青藏高原地表热通量变化及其对初夏东亚大气环流的影响

应用NCEP地面热通量资料, 研究了青藏高原地面感热、潜热的气候状况及其与初夏东亚大气环流之间的关系。发现高原地面热通量的异常将影响高原地区上空的垂直运动与辐散辐合运动, 从而引起东亚地区高度场及风场的异常。同时, 青藏高原地区地面热通量与后期东亚地区的环流变化也有密切关系, 这种关系可为预测东亚地区初夏环流异常提供有意义的指标。

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 ove r Ti betan Plateau and its relation with the East Asia Circulation in early summer ar e 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 Pla teau enhances the High system over Tibetan area and its adjacent regions. It als o enhances the westerly jet stream in the north side of the Plateau. The abnorma l 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 Pla teau in the preceding seasons has some significant linkage with the succeeding h eight and zonal wind fields in early summer. These relations can be used as pred ictors for the circulation anomalies in early summer of East Asia