Possible Causes of the Interdecadal Transition of the Somali Jet Around the Late 1990s  

作　　者：肖子牛 石文静 杨萍 

机构地区：[1]Department of Atmospheric Science, Nanjing University of Information Science & Technology [2]State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics, Chinese Academy of Sciences [3]Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin-Madison,Madison, WI 53706, USA [4]China Meteorological Administration Training Center

出　　处：《Journal of Meteorological Research》2015年第2期214-227,共14页气象学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(41175051 and 41375069);National Basic Research and Development(973)Program of China(2012CB957804);Postgraduate Science and Technology Innovation Project of Jiangsu Province(CXZZ13-0517);the China Scholarship Council(CSC)

摘　　要：This observational study demonstrates that the Somali jet（SMJ） experienced a notable interdecadal transition in not only its lower-level parts（〈 850 hP a） but also its higher-level parts（850-600 h Pa） in the late 1990 s. The results also show that the jet at higher level is more significantly related to East Asian monsoon rainfall than that at lower level. Thus, a new whole-layer SMJ（WSMJ） index which includes variations of the higher-level jet is defined based on the average meridional wind speed at five levels（1000-600 h Pa）. The interdecadal transition of the SMJ can be mainly attributed to the meridional thermal contrast anomalies near the equator which are associated with the three-pole pattern of the southern Indian Ocean.This observational study demonstrates that the Somali jet（SMJ） experienced a notable interdecadal transition in not only its lower-level parts（〈 850 hP a） but also its higher-level parts（850-600 h Pa） in the late 1990 s. The results also show that the jet at higher level is more significantly related to East Asian monsoon rainfall than that at lower level. Thus, a new whole-layer SMJ（WSMJ） index which includes variations of the higher-level jet is defined based on the average meridional wind speed at five levels（1000-600 h Pa）. The interdecadal transition of the SMJ can be mainly attributed to the meridional thermal contrast anomalies near the equator which are associated with the three-pole pattern of the southern Indian Ocean.

关 键 词：interdecadal transition Somali jet index Asian summer monsoon southern Indian Ocean sea surface temperature 

分 类 号：P442[天文地球—大气科学及气象学]