The influence of microphysical and optical properties of the components of the mixture on the spectral features of absorption of gas-aerosol medium was established.
Lidar measurements of upper and middle atmospheric temperatures based on new configuration of multifunctional lidar of altitude sounding
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A number of night-time lidar soundings of the atmosphere were conducted in the period of 16-19 of March. The lidar had been modernized. Nowadays there is an opportunity to use four telescopes at the same time as well as to carry out measurements which are absolutely simultaneous within two altitude ranges which are from 0 to 30 km ( with the use of Raman scattering) and from 30-90 (with the use of Rayleigh scattering). The data help to define temperature profile up to 96 km as well as to obtain a continuous range of temperature profiles up to the altitude of 65-70 km with the time resolution at about one minute.
The special features of tree ring gas chronologies
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Stem wood is known to contain significant amounts of gases. However, literature data on the functional role of the gases are lacking. The results of our experiments show that porous wood structure is capable of annual accumulation (sorption) of the stem gas components that include H2O vapor and plant cell-respired CO2. This allows for development of additional chronologies to be used for gaining a deeper insight into the behavior of the stem gases. An analysis of the vacuum-extracted wood tree ring CO2 and H2O has revealed that the CO2 and H2O chronologies are associated with interannual variations in the total pressure of the gas components in the tree rings and are characterized by short-period cycles independent of tree age and by long-period variations with tree age. Our investigations led us to propose a procedure for using the CO2 content as a marker of year-to-year variations in the total pressure of the residual gas components found in wood tree rings.
Atmospheric Physics And Climate
Main physical processes and mechanisms responsible for the observable climate changes in the 20-21st centuries
G. A. Zherebtsov,
V. A. Kovalenko,
K. E. Kirichenko
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We discuss the issues of primary importance for understanding the nature of climate changes in the 20th century and main physical processes responsible for them. Special attention is paid to climate changes which occurred in 1943–1976 and 2000–2014. These periods exhibit the maximum increase in CO2 in the atmosphere, with virtually unchanged global temperature and its reduction in some regions. We study atmospheric and sea surface temperature effects of solar activity. The paper deals with results of the analysis of regularities and peculiarities of a tropospheric and sea surface temperature response to separate heliogeophysical disturbances as well as to long-term solar and geomagnetic activity variations. We also present results of the analysis of a change in sea surface temperature covering the time period 1854–2012 and their relation to solar activity variations. We find further evidence for the solar effect on climatic processes in the troposphere and ocean. We reveal a significant response in the major climatic characteristics, namely, surface air temperature and sea surface temperature (SST). It is established that the climatic response is characterized by significant space-time inhomogeneity, is regional and depends on the climate epoch. We discuss a role of wind stress and thermohaline circulation in the observable climate changes.
Numerical model of the urban heat island in a calm and stably stratified environment
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The RANS high close approach for the turbulent fluxes of momentum, heat and mass for simulating of the circulation structure and dispersion pollutant over the urban heat island in a stably stratified environment under nearly calm conditions is formulated. The turbulent fluxes of momentum − uiuj , heat −uiθ and mass −uic in this approach determined from the gradient diffusion type models with the turbulent kinetic energy (TKE), its spectral consumption (or dissipation), the temperature variance and the covariance for cθ as parameters which are obtained from transport equations. Such the RANS approach minimizes difficulties in the turbulent transport modeling in a stably stratified environment and reduces efforts needed for the numerical implementation of the numerical model. The simulation results demonstrates that the three-four equations RANS approach is able to predict the structure of turbulent circulation flow induced by the heat island that is in good agreement with the experimental data.
Spatial distribution of total column ozone and total column water vapor over European Russia during the spring and summer atmospheric blocks in 2010
S. A. Sitnov,
I. I. Mokhov
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With the use of data from AIRS satellite instrument the peculiarities in total column ozone (TCO) and total column water vapor (TCWV) fields associated with the spring and summer atmospheric blocking episodes over European Russia in 2010 were studied. In both of the episodes the extensive areas of negative TCO anomalies as well as those of positive TCWV anomalies were manifested over the blocking region. The local (1°×1°) negative TCO anomalies reached the values of -50 DU and -37 DU during the spring and summer blocks respectively, while the corresponding local positive TCWV anomalies attained 12 kg/m2 and 13 kg/m2. The revealed TCO and TCWV anomalies were mainly caused by the large-scale atmospheric circulation, associated with the omega blocks. In part, the TCO decrease could be the result of the photochemical destruction of ozone in the lower stratosphere due to water vapor advection.
Advanced radiometric complex for detection of radioactive release from Siberian chemical combine
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The paper states limited availability of the use of the automated radiation situation monitoring system and proposes radiometric complex as more reliable system in the case of an accidental release of the Siberian Chemical Enterprises.
Relation of tropical cyclone structure with thundersorm activity
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Synoptic and mesoscale cyclone systems over an ocean and seas are often accompanied by thunderstorm activity, which intensity and spatial distribution are modulated by the dynamic structure of these systems. The paper considers a method connecting the parameters of this thunderstorm activity with weather system structures over oceans and seas with mesoscale formation intensities and forms in these systems determined by driving wind vortex fields of scatterometers and by satellite images in visible and infrared ranges. On the example of separate tropical cyclones (TC) of 2005-2013, the relation of lightning discharge frequency and density in the TC area of influence and spatial distribution of driving wind vortex is shown. The work was supported by the Russian-American Grant RUG1-7084-PA- 13 in the area of fundamental researches of FEB RAS and CRDF.
