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Proceedings Paper

Measurement of slow air vertical motion in the atmosphere by micropulse lidar
Author(s): Igor Alexandrov Razenkov; Hyungki Cha; Dukhyeon Kim; Jongmin Lee
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Paper Abstract

Idea of this work is to use the spectral Fourier analysis of time series of lidar return fluctuations between two different heights. Formally, fluctuating signals from two heights can be considered as an input and output signal of a linear system. If the system is linear, the mutual phase spectrum is linear function of temporal frequency. We have used a simple and reliable method to estimate wind velocity, and the algorithm is to fix the frequency at which the phase spectrum reaches the value +/- (pi) or jump through zero of mutual phase spectrum function. The sign of phase angle means the direction of movement, i.e. upwards or downwards. The algorithm is applied to the real data of Micro Pulse Lidar (MPL) system. The MPL data provide an array of aerosol scattering coefficients up to the heights of 20 approximately 30 km with the sampling frequency of approximately 20 cycles per hour. In order to determine the vertical speed, the average time interval about 3 hours is required. The statistical reliability at single height is obtained by averaging several heights with the resolution of 1 km interval. From a spatial-temporal map of vertical motion in cloudy conditions, we find that there are downward movements of the air under the cloudy layers. That is the typical characteristics of cloud because when it moves down, cloudy drops are evaporated and also air temperature is lower. This dynamics promotes further acceleration of this process.

Paper Details

Date Published: 19 November 1999
PDF: 7 pages
Proc. SPIE 3983, Sixth International Symposium on Atmospheric and Ocean Optics, (19 November 1999); doi: 10.1117/12.370507
Show Author Affiliations
Igor Alexandrov Razenkov, Institute of Atmospheric Optics (Russia)
Hyungki Cha, Korea Atomic Energy Research Institute (South Korea)
Dukhyeon Kim, Korea Atomic Energy Research Institute (South Korea)
Jongmin Lee, Korea Atomic Energy Research Institute (South Korea)


Published in SPIE Proceedings Vol. 3983:
Sixth International Symposium on Atmospheric and Ocean Optics

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