Reason Analysis of the Influence of Qinghai-Xizang Plateau Uplifting on Arid Climate Forming in Northwest China (I): Influence on General Circulation of Atmosphere

To understand the forming causes of the Northwest China(NW China) drought area and to study the influence of the QinghaiXizang Plateau uplifting on the general circulation NW China. In this paper, the general circulation differences over the Northern Hemisphere, especially the China, among before, during and after the QinghaiXizang Plateau uplifting is simulated by 3 numerical simulation experiments of NCAR CCM3. The results show that the uplifting of the QinghaiXizang Plateau can clearly effect the general circulation of the Northern Hemisphere especially the NW China, such as the sea level pressure, 500 hPa and 100 hPa levels. Before the QinghaiXizang Plateau is uplifted or during it is uplifted up to the critical height, about 2 km ASL, the sea level pressure, 500 hPa and 100 hPa level heights are all lower than they are now all over the most part of the Northern Hemisphere. And the changes are all consistent with each other in every season. It can clearly effect the general circulation of the Northern Hemisphere, especially the NW China; when the QinghaiXizang Plateau is uplifted up to the critical height. This will make the climate condition to be clearly changed.