Statistical structure of low stratiform clouds over the Siberian region
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The work presents the results of the statistical analysis of the characteristics of the low stratiform clouds, obtained according to the 8-term meteorological observations of 60 Siberian weather stations for the last 45 years (from 1969 to 2013). Researches of the amount and the base height of low stratiform clouds (Sc, St, Ns) have been conducted for four seasons. Wherein the statistics such as the average value (cloud amounts (balls)) and the frequency (%) for five gradations: 0, 1-3, 4-6, 7-9, 10 cloud amounts were used in the analysis of the amount of low-level stratiform clouds and the averages (km) and repeatability (%) for six gradations of the base height: 0.05-0.2; 0.2-0.4; 0.4-0.8; 0.8-1.2; 1.2-1.6; 1.6-2.0 km, complemented by the gradation "cloudiness" (0) were used in the analysis of the cloud base height.
Long-term changes of low stratiform clouds over the Siberian region
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The work presents the results of the analysis of climatic changes of the low stratiform clouds (Sc, St, Ns) over the territory of Siberia for the recent 45 years (from 1969 to 2013), performed by the data of 60 ground-based meteorological stations. The study of long-term changes of the amount and base height of low clouds were realized with using the curves of interannual variation, as well as linear trends and their rates.
The near real-time diagnostics of ionosphere parameters at the middle point of the radio path on the base of oblique sounding data
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The paper deals with techniques and algorithms of near real-time diagnostic software for estimating ionospheric parameters at a radio path midpoint based on data obtained from oblique sounding by a continuous chirp signal. We conducted a statistical analysis of precision characteristics of automatic determination of the critical frequency f0F2 at the path midpoint, using chirp ionosonde data.
The modeling of HF radio wave propagation characteristics during the periods of solar flares
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The results for modeling of HF radio waves propagation characteristics are given for the periods of solar flares 25.02.2014, 25.10.2013, 13-14.05.2013. The distance–frequency and amplitude-frequency propagation characteristics are calculated on the base of the complex algorithm which includes modules of ionosphere and plasmasphere global models and radio waves propagation model. The results of calculations were compared with experimental data of oblique ionosphere sounding obtained by chirp ionosonde on paths Magadan – Irkutsk, Khabarovsk – Irkutsk and Norilsk – Irkutsk.
The effects of space weather for HF propagation in the period of solar flare on 25 February 2014
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On the base of the space-distributed multipurpose chirp ionosonde effects of solar flare influence on conditions of HF signals distribution in the northeast region of Russia were registered on February 25, 2014. The absorption increase in D – ionosphere areas during flare due to splash in x-ray radiation was shown in disappearance of the signals corresponding to modes with multiple reflections from ionospheric layer both for the ionograms of oblique and vertical sounding. In the period of a magnetic storm on February 27, 2014 on the oblique sounding ionograms on paths Magadan – Irkutsk and Khabarovsk – Irkutsk in evening and night hours of local time, were observed additional signals with abnormally big delay. The amplitude relief of abnormal signals was characterized by strong diffusion, and frequencies exceeded the maximal observed frequencies of standard propagation modes.
The disturbances of ionospheric radio channel during magnetic storm on March 17-19, 2015
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The disturbances of ionospheric radio channel during 17–24 March 2015 magnetic storm are investigated. The heliospheric sources which caused the storm are considered. Based on space-distributed multipurpose chirp ionosonde data effects of geomagnetic disturbances influence on conditions of HF signal propagation are studied.
VLF station signals and radio noise intensity variations depending on solar activity registrated in Yakutsk during 2009-2014
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Diurnal variations of radio noise intensity (14.88 kHz) registered in Yakutsk in June 2009-2014 is 10 dB, March - 9 dB, September - 8.7 dB, December - 7.3 dB. Diurnal variations of intensity of radio station VLF signals, radio noise intensity and the number of lightning discharges in Yakutsk are compared. VLF noise variations in summer 5-10 UT defined local thunderstorm activity. The period 11-20 UT for receiving radio noise defined distant thunderstorm cells in Western Siberia, the territory between Hinggan, Buretsky and Stanovoy mountaines. Radio signals from these areas propagate in similar paths like signals Novosibirsk and Khabarovsk navaid stations. The attenuation variations from a solar activity minimum to the maximum are estimated. Taking into account the changes of propagation attenuation of 1.2 dB (signal Khabarovsk) from a minimum to a maximum of solar activity in July, the power of VLF radio noise at a minimum on 7.6 dB greater than at solar activity maximum.
Variations of the amplitude of lighting electromagnetic signals passing over epicenters of deep-focus earthquakes
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Observation of low-frequency radio signals may be used as a tool of remote monitoring of seismic disturbances in the lower ionosphere. In the case of using a low frequency radio signal the most informative parameter is a signal phase. When using natural low-frequency radio emissions - electromagnetic signals of lightning discharges (atmospherics), the variation of the signal amplitude is analyzed. For strong (magnitude greater than 5) and not deep-focus (focal depth is less than 50 km) earthquakes it is found that the effects of earthquakes and their precursors in the signals of atmospherics appeared in the form of increasing amplitude, whose duration is generally a few hours. In this work peculiar properties of the effects of manifestations in the signals of atmospherics of deeper earthquakes are considered on the example of the events in the Malaysian-Indonesian region.
