The East Asia-Western North Pacific Boreal Summer Intraseasonal Oscillation Simulated in GAMIL 1.1.1  

作　　者：杨静 Bin WANG 王斌 李立娟 

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 [2]State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875 [3]Department of Meteorology and International Pacific Research Center,University of Hawaii at Manoa, Honolulu, HI 96822, USA

出　　处：《Advances in Atmospheric Sciences》2009年第3期480-492,共13页大气科学进展（英文版）

基　　金：supported by the Innovative Research Group Funds (Grant No. 408210921);the CAS International Partnership Project;the 973 Project(Grant Nos. 2005CB321703 and 2006CB403602);fund from State Key Laboratory of Earth Surface Processes and Resource Ecology (No. 070205) in Beijing Normal University

摘　　要：We evaluate the performance of GAMILI.1.1 in a 27-year forced simulation of the summer intraseasonal oscillation （ISO） over East Asia （EA）-western North Pacific （WNP）. The assessment is based on two mea- sures： climatological ISO （CISO） and transient ISO （TISO）. CISO is the ISO component that is phase-locked to the annual cycle and describes seasonal march. TISO is the ISO component that varies year by year. The model reasonably captures many observed features of the ISO, including the stepwise northward advance of the rain belt of CISO, the dominant periodicities of TISO in both the South China Sea-Philippine Sea （SCS-PS） and the Yangtze River Basin （YRB）, the northward propagation of 30-50-day TISO and the westward propagation of the 12-25-day TISO mode over the SCS-PS, and the zonal propagating features of three major TISO modes over the YRB. However, the model has notable deficiencies. These include the early onset of the South China Sea monsoon associated with CISO, too fast northward propagation of CISO from 20°N to 40°N and the absence of the CISO signal south of 10°N, the deficient eastward propagation of the 30-50-day TISO mode and the absence of a southward propagation in the YRB TISO modes. The authors found that the deficiencies in the ISO simulation are closely related to the model＇s biases in the mean states, suggesting that the improvement of the model mean state is crucial for realistic simulation of the intraseasonal variation.We evaluate the performance of GAMILI.1.1 in a 27-year forced simulation of the summer intraseasonal oscillation （ISO） over East Asia （EA）-western North Pacific （WNP）. The assessment is based on two mea- sures： climatological ISO （CISO） and transient ISO （TISO）. CISO is the ISO component that is phase-locked to the annual cycle and describes seasonal march. TISO is the ISO component that varies year by year. The model reasonably captures many observed features of the ISO, including the stepwise northward advance of the rain belt of CISO, the dominant periodicities of TISO in both the South China Sea-Philippine Sea （SCS-PS） and the Yangtze River Basin （YRB）, the northward propagation of 30-50-day TISO and the westward propagation of the 12-25-day TISO mode over the SCS-PS, and the zonal propagating features of three major TISO modes over the YRB. However, the model has notable deficiencies. These include the early onset of the South China Sea monsoon associated with CISO, too fast northward propagation of CISO from 20°N to 40°N and the absence of the CISO signal south of 10°N, the deficient eastward propagation of the 30-50-day TISO mode and the absence of a southward propagation in the YRB TISO modes. The authors found that the deficiencies in the ISO simulation are closely related to the model＇s biases in the mean states, suggesting that the improvement of the model mean state is crucial for realistic simulation of the intraseasonal variation.

关 键 词：intraseasonal oscillation （ISO） East Asia-Western North Pacific （EA-WNP） 

分 类 号：P462.4[天文地球—大气科学及气象学]