Different Physical Properties of Summer Precipitation Clouds over Qinghai-Xizang Plateau and Sichuan Basin

Abstract

The statistical discrepancy of physical properties of summer precipitation clouds over the Qinghai-Xizang Plateau,Sichuan Basin and their transition region were analyzed,based on July and August Cloud Sat products from 2008 to 2010. At the same time,four examples from Cloud Sat,FY- 2D TBB data and surface precipitation products were also analyzed to discuss howthe different physical properties lead to the different precipitation of summer precipitation clouds over studying regions. The results showed that:( 1) As to the macrophysical properties of clouds,the main precipitation clouds of the Qinghai-Xizang Plateau were Cu and Ci,lowlevel clouds accounted for the largest proportion,it were Ns and Ci in Sichuan Basin and transition region. Compared with Basin,the clouds base was higher and top was lower in Plateau,it could rain while convection will not deep enough. In three regions,single layer cloud was easier to rain than multilayer one.( 2) As for the microphysical properties of clouds,the main precipitation clouds of the Qinghai-Xizang Plateau was ice cloud,mixed cloud was second,the least was liquid water cloud,mixed cloud accounted for the largest proportion in Sichuan Basin. The clouds were mostly at the beginning of lifetimes in statistics,although the differences were not obvious,the effective radius and distribution width parameter of cloud ice particles over the Qinghai-Xizang Plateau were bigger and wider than those in the other two regions. Their number concentration were similarly,that could quicken the cold cloud processes. It was slower to developed ice cloud processes in Sichuan Basin than that in the QinghaiXizang Plateau.