Numerical simulation of vertical and oblique ionospheric sounding
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We study variation in the ionogram trace at a change in the propagation range. Addressed are the signatures of traveling ionospheric disturbances on ionograms.
Mathematical modeling for the forest fuel layer ignition caused by focused solar radiation flux
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Forest fuel layer ignition conditions analysis by focused flow of sunlight is lead. Scenarios of simulation corresponds to occurrence of forest fire as result of focused flux of sunlight influence on forest fuel layer. Scenarios calculations taking into account various intensity of radiation are lead. Recommendations on the further development of this component of determined model are submitted.
Dynamic effects of steep orography on cold front propagation in a stratified atmosphere
M. S. Yudin
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The present study is an extension of [3].It deals with calculation and comparison of velocities of gravitational currents over steep terrain in a stratified atmosphere. The propagation of a cold atmospheric front over orographic obstacles of various shapes is simulated with a 2D small-scale meteorological finite-element model. The front surface is explicitly described by a special equation. A time filter is used to suppress the non-physical oscillations. The effects of flow retardation and near surface blocking under steep orography are estimated. The upwind and downwind velocities calculated for typical values of the orography and stratification parameters are presented.
Height of layer of intense turbulent heat exchange under conditions of stable atmospheric stratification
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In the work, we consider estimates of the height of layer of intense turbulent heat exchange in stably stratified atmospheric boundary layer, made with the use of meteorological acoustic radar (sodar). Dependence of this height on temperature gradient is analyzed. Current temperature stratification of the atmosphere in the layer with height up to 1 000 m was determined with the help of МТР-5 meteorological temperature profiler.
The influence of natural magnetic field inhomogeneity areas of active geological faults on the dynamics of functional state of human brain
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The results of the expedition studies of the dynamics of the functional human state within the zone of active geological fault, which is characterized by abnormal parameters of the spatial distribution of values of the magnetic field vector are presented. It is shown that these geophysical modifications have pronounced effect on the fluctuations of the electrical activity of human brain.
The effect of variations of geomagnetic activity changing rate on trunk objects
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The frequency of occurrence of a certain level of the rate of change of geomagnetic activity can be expressed as a power law with an exponent of the order -1.7, and the probability of exceedance of a given level can be expressed by the law lg(P) = -0.0517 (dB / dt) – 0.1946. The largest high-frequency variations are noted during the recovery phase of magnetic bay and correspond to geomagnetic pulsations of the Pc5 range (a period of variations of 200-300 s). On a pipeline on these pulsations other high-frequency variations are imposed and they start earlier – from a maximum of bay of disturbance. It is noted the need of monitoring and forecasting of magnetic storms and recommendations on the allocation of periods, during which one cannot disable protection for preventive works.
Predictive map of geoelectric sections of North China and its application for the radiofields calculations
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Predictive map of geoelectric sections of the North China on a scale of 1 : 2 500 000, necessary for calculation of propagation of VLF-MF radiowaves, is constructed. Taking into account the layered structure of the underlying medium, this map is capable of increasing the accuracy of electromagnetic field calculations by 1.5-3 times as compared to the Morgan-Maxwell map. The methodology of the geoelectric mapping is described. The studies of electrical properties of layered media by combined radio and geophysical methods in a variety of natural and geological conditions, and the proposed method of geoelectric mapping have resulted in the construction of a new generation of maps showing the electrical properties of the underlying medium that account for the layered structure of the crust and have no analogues in the world.
Using of rank distributions in the study of perennial changes for monthly average temperatures
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The possibility of comparing the climatic data of various years with using rank distributions is considered in this paper. As a climatic data, the annual variation of temperature on the spatial areas of meteorological observations with high variability in average temperatures is considered. The results of clustering of the monthly average temperatures values by means of a recurrent neural network were used as the basis of comparing. For a given space of weather observations the rank distribution of the clusters cardinality identified for each year of observation, is being constructed. The resulting rank distributions allow you to compare the spatial temperature distributions of various years. An experimental comparison for rank distributions of the annual variation of monthly average temperatures has confirmed the presence of scatter for various years, associated with different spatio-temporal distribution of temperature. An experimental comparison of rank distributions revealed a difference in the integral annual variation of monthly average temperatures of various years for the Northern Hemisphere.
Spatial distribution of lightning strikes over North Asia
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The estimate on spatial distribution of lightning flash density over North Asia (40-80 N, 60-180 E) is presented from results of instrumental observations by the World wide lightning location network (WWLLN) during 2009-2014. There are two massive thunderstorm centers. The lightning density dependence on longitude and latitude caused by west air transfer and storm activity northward decrease is revealed. The region of Yakutia is considered individually.
Wind-stress effect on the relationships between sea surface temperature and geomagnetic activity
K. E. Kirichenko,
E. P. Belousova,
V. A. Kovalenko
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This paper deals with possible causes of broken relationships between geomagnetic activity (GA) and sea surface temperature (SST) in the regions where it is most prominent. We analyze data of 0/700 m ocean heat content, SST, and wind stress for the period 1948–2013. The aa index is used to describe geomagnetic activity. The zonal wind stress is demonstrated to have a significant effect on sea surface temperature in the regions under consideration. Increased fluctuations of heat content anomalies and change in wind stress structure have been noted since the 1976 climate shift.
