冬季青藏高原对东移大槽动力影响的研究 （Ⅱ）理想初始场、地形场的构造和数值试验方案的设计

STUDIES OF DYNAMIC INFLUENCE OF QINGHAI-XIZANG PLATEAU ON THE EASTWARD MOVING TROUGH IN WINTER PART Ⅱ. THE CONSTRUCTIONS OF THE IDEALIZED INITIAL FIELDS AND OROGRAPHIC FIELD AND THE DESIGN OF SIMULATION EXPERIM

为了以数值试验手段定量地再现青藏高原地形对冬季东移大槽的影响，也同时讨论冬季亚洲不同高空环流形势下地形对东移槽影响的差别，本文使用我所６层有限区域格点模式，首先根据该模式对初始场的需要，也源于冬季亚洲地区高空流型的特点，构造了以基本斜压西风气流加高空西风急流，并在其上迭加正弦波槽扰动为主要特征的环境流场等的理想初始场及理想地形场。然后，根据不同流场成员和地形的组合，设计了１３个数值模拟试验。接着，利用整层无辐散初始化方案，固定侧边界条件，对各试验积分４—５天，最后分析各试验中东移槽的行为。本研究第三部分的模拟试验结果的分析表明〔１９〕，模式计算稳定，模拟结果合理，说明文中理想场的构造是协调的、合理的，也比较接近实际。侧边界条件及初始场的预处理也大体是合适的。

In order to reproduce quantitatively the influence of Qinghai-Xizang Plateau on the eastward moving trough (EMT) in winter and to, also, discuss the differences among the terrain impacts under the different circulation, in this paper, the second part of the series papers, a limited area grid point model with 6 levels in the vertical and resolution of 1.875°×1.875°Lon./Lat. in the horizontal is used. According to the demand for the model initial fields and the characters of the Asian upper circulation observed in winter, the idealized initial fields including environmental flow field, characterized by superposed a sine wave shaped trough turbulence on the basic baroclinic westerly flow and westerly Jet, and idealized orographic field are firstly constructed, then a set of 13 experiments, which consist of different member of flow field and orography, are designed. After that, initialization scheme of non-divergence on all levels and fixed lateral boundary condition are utilized to integerate each experiment for 4-5 days. Finally, the behaviour of EMT in each experiment are analysed. The results analysis in the third part of the series papers show that the model is computed stably and the simulated results are reasonable, namely, the idealized initial fields are constructed harmoniously and reasonably, and also argeed quite well with the actual situation. The treatments of lateral boundary condition and initial fields are also appropriate.