Atmospheric subsidence and the surface temperature variability in the pre-monsoon month over a semi-arid north peninsular Indian station: A case study

Abstract

Variability in maximum temperature in the month of March 2004 over Pune, a station representative of semi-arid re-gion of north peninsular India, has been studied. The vertical wind velocity data measured by UHF wind profiler, installed at Pune (18.31ºN, 73.58ºE) has been utilized. Hourly averaged vertical wind velocity profiles were obtained four times a day, on a three hourly basis from 0800 to 1700 hrs IST (Indian Standard Time) in March 2004. The vertical velocity is found to have a typical mean and standard deviation of 10 and 15-20 cm/s, respectively. The mean structure of the vertical distribu-tion showed predominately upward motion extending up to 2-3 km and predominately downward motion in the 3-6 km lay-ers. After removing the effects of radiative and advective heating, the anomalies in the maximum temperature over Pune are found to be statistically related with the depth of the atmospheric column over which the subsidence occurs.