Use of the BSA-lidar for the turbulent spatial and temporal variability in the atmospheric surface layer

摘要

An aerosol lidar designed specifically for measurement of the backscatter amplification (BSA) was used in a field experiment, and the procedure for information processing was proposed, which allows the obtained data to be presented in the form convenient for analysis. The BSA-lidar records the value of the relative amplification coefficient, which is proportional to the intensity of atmospheric turbulence. The spatial profile of the backscatter amplification coefficient is the monotonically increasing function, the first derivative of which allows one to localize zones with intense turbulence. Construction of range-time images (RTI) of the derivative of the amplification factor gives a comprehensive picture of the location of such zones and their temporal dynamics. The experiment was conducted in the winter season under urban conditions. An image jitter sensor operated at the same path simultaneously with the lidar for the independent control. It has been found that the night behavior of the amplification factor differed from the daytime one by its volatility, and night values of this factor could exceed twofold the daytime level, increasing up to 3. Maximal gradients of the amplification factor equal to 4 km"1 have been obtained.