区域气候模式对地形影响东亚大气环流季节变化的数值模拟研究  

Numerical simulation of the influence of East Asia orography on the atmospheric circulation by Regional Climate Model

作　　者：闵莉[1] 张志刚 刘文菁[3] 陈宁[3] 吴云荣 

机构地区：[1]南京大学大气科学系,南京210093 [2]盐城市气象局,江苏盐城224005 [3]江苏省气象局,南京210008

出　　处：《气象科学》2008年第2期155-162,共8页Journal of the Meteorological Sciences

基　　金：省科技厅社会发展项目(BS2006088)

摘　　要：利用ICTP新推出的高分辨率第三代区域气候模式RegCM3,进行了有、无地形高度两个数值试验。通过分析两个试验模拟的环流场和降水场等的差异特征来研究东亚地区地形影响大气环流的季节变化特征。结果表明,东亚地形对大气环流的影响存在较明显的季节变化。冬季/夏季高层流场差异场的特点是以高原为中心成反气旋/气旋性环流形势,这种结构特征对西风急流的季节性北进南退起主导作用。位势高度差异场呈北高南低的分布形势,大致以30°N为分界线,冬季/夏季呈"北弱南强","陆地低海洋高"/"北强南弱"、"陆地高海洋低"的分布特征,这种配置对西风急流越过高原后强度的增强减弱关系密切。此外,地形对大气的辐射加热作用的季节性变化以及海陆热力差异的季节性振荡也说明地形不仅能通过动力和热力作用来直接影响高低层的环流系统,也可能通过调节海陆热力差异来间接影响季风环流。A new regional climate model developed by ICTP--RegCM3 is used to simulate the influences of orography on the atmospheric circulation in different seasons. Two experiments are presented：one is with full orography and the other without orography. The difference between the two experiments of circling fields and precipitations is analysed. Results show that such influences are seasonally dependant. The pattern in winter is featured as anticyclonic flow and in summer as cyclonic flow. This structure is associated with the west jet＇s seasonal motion. For the height difference, the pattern is characterized by the north and south seesaws along 30 N, with high to the north and low to the south in summer and high to the south and low to the north in winter. This seasonal variation of the height difference may be connected with the annual intensity of the EAWJ. Orograph and the lower level circumfluence fields phy may have indirect effect on circling y may affect the upper level circumfluence fields by heating effect by both heating effect and dynamical forcing. In addition, orografields by changing the land-sea thermal difference.

关 键 词：地形 环流场 季节变化 

分 类 号：P435[天文地球—大气科学及气象学]