南亚海陆热力差异及其对热带季风区环流的影响  

LAND-SEA THERMAL CONTRAST OVER SOUTH ASIA AND ITS INFLUENCES ON TROPICAL MONSOON CIRCULATION

作　　者：王同美[1,2,3] 吴国雄[1] 

机构地区：[1]中国科学院大气物理研究所,LASG,北京100029 [2]中山大学季风与环境研究中心,大气科学系,广东广州510275 [3]中国科学院研究生院,北京100039

出　　处：《热带气象学报》2008年第1期37-43,共7页Journal of Tropical Meteorology

基　　金：Key National Fundamental Research Foundation (2006CB403607);Natural ScienceFoundation of China (40475027; 40221503)

摘　　要：利用NCEP/NCAR再分析资料,分析了亚洲热带季风区海陆分布所造成的热力差异,以及空间非均匀加热对热带季风区环流特别是初夏过渡季节环流的影响。在大尺度环流背景下,次大陆地形对亚洲热带地区环流的影响主要表现在对低层环流的热力作用,其中感热加热对冬、春季环流的影响明显,对秋季环流的作用相对较小。中南半岛和印度半岛之间的热力差异及其对环流的影响受到青藏高原的调配作用。在初夏过渡季节,高原热力强迫作用于低纬低层环流,使低纬约90°E以东出现南风加强、以西出现北风加强,从而增强了中南半岛上空的潜热加热,减弱了其低层的感热加热,印度半岛地区还加强了低层的感热加热。多尺度、各种性质的加热共同作用于低纬大气,形成了亚洲热带地区独有的环流特征。Based on the NCEP/NCAR reanalysis data, the thermodynamic features and the effect of spatially nonuniform heating on the circulation of the tropical monsoon area in South Asia due to the land-sea distribution are analyzed. The influences of the subcontinent topography on the Asian tropical circulation are mostly characterized by its thermodynamic effects on low-level circulation, of which the strongest is observed in winter and spring but the relatively weak in summer, followed by the weakest in autumn. The thermodynamic difference between the Indochina Peninsula and Indian Peninsula and its influence on the circulation are regulated by the Tibetan Plateau. During the transitional period from spring to early summer, the Tibetan Plateau thermal forcing generates a large-scale cyclonic circulation in low latitudes in the lower troposphere. As a result, the southerlies/northerlies are increased to the east / west of the Bay of Bengal, Therefore latent heating of the atmosphere is strengthened and the surface sensible heating over the Indochina Peninsula is weakened. On the other hand the surface sensible heating over the Indian Peninsula is increased. It is shown that heating with various scales and different kinds can affect the tropical atmosphere in different ways, which lead to the unique characteristics of the tropical Asian circulation.

关 键 词：海陆分布 热力差异 热带季风区 

分 类 号：P461.2[天文地球—大气科学及气象学]