Lidar observations of atmospheric internal waves in the boundary layer of the atmosphere on the coast of Lake Baikal

Abstract

Atmospheric internal waves (AIWs) in the boundary layer of atmosphere have been studied experimentally with the use of Halo Photonics pulsed coherent Doppler wind lidar Stream Line. The measurements were carried out over 14-28 August 2015 on the western coast of Lake Baikal (51°50'47.17" N, 104°53'31.21" E), Russia. The lidar was placed at a distance of 340m from Lake Baikal at a height of 180m above the lake level. A total of six AIW occurrences have been revealed. This always happened in the presence of one or two (in five out of six cases) narrow jet streams at heights of approximately 200 and 700m above ground level at the lidar location. The period of oscillations of the wave addend of the wind velocity components in four AIW events was 9min, and in the other two it was approximately 18 and 6.5min. The amplitude of oscillations of the horizontal wind velocity component was about 1 m s-1, while the amplitude of oscillations of the vertical velocity was 3 times smaller. In most cases, internal waves were observed for 45min (5 wave oscillations with a period of 9min). Only once the AIW lifetime was about 4h.