NUMERICAL STUDY ON THE DYNAMIC AND THERMODYNAMIC EFFECTS OF THE QINGHAI-XIZANG PLATEAU ON THE SEASONAL TRANSITION IN THE EARLY SUMMER IN EAST ASIA

作     者：郑庆林 吴军 

作者机构：Chinese Academy of Meteorological SciencesBeijing 100081 

出 版 物：《Acta meteorologica Sinica》 (气象学报(英文版))

年 卷 期：1995年第9卷第1期

页      面：35-47页

学科分类：07[理学] 0707[理学-海洋科学] 070601[理学-气象学] 0815[工学-水利工程] 0706[理学-大气科学] 0816[工学-测绘科学与技术] 0824[工学-船舶与海洋工程] 0825[工学-航空宇航科学与技术] 

主　　题：seasonal transition Qinghai-Xizang Plateau dynamic effect thermodynamic effect 

摘      要：By employing a five-layer seasonal numerical weather prediction model and utilizing the National Meteorological Center (NMC) objective analysis data on May 10,1991 as the initial field,three numerical experiments——diabatic with orography,adiabatic with orography and adiabatic without orography——have been carried out to investigate the dy- namic and thermodynamic effects of the Qinghai-Xizang Plateau (hereafter the Plateau) on the seasonal transition in the early summer in East *** results show that the typical seasonal transition features such as the northward shift of the subtropical westerly jet stream,the adjustment of the long-wave in middle and high latitudes and the changes of the circulation in the lower troposphere can be well simulated,if the dynamic and thermodynamic effects of the Plateau are both considered in the model as in the experiment adiabatic with *** other two experiments,it is failed to simulate out the seasonal transition features. The results also show that the thermodynamic effect of the Plateau acts on the atmosphere as a gradually enhanced heating source in the early summer,which makes the air temperature in 500 hPa over the Plateau increase by nearly 10℃ in a month and accelerates the northward shift of the subtropical westerly jet stream about seven latitudes more north- ward in twenty days and helps the shifted jet maintain at the northern periphery of the *** is also helpful to the formation and maintenance of the Lake Balchas trough and the northward and westward extension of the Pacific subtropical *** the other hand,the dynamic effect of the Plateau weakens the northward shift of the subtropical westerly jet stream and barricades the westward extension of the Pacific subtropical *** only the dynamic effect of the Plateau is considered in the model without consideration of the thermodynamic effect of the Plateau,not only the shifted jet withdraws southward but also the simulated Lake Balchas trough is 10