The advance and distribution of the belts of rainfall and of heavy rainfall in China are closely related to sudden seasonal changes in the general circulation over East Asia, but the latter, to a great extent, may be the result of thermal and dynamic forcing by the Qinghai-Xizang (Tibet) Plateau. Observational evidence indicates that many synoptic systems have their origin in the planetary boundary layer over the plateau and its surroundings. They act as producers not only of severe weather events over the plateau itself, but also of very important rain-bearing synoptic systems over eastern, southern, and even northern China that have been steered out of the plateau. The present study is based on excessively heavy rainfalls that have occurred during the past 50 years (1931–80), and which caused serious, damaging floods in much of China. The presence and influence of Tibetan weather systems could be found in most of these heavy rainfall events. The low-level vortices originating in the plateau play a very significant role in producing the heavy rains.
1 Prof. Tao Shi-yen is now Deputy Director of the Institute of Atmospheric Physics, Academia Sinica; Standing Executive of the Chinese Meteorological Society; member of the Working Group of Atmospheric Science under the Committee of Science and Technology; Vice-President of the Chinese Geographical Society; Deputy to the National People's Political Consulting Congress; and member of the Commission for Atmospheric Sciences (CAS) of WMO.
2 Prof. Ding Yi-hui is Deputy Director of the Laboratory on Typhoon and Severe Convective Weather, Institute of Atmospheric Physics, Academia Sinica. He is now a visiting scientist in the Department of Atmospheric Science, Colorado State University, Ft. Collins, Colo. 80523. (Comments by E. R. Reiter.)