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The seasonal variation of Tibetan Convective Systems: Satellite observation
Author(s) -
Hu Liang,
Deng Difei,
Gao Shouting,
Xu Xiangde
Publication year - 2016
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2015jd024390
Subject(s) - plateau (mathematics) , precipitation , climatology , international satellite cloud climatology project , environmental science , satellite , seasonality , convection , atmospheric sciences , geography , cloud cover , geology , meteorology , cloud computing , mathematical analysis , statistics , mathematics , engineering , aerospace engineering , computer science , operating system
Based on International Satellite Cloud Climatology Project (ISCCP) Convection Tracking Database (CTD) data set, a new definition for the Tibetan Convective System (TCS) is introduced, in which the effects of cirrus and cirrostratus are excluded from the TCS over this region. 2032 TCSs are selected to study their seasonal variations in initiation, frequency, spatial distribution, life cycle, cloud physics, precipitation, and dynamic and thermodynamic characteristics. It is found that the number of TCSs varies seasonally, with the maximum in July and minimum in December. The 10%, 8%, 9%, and 73% TCSs are originated from Tibetan shear, vortex, low, and the rest, respectively. TCSs play an important role in the precipitation of the Tibetan Plateau and its adjacent regions. Even in winter, the rainfall of TCS contributes up to 70% of the total precipitation over the central‐eastern Tibetan Plateau and 30%–70% over Sichuan basin and upper‐middle segment of Yangtze River basin. The seasonal changes of TCSs' cloud properties from ISCCP indicate that the strongest TCSs happen in summer and the weakest in winter, which are consistent with the seasonal variation of TCSs' rainfall observed by TRMM. Besides, TCSs show an asymmetric dynamic and thermodynamic distribution, especially in summer.