Method for automatic absolute calibration of sodar measurement channels
A. P. Kamardin,
S. L. Odintsov
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We discuss a method for continuous absolute calibration of “Volna-4М” meteorological acoustic radar (sodar) measurement channels. Accelerometers, placed on paraboloids of sodar antennas, are suggested to use for automatic calibration. Results of testing the module of continuous sodar calibration are presented.
Search and tracking method of cloud fields on image
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In work the method and algorithm of data use for passive sounding of the earth (satellite remote sensing) are offered for estimation of speed and direction of wind. Presented the method of object search and tracking of the cloud fields in images.
Remote sensing of seismic disturbances in the lower ionosphere according to observations of lightning electromagnetic signals in Yakutsk
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Features of the remote sensing of seismic disturbances in the lower ionosphere are considered according to observation data of lightning electromagnetic signals passing over the earthquake epicenter, in Yakutsk. The technique has the ability to scan a large seismically active region or even several regions directly from one point, though in some azimuths there are limitations due to insufficiently high lightning activity. In last case, the receiving of signals at several spaced points is used.
The correlation of the maximum intensity of fluorescence with pigment characteristics of leaves of Betula pendula
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Using fluorimeter Junior PAM (Heinz Walz GmbH, Germany) the fluorescence parameters of leaves of Betula pendula are investigated. A linear dependence of the maximum fluorescence (Fm) of leaves from the ratio of total chlorophylls concentration to concentration of carotenoids is obtained. Such dependence is found for samples collected during the period of vegetation and for simultaneous selection of colored leaves.
Simulation of impact assesment of crown forest fires on boudary layer of atmosphere using software PHOENICS
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Mathematical model of heat and mass transfer of crown forest fire is used in this paper, which is developed on the base of experimental research data and laws and methods of mechanics of reacting media. The numerical calculation carried out using software PHOENICS for non stationary three dimensional case. K-Ɛ model of turbulence is taken into account. It is studied the influence of temperature and wind velocity in boundary layer of atmosphere on the turbulent kinematic viscosity coefficient value and distribution of temperature above the crown forest fire front.
Pilot project of measuring and computing system for mesoscale monitoring of atmospheric boundary layer
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Conception of design of measuring and computing system for monitoring atmospheric boundary layer is proposed. The system includes: stationary measuring complex consisting of four multiple-elevation ultrasonic weather stations and mobile measuring complex consisting of transportable weather station, touch probing system of weather data profile based on unmanned aerial vehicle and also Raman scattering gas analyzer, and new modification mercury gas analyzer.
Profiles of the structure characteristic of temperature in the atmospheric surface layer
V. A. Gladkikh,
S. L. Odintsov
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The results of measurement of the structure characteristic of air temperature C 2/T in the atmospheric surface layer at the three height levels in the summer period are analyzed. Ultrasonic anemometers-thermometers were used for the measurements. The vertical profiles of C 2/T are systematized, and empirical models are developed for some types of profiles.
Precipitation water stable isotope measurements and analyses in Middle and Polar Ural
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In this paper, we present results of precipitation (rain, snow) water stable isotope measurements, which were collected on two places. Measuring was made on laser spectroscopy analyzer PICARRO L2130-i equipped with liquid auto sampler. We describe method of sample collecting, preparing, measuring and continuing analysis of experimental data. Stored data include results of 177 samples measuring from Kourovka collected from November 2012 to March 2014 and 73 samples from Labytnangi collected from March 2013 to December 2013.
Large eddy simulation of turbulent flow and of pollutant transport in a street canyon
Alexander V. Starchenko,
Evgeniy A. Danilkin
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The work presents a non-steady three-dimensional eddy resolving model intended for the simulation of non-isothermal turbulent separation flows in street canyons. For a subgrid-scale turbulence parameterization, the Smagorinsky gradient model is used. The calculation results demonstrate the effects of pollutant source location, street canyon size, basic stream rate and wall temperature difference on air pollution in the canyon.
Using weather prediction data for simulation of mesoscale atmospheric processes
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The paper presents an approach to specify initial and boundary conditions from the output data of global model SLAV for mesoscale modelling of atmospheric processes in areas not covered by meteorological observations. From the data and the model equations for a homogeneous atmospheric boundary layer the meteorological and turbulent characteristics of the atmospheric boundary layer are calculated.
Investigation of snow cover dust pollution by contact and satellite observations
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The problems of reconstructing the snow cover pollution fields from dusting, point, linear and area sources according to ground and satellite observations are considered. Using reconstruction models, the methods of the combined analysis of the characteristic images of snow cover pollution haloes in the vicinity of sources of dust and contact data observations have been developed. On the basis of the numerical data analysis of ground monitoring and satellite imagery, the stable quantitative regularities between the fields of dust fallouts and the intensity of a change of tones of gray in the radial directions relative to the main sources are identified.
Structure of extreme precipitation field in Western Siberia
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The present paper introduces the results of analyzing the space-time structure of extreme characteristics of precipitation in Western Siberia. For each index, with the view of changes evaluation, differences between average values for periods 1951-1980 and 1981-2010 were calculated. The assessment of synchronicity in time and space with the use of factor and cluster analysis showed that changes in precipitation of Western Siberia are determined by global climate-forcing processes only by one-third. When taking into account the results of division into classes, the share of the explained variance increases to 40-60%. The performed classification confirmed an increase in synchronicity when decreasing the territory scale.
