Measurement of air vertical motion in the atmosphere by aerosol micro pulse lidar

Recently, the micro pulse lidar (MPL) has been frequently used for long-range observation on the atmospheric aerosol distribution up to the heights of 20 km or even farther. The MPL systems are relatively compact and reliable, and also require a short measurement time of a few minutes to obtain profiles of the distribution of the aerosol scattering coefficient in a cloudy and a clean atmosphere. With the extension of such opportunities, a statistical spectral method of the processing of the temporal arrays of profiles from echo signals of a MPL system was tested with the purpose of estimation of the vertical speed of an inhomogeneously moving aerosol in the troposphere and stratosphere. Basically, it is possible when the aerosol heterogeneity has a large size on the horizontal direction in comparison with the size on a vertical direction. Besides, the speed of vertical motion of air is typically one or two orders of magnitude slower than the horizontal velocity. Usually, aerosol has the same velocity with atmospheric air. Thus, it is possible not to take into account the speed of the horizontal movement of air. In this case, the characteristic time for averaging must be a few hours. The main idea of the work is to use the spectral Fourier analysis (FFT) of the time series of lidar return fluctuations at different heights.