Zonal thermal difference between East-Asia and West Pacific and its relationship with East Asian subtropical southerly onset

摘要

Based on analysis of the temperature latitudinal deviation on middle troposphere on a climate basis, its seasonal cycle suggests that due to the Tibetan Plateau heating in spring, seasonal transition of the thermal difference between East Asia continent and West Pacific first takes place on the subtropical region, accompanied by the prevailing wind turning from northerly in winter to southerly in summer on low troposphere The precipitation takes place at the same time. This maybe indicates the East Asian subtropical summer monsoon onset. Consequently, it is advanced that the seasonal cycle formed by the zonal thermal contrast between Asian continent and western Pacific may be an independent driving force of East Asian subtropical monsoon.