Measurements of methane and carbon dioxide fluxes on the Bakchar bog in warm season
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Data terrain-atmosphere fluxes of methane and carbon dioxide overseen for measurement campaign Plotnikovo-2014 on the bog’s Flux-NIES automatic complex (N56°51.29’ E82° 50.91’) in the warn season. Six vegetative groups on the bog’s surface were taken in comparison. Improvement precise method used to determinate the sensitivity for the gases analyzers and calculating of the CO2 and CH4 fluxes measured by automated chamber-based technique.
Fluorescence parameters of leaves of trees and shrubs during period of adverse weather conditions in Krasnoyarsk
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The effect of adverse weather conditions (AWC) on the fluorescence parameters of leaves Prinsepia sinensis, Amelanchier florida, Crataegus chlorocarca is obtained. However, significant changes in the fluorescence of the leaves of Acer negundo, Betula pendula under AWC were not observed.
Use of satellite information for analysis of aerosol substance propagation
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With satellite data on pollution of snow cover and data of meteorological observations, some fields of dust sedimentation from high chimneys of the Iskitim cement plant are studied. In the absence of snowfalls, a possibility to analyze of the areas of pollution, which are formed in time intervals from several days to several weeks in the vicinities of industrial enterprises, is shown.
Using WRF mesoscale model to restore temperature profile in atmosphere boundary layer in Tomsk
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In the paper, the possible use of a WRF mesoscale model for the detailed restoring of a temperature profile in the atmosphere boundary layer (ABL) during winter anticyclone is studied. The correctness of air temperature modeling as well as the possible use of a WRF model for predicting a vertical temperature distribution was shown.
Coherence of heart rate variability and local physical fields in monitoring studies
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Technological advances have led to a substantial modification of the physical fields of the environment, which could affect the status of living organisms under their constant exposure. In this study, the activity of human cardiovascular system under the influence of a complex natural physical environmental factors investigated. The study was conducted on a representative homogeneous sample (44 persons aged 19 to 22 years) by simultaneous monitoring of electrocardiograms and natural physical fields in Tomsk (geomagnetic field, meteorological parameters - temperature, pressure and humidity, surface wind speed, the parameters of the Schumann resonance - amplitude, frequency and quality factor of the first four modes in the range of 6 to 32 Hz, the power spectral density infrasonic background in the range of from 0,5 to 32 Hz). It was shown that among the set of parameters of physical fields present field that can resonate in the functioning of the human organism. The greatest coherence with heart rate variability detect variations eastern component of the geomagnetic field.
Climate modeling for Yamal territory using supercomputer atmospheric circulation model ECHAM5-wiso
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Dependences of monthly means of regional averages of model atmospheric parameters on initial and boundary condition remoteness in the past are the subject of the study. We used atmospheric general circulation model ECHAM5-wiso for simulation of monthly means of regional averages of climate parameters for Yamal region and different periods of premodeling. Time interval was varied from several months to 12 years. We present dependences of model monthly means of regional averages of surface temperature, 2 m air temperature and humidity for December of 2000 on duration of premodeling. Comparison of these results with reanalysis data showed that best coincidence with true parameters could be reached if duration of pre-modelling is approximately 10 years.
The research of the soil moisture satellite measurements accuracy depending on the underlying surface characteristics
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The work is devoted to the assessment of the possibility of using satellite data to determine soil moisture. The direct satellite observations were compared with the direct observations at the stations. Pearson correlation coefficient and the relative errors were calculated. The comparison of the data from the direct measurements of the soil moisture and satellite measurements showed that for the 52% of the stations the correlation coefficients exceeded 0.5.
Variations in vertical temperature profile of extratropical cyclones under different environmental conditions
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We study variations in the vertical temperature profile in central parts of warm and cold sectors of extratropical cyclones which emerge and evolve in the Northern Hemisphere during solar minimum. Dynamics of the vertical temperature profile during cyclogenesis over the land and ocean under quiet and disturbed geomagnetic conditions is analyzed. The classic cyclolysis occur under quiet geomagnetic conditions; the temperature decreases in the warm sector and increases in the cold one at a level up to 300 hPa. Under disturbed geomagnetic conditions, there is a slow increase in temperature in the cold sector. The warm sector of the cyclone is characterized by a small increase and stabilization of temperature, which perhaps results in slow cyclolysis and in increased lifetime of cyclones.
Variability of the atmospheric turbulence in the region lake of Baykal
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The estimations of the fried parameter according to micrometeorological and optical measurements in the atmospheric surface layer in the area of lake Baikal, Baikal astrophysical Observatory. According to the archive of NCEP/NCAR Reanalysis data obtained vertical distribution of temperature pulsations, and revealed the most pronounced atmospheric layers with high turbulence. A comparison of astronomical conditions vision in winter and in summer. By the registration of optical radiation of the Sun with telescopes, ground-based there is a need to compensate for the effects of atmospheric turbulence. Atmospheric turbulence reduces the angular resolution of the observed objects and distorts the structure of the obtained images. To improve image quality, and ideally closer to angular resolution, limited only by diffraction, it is necessary to implement and use adaptive optics system. The specificity of image correction using adaptive optics is that it is necessary not only to compensate for the random jitter of the image as a whole, but also adjust the geometry of the individual parts of the image. Evaluation of atmospheric radius of coherence (Fried parameter) are of interest not only for site-testing research space, but also are the basis for the efficient operation of adaptive optical systems 1 .
