Investigation of vertical wind characteristics of convection over a tropical location

Abstract

Vertical wind plays a crucial role in convection and cloud processes, transporting mass and momentum to the upper troposphere and stratosphere. Very high frequency wind profiling radars uniquely measure vertical wind velocity profiles under all weather conditions. This study examines ten years of observed vertical wind using wind profiler over a tropical station, Gadanki, to characterize draft cores and vertical wind patterns pertinent to convection episodes. Downdraft cores (764) outnumber updraft cores (484), with core properties following a lognormal distribution favoring stronger updraft intensities. Over 70 % of updrafts and 90 % of downdrafts have maximum value below 5 m s⁻¹, and only 12 % persist beyond 15 min. Updrafts show significant vertical variation above 5 km, unlike downdrafts. Among convective types—shallow, congestus, and deep—congestus are most frequent, while deep cores are less common. The velocity difference between shallow and deep updraft cores is 7 m s⁻¹ as compared to 1.64 m s⁻¹ for downdrafts, indicating predominantly stronger updrafts overall. During the southwest and northeast monsoon seasons, weaker updrafts and downdrafts occur at lower altitudes, gradually increasing with height. Pre-monsoon updraft profiles exhibit prominent double peaks near 5.0 km and 13.5 km altitude, whereas, during the monsoon and post-monsoon periods, single peaks prevail around 10 km and 11 km, respectively. Seasonally, congestus cores (∼20 %) exhibit the highest occurrence in the post-monsoon and the lowest in the pre-monsoon. The observational vertical structure of convective dynamics over a tropical station unravels the realistic updraft and downdraft core magnitudes pertinent to tropical convection.