Diurnal observation of the deep convective precipitation system and the associated gravity wave signatures using 206.5 MHz VHF radar over the central Himalayas

Abstract

With the aim to explore the dynamical behavior of the lower atmosphere during precipitation in monsoon season over Himalayan region, diurnal observation with ARIES Stratosphere Troposphere radar were conducted from September 23 to 24, 2020. Development and evolution of the precipitation system was studied through the derived high resolution wind profiles from radar as well as from radar backscattered power and spectral width. A burst of gravity wave of 8 −10 minutes in period was detected before the precipitation in the mid-troposphere. Similarly gravity waves signatures of 25 minute period were detected among the updraft and downdraft couplet in the upper troposphere and lower stratosphere region during convective precipitation. Overall depletion of turbulent echo power is detected and significant reduction of about 6 dB in radar SNR in noticed around tropopause height during convection. Significant enhancement of horizontal momentum flux noticed during convection period at all height levels.