Methodology of monitoring the temperature and wind stratification in the atmospheric boundary layer based on multilevel ultrasonic measurements
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The methodology of the analysis of the temperature and wind stratification in the atmospheric boundary layer based on multilevel ultrasonic measurements is discussed. The equations for the calculations of the temperature and wind speed profiles from measurement data are presented.
Possible electron precipitation effects in the night time mid-latitude atmosphere
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We studied the 557,7 and 630-nm atomic oxygen emission responses to the solar wind sharp variations caused by shocks. For the analysis, were used optical and geomagnetic data for the Eastern Siberia and interplanetary magnetic field and solar wind data. The considered emission intensity was found to increase for some cases, whereas, in other cases, there were no responses during sharp variations in solar wind plasma speed and density. The presence or absence of the responses in the emissions was shown to be not related to the disturbance amplitude of the solar wind parameters. We suggested that the emission intensity increase might be caused by electron precipitation from the magnetic trap during the interaction between the solar wind shock and the magnetosphere.
Polarization characteristics of the Schumann resonance modes in Tomsk
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The article describes the experimentally determined distribution of ellipticity coefficient for the first three modes of the Schumann resonances (SR) for different seasons in 2014. Established the presence of seasonal variation of the frequency of occurrence for different types of polarization of the first three modes SR. It is shown that the frequency of occurrence of elliptical polarization for different modes of SR is about 70–80%. Circular polarization - a very rare event, the frequency of its occurrence is less than 1% for every season of the year.
Variations of the electric field of the monitoring data in the city of Tomsk
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The paper presents the daily variations of the electric field in the period from March 2012 to February 2013, received by the monitoring data in the city of Tomsk. Also in the article the interpretation of the results.
Statistical assessment of characteristics of acoustic signals from land explosions
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The possibility of the estimation of ground explosions energy using infrasound monitoring data for 100-300 km distances is discussed. Infrasonic signals energy from ground explosions is estimated using different methods.
Calculation of the Siberian subarctic rivers runoff in the XXI century
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The paper discusses the results of calculations by the linear reservoir model of the climatic river runoff for the subarctic Eastern Siberia region. For the verification of the model the measurements data as well as the MERRA reanalysis data for the XX century were used. For the XXI century calculations by the data of the INM, CRNM, GFDL, HadGEM, MIROC5, MPI models of the scenario RCP 8.5 of the Project CMIP5 IPCC were done.
Study of atmospheric surface layer electrical processes in case of varying intensity rain
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The variations of the surface potential gradient, and positive and negative air electric conductivities during the passage of the series of atmospheric fronts, which were accompanied by the showers and continuous rains, are investigated. According to the analysis of experimental data, the distortion of the related variations of the potential gradient and air electric conductivities occurred during rain. The value of this distortion depends on the rain type and the rain rate.
Results of magnetic measurements of ELF fields in Tomsk for the period 2013-2014
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The paper describes a method of magnetic measurements of natural electromagnetic fields ELF range. The results of the analysis of the frequency characteristics of fashion Schumann resonances in a suburban area in the seasonally-daily cycle of observations.
Lidar observations and transfer of stratospheric aerosol over Tomsk in summer period
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The analysis of the stratospheric aerosol origin was carried out by the method of Lagrangian particle trajectories. Stratospheric aerosol was registered by lidar sounding of atmosphere above Tomsk in 2008-2013 in summer time. The analysis of the results had shown that the aerosol content at altitudes of 13-125 km with maximum at 16-18 km can be associated with aerosol transfer from tropical stratospheric reservoir.
Climate changes in the Southern Hemisphere subtropical jet stream during the second half of the XX century - the beginning of XXI century
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Subtropical jet stream is a narrow stream of strong wind at 200-hPa level, characterized by large vertical and horizontal wind shift and one or more maxima speed, reaching values of 70-100 m/s. The subtropical jet stream is located on the border of the "warm" and "medium" temperature zones in the Southern Hemisphere. The average annual trend of wind speed of the Southern subtropical jet stream is significant and is equal -0.47±0.10 m/s per decade. The subtropical jet stream is shifting southward (0.87°S ±0.08°S per decade) in the Southern Hemisphere.
Comparative analysis of the dynamics of biogenic elements and direction of carbon dioxide fluxes between the atmosphere and the water surface in Lake Baikal and in bays of the Sea of Japan.
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Measured СО2 flux between the atmosphere and water and the dynamics of biogenic elements in cardinally different water basins: Lake Baikal and coastal maritime conditions, are compared. We conduct regular cycles of combined observations at the Southern Baikal shore for different seasons at the Baikal Atmospheric-Limnological Observatory (BALO). The measurements under maritime conditions were conducted at the stationary station of the Far East Branch of the Russian Academy of Sciences at Schultz Cape in the period of October 6-10 of 2012 and October 7-13 of 2013, as well as in 2014 a cycle of investigations on the assessment of spatial variability was carried out. The most remarkable distinctive feature of the content of dissolved gases and their flux under maritime conditions (Far East) is the permanent sink of carbon dioxide from the atmosphere onto the water surface. At Lake Baikal in this period, we observed the pronounced diurnal dynamics characterized by the daytime sink and nighttime emission of СО2 into the atmosphere.
