Objective identification research on cold vortex and mid-summer rainy periods in Northeast China

作     者：龚志强 封泰晨 房一禾 Gong Zhi-Qiang;Feng Tai-Chen;Fang Yi-He

作者机构：Laboratory for Climate Studies and Climate Monitoring and DiagnoseNational Climate Center China Meteorological Administration Atmosphere and Science College Lanzhou University Regional Climate Center of Shenyang 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2015年第24卷第4期

页      面：571-580页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.41205040 and 41375078) the State Key Development Program for Basic Research,China(Grant No.2012CB955203) the Special Scientific Research Project for Public Interest(Grant No.GYHY201306021) 

主　　题：Northeast China cold vortex rainy period mid-summer rain period objective identification method 

摘      要：Considering the differences between the Northeast China Cold Vortex （CV） and the Mid-Summer （MS） rainy period and their corresponding atmospheric circulations are comprehensively analyzed, and the objective identification methods of defining the annual beginning and ending dates of Northeast China CV and MS rainy periods are developed respectively. The annual beginning date of the CV （MS） rainy period is as follows. In a period from April to August, if daily regional mean precipitation ryi is larger than yearly regional mean precipitation R （or 2R） on a certain day, the station precipitation rs is larger than the station yearly mean precipitation （r/ （or 2（r）） in at least 50% of stations in Northeast China, and this condition is satisfied in the following 2 （7） days, then this date is defined as the beginning date of the CV （MS） rainy period. While the definition of the ending date of the MS rainy period shows the opposite process to its beginning date. With this objective identification method, the multi-year average （1981-2010） beginning date of the CV rainy period is May 3, the beginning date of the MS rainy period is June 27, the ending day of the CV rainy period is defined as the day before the beginning date of the MS rainy period, and the ending date of the MS rainy period is August 29. Meanwhile, corresponding anomaly analysis at a 500-hPa geopotential height, 850-hPa wind, Omega and relative humidity fields all show that the definitions of the average beginning and ending dates of the CV and MS rainy periods have a certain circulation meaning. Furthermore, the daily evolution of the CV index, meridional and zonal wind index, etc. all show that these objectively defined beginning and ending dates of the CV and MS rainy periods have climate significance.