冬季青藏高原对其周围地区流场影响的模拟实验
AN ANNULUS EXPERIMENTAL SIMULATION OF THE INFLUENCE OF THE CHINGHAI-TIBETAN PLATEAU ON THE WIND FIELD OVER ITS ADJACENT REGIONS IN WINTER
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摘要: 本文应用转盘模拟实验的方法,模拟了冬季青藏高原及其邻近地区流场的状况,通过实验看到: 冬季东亚大槽的形成和强弱,不仅与海陆分布及高原的动力作用有关,而且高原的热力作用也很重要;高原及其邻近地区上空的大气作为冷源,对其南北两侧的垂直环流的形成也有直接关系。此外,我们看到冷高原可使南支气流产生小槽东移的现象。在实验中,我们分别用中性高原模型,冷性高原模型和部分加热高原模型作了对比实验,揭示了高原的一系列动力作用和热力作用。Abstract: In this paper, the winter circulation over Tibetan Plateau and its adjacent regions is simulated in a rotating annulus. The main results are as follows: In winter, the formation and the intensity of the major trough over Eastern-Asia is not only related to the Continent-Ocean distribution and the dynamical role of the Plateau, but also to the thermodynamic effect of the Plateau which is also very important.The atmosphere over the plateau and its adjacent regions is a cold source in winter, The meridional vertical circulation to the south and north of the plateau is directly related to the cooling effect over the plateau.Besides, we find that a cooling modle plateau may give rise to minor troughs moving eastward on the southern branch current to the south of the plateau.By comparing the experimental results of a nonheating and noncooling model plateau,a cooling model plateau and a partly heating model plateau, some dynamic and the thermodynamic roles of the plateau are revealed.