The Formation of Precipitation Anomaly Patterns during the Developing and Decaying Phases of ENSO  

作　　者：HU Kai-Ming HUANG Gang 

机构地区：[1]State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China

出　　处：《Atmospheric and Oceanic Science Letters》2010年第1期25-30,共6页大气和海洋科学快报（英文版）

基　　金：supported by the National Basic Research Program of China (2006CB400503);the National Natural Science Foundation of China (40890155,40775051,and U0733002);Project KZCX2-YW-220 of the Chinese Academy of Sciences

摘　　要：This study proposes a new explanation for the formation of precipitation anomaly patterns in the boreal summer during the E1 Nifio-Southem Oscillation （ENSO） developing and decaying phases. During the boreal sum- mer June-July-August （JJA） （0） of the E1 Nino （La Nina） developing phase, the upper level （300-100 hPa） positive potential temperature anomalies resemble a Ma- tsuno-Gill-type response to central Pacific heating （cool- ing）, and the lower level （1000-850 hPa） potential tem- perature anomalies are consistent with local SST anoma- lies. During the boreal summer JJA（1） of the E1 Nifio （La Nifia） decaying phase, the upper level potential tempera- ture warms over the entire tropical zone and resembles a Matsuno-Gill-type response to Indian Ocean heating （cooling）, and the lower level potential temperature anomalies follow local SST anomalies. The vertical heterogeneity of potential temperature anomalies influences the atmospheric stability, which in turn influences the precipitation anomaly pattern. The results of numerical experiments confirm our observations.This study proposes a new explanation for the formation of precipitation anomaly patterns in the boreal summer during the El Nio-Southern Oscillation (ENSO) developing and decaying phases.During the boreal summer June-July-August (JJA) (0) of the El Nio (La Nia) developing phase,the upper level (300-100 hPa) positive potential temperature anomalies resemble a Matsuno-Gill-type response to central Pacific heating (cooling),and the lower level (1000-850 hPa) potential temperature anomalies are consistent with local SST anomalies.During the boreal summer JJA(1) of the El Nio (La Nia) decaying phase,the upper level potential temperature warms over the entire tropical zone and resembles a Matsuno-Gill-type response to Indian Ocean heating (cooling),and the lower level potential temperature anomalies follow local SST anomalies.The vertical heterogeneity of potential temperature anomalies influences the atmospheric stability,which in turn influences the precipitation anomaly pattern.The results of numerical experiments confirm our observations.

关 键 词：precipitation pattern ENSO AGCM 

分 类 号：P426.615[天文地球—大气科学及气象学] P732