THE VARIATION OF SURFACE HEAT FLUX OVER TIBET PLATEAU AND ITS INFLUENCES ON THE EAST ASIA CIRCULATION IN EARLY SUMMER

Using the NCEP reanalysis data, the climatology of the surface heat flux over Tibetan Plateau and its relation with the East Asia Circulation in early summer are studied. It is found that: the surface heat flux over Tibet shows strong annual cycle; both the latent heat flux over Tibet enhances the upward vertical motion in the middle troposphere over Tibetan area; the heat flux over the Tibetan Plateau enhances the High system over Tibetan area and its adjacent regions. It also enhances the westerly jet stream in the north side of the Plateau. The abnormal surface heat over Tibet will speed up the seasonal transition process in the East Asia from winter to summer. The surface heat condition over Tibetan Plateau in the preceding seasons has some significant linkage with the succeeding height and zonal wind fields in early summer. These relations can be used as predictors for the circulation anomalies in early summer of East Asia