Nature of precipitation and activity of cumulus convection during the 1991 meiyu season of changjian-huaihe river basin

摘要

Seasonal variability regarding the nature of precipitation and the activity of cumulus convection during the 1991 Meiyu season of Changjing-Huaihe River Basin(Jianghuai)has been investigated by calculating apparent heat source/apparent moisture sink and analyzing TBB(cloud-top blackbody radiation temperature)data. It is found that three periods of strong ascending motion during the Meiyu season lead to three episodes of heavy rain, and the latent heat due to the precipitation is of the sole heat source of the atmosphere. The nature of precipitation shows distinct seasonal variability, from frontal precipitation of the first episode to the extremely strong convective precipitation of the third episode.