RECENT PROGRESS IN THE STUDY ON THE IMPACTS OF TIBETAN PLATEAU ON ASIAN SUMMER CLIMATE

The recent progresses in the study of the impacts of Tibetan Plateau on Asian summer climate in the last decade are reported. By analyzing the evolution of the interface between westerly to the north and easterly to the south (WEB), it is shown that due to the strong heating over Tibetan Plateau in spring, the overturning in the prevailing wind direction from easterly in winter to westerly in summer occurs firstly over the eastern Bay of Bengal (BOB), accompanied with vigorous convective precipitation to its east. The area between East BOB and western Indochina Peninsula thus becomes the area of the earliest Asian monsoon onset, which is referred as BOB monsoon in short. It is shown that the summertime circulations friggered by the thermal forcing of Iran Plateau and Tibetan Plateau are embedded in phase with the continental-scale circulat ion forced by the diabatic heating over the Eurasian Continent. As a result the East Asian summer monsoon is intensified and the droaught climate over the west ern and central Asian areas is enhanced. These together with the perturbations friggered by the Plateau and associated heating exert important influences on the climate patterns over Asia. Furthermore the charact eristics of the Tibetan mode of the summert ime South Asian High are compared with those of Iran mode. Results demonstrate that corresponding to each of the bimodality of the South Asian High, the rainfall anomaly distributions over Asia possess different pat terns.