Identifying Global Monsoon Troughs and Global Atmospheric Centers of Action on a Pentad Scale  

作　　者：QIAN Wei-Hong TANG Shuai-Qi 

机构地区：[1]Department of Atmospheric Science, Peking University, Beijing 100871, China

出　　处：《Atmospheric and Oceanic Science Letters》2010年第1期1-6,共6页大气和海洋科学快报（英文版）

基　　金：supported jointly by the National Natural Science Foundation of China (40975039);the National Basic Research Program of China (2006CB403602 and 2009BAC51B04)

摘　　要：Using two datasets of global pentad grid precipitation and global 850 hPa geopotential height during 1979-2007,this study identified global monsoon troughs and global atmospheric centers of action (ACAs) on a pentad scale.The global monsoon troughs consist of planetary-scale monsoon troughs and peninsula-scale monsoon troughs.Forced by seasonal variations in solar radiation,the inter-tropical convergence zones (ITCZs) represent the planetary-scale monsoon troughs,which are active and shift over the tropical North Pacific,the tropical North Atlantic,and the tropical South Indian oceans.The peninsula-scale monsoon troughs are originated from regional land-sea topography and varied with contrasts in seasonal land-sea surface temperatures and precipitation.During the boreal summer,five peninsula-scale troughs and one planetary-scale trough are distributed in the Asia-Northwest Pacific (NWP) region.In total,22 troughs,nine monsoon troughs,and 19 ACAs in the lower troposphere were identified.Relevant ACAs may be useful in constructing regional monsoon and circulation indices.Using two datasets of global pentad grid precipitation and global 850 hPa geopotential height during 1979-2007, this study identified global monsoon troughs and global atmospheric centers of action （ACAs） on a pentad scale. The global monsoon troughs consist of planetary-scale monsoon troughs and peninsula-scale monsoon troughs. Forced by seasonal variations in solar radiation, the inter-tropical convergence zones （ITCZs） represent the planetary-scale monsoon troughs, which are active and shift over the tropical North Pacific, the tropical North Atlantic, and the tropical South Indian oceans. The peninsula-scale monsoon troughs are originated from regional land-sea topography and varied with contrasts in seasonal land-sea surface temperatures and precipitation. During the boreal summer, five peninsula-scale troughs and one planetary-scale trough are distributed in the Asia-Northwest Pacific （NWP） region. In total, 22 troughs, nine monsoon troughs, and 19 ACAs in the lower troposphere were identified. Relevant ACAs may be useful in constructing regional monsoon and circulation indices.

关 键 词：monsoon trough planetary scale peninsula scale atmospheric centers of action pentad scale 

分 类 号：P434[天文地球—大气科学及气象学] P432