Publication Date:
2016-05-13
Description:
Based on International Satellite Cloud Climatology Project (ISCCP) Convection Tracking Database (CTD) dataset, 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, dynamic and thermodynamic characteristics. It is found that the number of TCSs varies seasonally, with the maximum in July and minimum in December. 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.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
