【摘要】 本文采用一个有限区域七层原始方程诊断模式,利用己知的多年1月平均高度场,对方程进行迭代求解,得到水平和垂直运动场。通过对结果的分析,发现用此方法得到的诊断风场比地转风场更接近实际,特别是急流区。另外发现高原地区冬季的平均流场具有以下几个特征:1、从高原对气流的影响,可以把对流层分为三种不同情况,850mb以下为摩擦影响层;700—300mb为绕流影响层,400mb以上高原对气流除了绕流分支作用外,爬坡作用明显增加;可到了125mb这种机械障碍物作用己明显减少。2、高原地区的垂直运动与降水量有较好的对应关系,尤其是高原南坡的上升运动有一大降水带与之对应,最大值可达5×10^-3mb/秒。3、从经向垂直环流图的分析发现,紧贴高原南坡出现一个局地哈德莱环流,它与高原南部的哈德莱环流是分开的两支。它进一步证实了高原地区确实存在一个独立的季风系统。更多还原

【Abstract】 The Winter mean circulation in East Asia is investigated by using a seven-layer primitive equation diagnostic model with a horizontal grid size of 2.5°×2.5°.The calculated results show that the calculated diagnostic wind fields are more similar to climatology than the geostrophic wind fields, especially, in the jet stream area. The effects of the Plateau on flows can be classified into three cases: 1.The layer under 850mb is a fric-tional layer; 2.The layer from 700mb to 300mb is a flow-around layer. In this layer the winds tend to flow around rather than to cross over the Plateau, above 400mb the components of the crossing over apparently increase; 3.At 125mb the barrier effect of the Plateau on flow decreases. The calculated vertical motion is found to be consistent with precipitation. A local direct Hadley cell is Present in the Plateau area.更多还原