Vertical variations of rain intensity in different rainy periods in and around Bangladesh derived from TRMM observations

摘要

In this paper, differences in rain intensity in and around Bangladesh during various rainy periods are described. The data were obtained from tropical rainfall measuring mission (TRMM) -2A25, -31342 and -3B43. The version 5 (V5) 3B42 daily products overestimated rainfall in pre-monsoon and post-monsoon periods but underestimated it in the monsoon period compared with rain-gauge data. The version 6 (W) daily products reduced the over- and underestimation ofrainfall. On the basis of the analysed rainfall characteristics in different rainy periods, the 2A25 data was analysed to reveal the vertical variations of rain intensity. Pre-monsoon rainfall was characterized by convective rain with strong intensity upto high altitudes and high echo tops that usually occurred over land and not over the Bay of Bengal. In contrast, during monsoon, intense rain occurred over the Bay of Bengal and land; however, the existence of strong and high echo tops was less significant than that during the pre-monsoon period. The radar echo tops and the height of strong rain intensity measured in the post-monsoon period were lower than those obtained in the monsoon period. Copyright (c) 2007 Royal Meteorological Society.