亚洲和南半球大气冷(热)源对亚洲冬季风影响的数值试验

利用NCAR CAM3.1模式及NCEP/NCAR(version 1)再分析资料计算了几种现实大气热源分布情况,讨论了亚洲各地区和南半球上空冬季1月大气冷(热)源对东亚冬季风环流系统和印度冬季风环流系统形成的影响.结果表明:(1)冬季1月东亚地区和澳大利亚上空大气冷(热)源与东亚冬季风环流关系密切,南半球澳大利亚附近的非绝热加热可以激发出澳大利亚北部的热低压系统,东亚大陆东部的大气冷源可以使东亚大陆低空出现冷高压,基本上模拟出东亚季风系统冬季主要环流成员;(2)亚洲地区西部及其对应的南半球印度洋非绝热加热与印度冬季风环流关系密切,同样对东亚冬季风也有一定的影响,特别是亚洲大陆西部副热带地区的非绝热加热可以加强冬季南海的越赤道气流并能调整阿留申低压的位置.

Numerical Analysis for Impacts of Atmospheric Heat Source Distribution over Asia and Southern Hemisphere on Asian Winter Monsoon

The impact of atmospheric cold(heat)source distribution over Asia and the Southern Hemi-sphere in January on the East Asian winter monsoon and Indian winter monsoon is simulated with the NCAR CAM3.1 model based on the distribufion of heat source calculated from NCEP/NCAR (version 1)reanalysis datasets.The following conclusions are arrived at:Firstly,in January,the cold(heat)sources over East Asia and Australia are close related with the East Asian winter monsoon,the diabatic heating over Australia and its peripheral areas can induce the heat low system over the north of Austral-ia:the atmospheric cold source over the east of the East Asian continent lcads to the occurrence of cold high in the low troposphere over the region,the major circulation members of the East Asian winter monsoon system are fairly well simulated. Secondly, the diabatic heating over the west part of Asian re-gion and the Indian Ocean south of the equator is associated with the Indian winter monsoon very well:likewise.there is also a relationship between this heating and the East Asian winter monsoon,in parti-cular.the diabatic heating over the subtropical regions of western Asia can strengthen the winter cross-equatorial flow over the South China Sea and alter the position of the Aleutian low.