Relationship between the Monthly Variation of the East Asia Westerly Jet and the Huaihe River Valley Rainfall Anomaly in Summer
Relationship between the Monthly Variation of the East Asia Westerly Jet and the Huaihe River Valley Rainfall Anomaly in Summer
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发表时间：
2011
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通讯作者：
Zhang Qingyun
中科院分区：
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作者：
Zhang Qingyun
利用NCEP/NCAR再分析资料和1979 - 2008年中国160个测站的月降水资料，逐月分析了东亚西风急流与淮河流域夏季降水的关系。6月东亚西风带偏北，亚洲中高纬环流形势呈两脊一槽，冷空气活动弱，HRV受异常南风控制，有利于该地区降水偏多，降水偏少年份则相反，HRV偏多年份，东亚西风带向南移动到其气候位置，南亚高压偏东，西太平洋副热带高压偏西偏强，导致7、8月HRV降水偏多，反之亦然。东亚西风急流强度和位置的变化受亚洲中高纬环流的影响较大，而在7、8月份，东亚西风急流强度和位置受热带、副热带环流的影响较大。
Relationship between the East Asia Westerly Jet(EAWJ) and the Huaihe River Valley(HRV) summer rainfall was investigated month by month,using the NCEP/NCAR reanalysis data and the monthly rainfall data at 160 stations in China from 1979 to 2008.It was found that the HRV summer rainfall is closely related to the monthly variation of the EAWJ.In the years with more rainfall over the HRV,the EAWJ is located northward than normal and the circulation pattern exhibits two ridges and one trough in mid-high latitudes of Asia in June.The cold air activities are weak and the HRV is controlled by anomalous southerlies,which favors more precipitation there.The situation is almost opposite in the years with less rainfall.In the years with more rainfall over the HRV,the EAWJ moves southward to its climatic location,the South Asia high is located eastward than normal,and the western Pacific subtropical high is stronger and is located westward than normal,resulting in more precipitation in the HRV during July and August,and vice versa.The analyses indicate that in June,the change in the intensity and location of the EAWJ is more inf-luenced by the mid-high latitude circulations of Asia.However,in July and August,the intensity and location of the EAWJ is more affected by the variation of the tropical and subtropical circulations.