Remote sensing of potential aircraft icing areas
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Remote sensing technique of detection of potential aircraft icing areas based on temperature profile measurements, using meteorological temperature profiler, and the data of the Airfield Measuring and Information System (AMIS-RF), was proposed, theoretically described and experimentally validated during the field project in 2012 - 2013 in the Tomsk Bogashevo Airport. Spatial areas of potential aircraft icing were determined using the RAP algorithm and Godske formula. The equations for the reconstruction of profiles of relative humidity and dew point using data from AMIS-RF are given. Actual data on the aircraft icing for the Tomsk Bogashevo Airport on 11 October 2012 and 17 March 2013 are presented in this paper. The RAP algorithm and Godske formula show similar results for the location of spatial areas of potential icing. Though, the results obtained using the RAP algorithm are closer to the actual data on the icing known from aircraft crew reports.
Results of temperature measurements in the upper troposphere and the middle atmosphere by means of a lidar using the channels of Rayleigh and Raman scattering
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The lidar complex used combined optical sensing method for the lower and middle atmosphere. The method is based on the reception signal Rayleigh (elastic molecular scattering of light at a wavelength of 532 nm) and Raman (radiation first vibrational-rotational transition of molecules of nitrogen cents a wavelength of 607nm when excited by laser radiation in the latter wavelength of 532nm) light scattering. Using Raman channel possible to eliminate the distorting effect of the aerosol on the heights of its location (up to 25km) for the temperature measurement accuracy. With the simultaneous measurement of signals in the two receiving channels received extended temperature profiles in heights from 7 to 60 km, covering the upper troposphere and middle atmosphere. A good agreement with satellite data and upper-air measurements, as well as model representations.
Modernization of the Small Lidar Station of IAO SB RAS
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Modernization of the instrumentation part of the Small Lidar Station of the V.E. Zuev Institute of Atmospheric Optics SB RAS (SLS) from the beginning of its work to present date is considered.
Forecast of extreme weather conditions that promote aircraft icing during take-off or landing
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This work presents the results of forecasting meteorological conditions that promote aircrafts icing in the atmospheric boundary layer; the forecasting results were obtained based on mesoscale meteorological model TSU-NM3. Godske formula which is based on the calculation of saturation temperature above ice, NCEP method, and statistical method of Hydrometeorological Centre of Russia were used as criteria of probability of aircraft icing during take-off or landing. Numeric forecast results were compared with physical observations made in the atmospheric boundary layer in October 2012 at the Tomsk airport. A good agreement obtained provided an opportunity to be certain about the above approach viability.
Studying the variations in background aerosol loading of the stratosphere in 2014
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The report analyzes the experimental data on the variability of vertical-temporal structure of the aerosol produced in the complex lidar station altitude atmospheric sounding IAO SB RAS in 2014. The primary data used for the analysis of an array of data from 67 combined signals accumulated in individual nights, probed range in height from 15 to 50-60km, the spatial resolution was 192m.
Filtration and assimilation of soil moisture satellite data
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This paper presents two data filtration methods. These methods are used for filtration of satellite soil moisture measurement data. A comparison with in-situ soil moisture measurement data shows an improvement in data quality after application of the filters. First results of satellite data assimilation with a global model of numerical weather forecasting are given.
Development of a software for control of the Lidar complex at the IAO SB RAS small Lidar station
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The problems are discussed in the wide circles of the scientific community in the end of the last and in the beginning of present century, related with climate change on both global and local scale. The complicated question of changing climatic and ecological systems under the effect of natural and anthropogenic factors requires the development and creation of atmospheric aerosol thermodynamic and spatial-temporal models, development of network of both ground-based and space-based services for monitoring of the atmosphere on a global scale [1, 2]. Measures on collection of great amount of data lead to the need of development of not only technical side of the solution to the problem, but also methodological, algorithmic and software. The last decade is marked by the widespread introduction of computer technology into science and increase of its consumer features, such as speed, volume of RAM and cash memory, as well as the ability of high-quality displaying the data. Therefore, the final item in the development of automation of the experiment and application of mathematical methods is the development of the software tools. Software should carry the main load in the processing and simulation of an experiment, and to be a link between theoreticians, developers of the processing methods and models of physical processes and experimentalists
Influence of atmospheric turbulence scales
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At the paper are doing the possible approach for analysis of turbulence scales effect. We are doing he approach the explaining the difference of data of acoustical and optical measuring methods of turbulence level estimations.
Lidar studies of specific manifestation features of stratospheric warming in winter of 2014-2015
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Studying the atmospheric thermal regime is one of important applications of lidar technologies. These studies in monitoring mode in Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences had been initiated since 1994 and continue until presently. A special attention is paid to studying the manifestations of sudden disturbances in the middle stratosphere, caused by wintertime stratospheric warmings (SWs). Reader can be acquainted with results on the subject in works [1-3]. In this paper, we present studies of SW during winter of 2014-2015.
Analysis of observations and results of numerical modeling of meteorological parameters and atmospheric air pollution under weak wind conditions in the city of Tomsk
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The results of calculation of meteorological parameters using a meteorological model, TSU-NM3, as well as prediction of some indices of atmospheric air pollution in the city of Tomsk obtained from a mesoscale photochemical model are presented. The calculation results are compared with observational data on the atmosphere and pollutants.
A method for direct variational data assimilation from various observing systems
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A new method for the joint use of mathematical models and heterogeneous data from various monitoring systems for ground and space based assets, including the sequence of images, is presented. The method is based on variational principles with weak constraints. The algorithm for its implementation allows us to use images in the problems of prediction and reconstruction of multidimensional fields of the state functions.
Levenberg-Marquardt method with simultaneous calculations of averaging kernels and errors for methane retrieval from IASI spectra
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Levenberg-Marquardt method parameter selection for methane vertical profile retrieval from IASI/METOP spectra is presented. A modified technique for iterative calculation of averaging kernels and a posteriori errors for every spectrum is suggested. Known from literature method is expanded for the case of absence of a priori statistics for methane vertical profiles. Software for massive processing of IASI spectra using is developed. Effect of LM parameter selection on averaging kernel norm and a posteriori errors is illustrated. NCEP reanalysis data provided by ESRL (NOAA, Boulder, USA) were taken as initial guess. Surface temperature, temperature and humidity vertical profiles are retrieved before methane vertical profile retrieval.
Health risk assessment of urban population exposure to contaminants in the soils of the Southern Kuzbass
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This study concerns the human health risk due to exposure of Co, Cu, As, Mn contained in soils of the Southern Kuzbass, where the coal industry is developed. Soil samples of 200 were taken in Mezhdurechensk - city with intensive coal mining and processing industries. The content of heavy metals in samples were determined using the electron spectroscopy. Several samples were also investigated by methods of the instrumental neutron activation analysis (INAA) and the inductively coupled plasma mass spectrometry (ICP-MS). With regard to the effects of heavy metals on the adult population health the total Hazard Index (HI) for ingestion and inhalation routes was 0.87×10-1 and 7.8×10-1 respectively. According to the contribution of Co, Cu, As, Mn to the total HI the elements form the decreasing series Mn (0,42-0,50)> Co (0.18-0.20)> Cu (0,13-0,19 )> As (0,05-0,09). These chemical elements are present in the organic and inorganic forms in coals and coal wastes. Ranking the city territory has shown that administrative districts have different HI values (8.4 10-1 - 8.8 10-1). When analyzing the human health risks of coal mining and coal-processing enterprises the impact of heavy metals as components of coals and combustion products should be taken into account.
Resonance scattering at excited atoms and ions of the upper atmosphere as a possible mechanism for ionosphere investigations
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According to the results of lidar observations in 2014, new experimental data are presented. They confirm the possibility of correlation of lidar signals backscattering at the wavelength of 532 nm with the parameters determining plasma content in the nighttime ionospheric F2 layer. The possibility of application of the lidar method in ionosphere investigations is discussed. The physical basis of this method may be the resonance scattering on the exited atoms and ions of the upper atmosphere.
The study of turbulence and optical instability in stably stratified Earth's atmosphere
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It is shown that atmospheric turbulence is not suppressed completely in strongly stably stratified conditions when Richardson's number exceeds its critical value. It is worth to note that airflow is laminar according classical ideas of the turbulence theory when Richardson's number values are supercritical. It is shown that in the stably stratified atmospheric surface layer under conditions of large vertical temperature gradients and low wind speeds, atmospheric turbulence is often characterized by intermittent structure and in some parts of space intensity of fluctuations can reach high values. The results of experimental investigations of optical instability conducted out along the horizontal path in the stably stratified atmospheric surface layer are discussed.
Modeling of hydrodynamics of water-methane heterogeneous system
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To study the behavior of heterogeneous methane-water system, a mathematical model describing the joint processes of hydrodynamics, transport, and transformation of methane in a deep freshwater body is used. There are three phases of methane in the system: solid (hydrate), gaseous (bubbles) and dissolved in water. We discuss the physical origin of phase transitions in the specific conditions of Lake Baikal and possible mathematical formulations of problems. Some preliminary results of calculations are presented.
Direct variational data assimilation algorithm for atmospheric chemistry data with transport and transformation model
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Atmospheric chemistry dynamics is studied with convection-diffusion-reaction model. The numerical Data Assimilation algorithm presented is based on the additive-averaged splitting schemes. It carries out ''fine-grained'' variational data assimilation on the separate splitting stages with respect to spatial dimensions and processes i.e. the same measurement data is assimilated to different parts of the split model. This design has efficient implementation due to the direct data assimilation algorithms of the transport process along coordinate lines. Results of numerical experiments with chemical data assimilation algorithm of in situ concentration measurements on real data scenario have been presented. In order to construct the scenario, meteorological data has been taken from EnviroHIRLAM model output, initial conditions from MOZART model output and measurements from Airbase database.
The long-term variations of critical frequency in the F2 region of ionosphere and solar activity
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The work is devoted to the analysis of ionospheric parameters on the basis of the National Geophysical Data Centre (NGDC). There is a quantitative assessment of the long-term variations in the critical frequency of F2 region of the ionosphere as a function of an 11 year old cycle of solar activity.
Mathematical modeling of the receiving antennas of Ionosonde "TOMION"
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The work is devoted to modeling and defining optimal performance phased array Ionosonde «TOMION».
History of Tomsk Ionospheric Station development
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In 1936 regular researchers of the ionosphere started a Ionospheric Station in Tomsk (Russia).By the year 2016 it will be 80 years old. This article is devoted to this remarkable event.