海河流域夏季降水关键区季内演变及其环流配置的定量化分析  

Intraseasonal evolution of the key areas of precipitation in the Haihe River Basin and quantitative analysis of its associated atmospheric circulation during summer

作　　者：何丽烨[1] 程善俊 马宁[1] 郭军[1] HE Liye;CHENG Shanjun;MA Ning;GUO Jun(Tianjin Climate Center,Tianjin 300074,China)

机构地区：[1]天津市气候中心

出　　处：《地理学报》2020年第1期41-52,共12页Acta Geographica Sinica

基　　金：国家重点研发计划(2018YFA0606302);公益性行业(气象)科研专项(重大专项)(GYHY201506001-1)~~

摘　　要：海河流域夏季降水的空间分布具有明显的季节内变化特征,利用海河流域148个地面气象台站逐日降水资料以及NCEP/NCAR再分析资料,分析了流域夏季各月降水关键区的分布变化以及与其对应的大气环流系统的季内配置差异,并定量计算了主要环流系统对季内各月关键区降水的影响作用大小。结果表明:海河流域夏季降水关键区稳定表现出一种季节内变化,即以海河流域东北部滦河和北三河下游台站降水贡献率最大值区为轴心,从初夏(6月)至盛夏(7月和8月),降水关键区在季节内呈顺时针移动,由海河流域东北部移至流域东部和南部再移至流域东部和中部。初夏,东北冷涡活动对流域关键区降水影响最显著,相对贡献率达69.6%;盛夏7月,流域关键区降水异常主要和西太平洋副热带高压(西太副高)脊线位置有关,其相对贡献率在60%以上;8月,西太副高脊线和东亚夏季风指数对流域关键区降水的相对贡献大小相当。海河流域降水关键区在夏季各月的分布变化,与这些环流系统的季内变化路径(南北摆动或向北推进)具有很好的一致性。The precipitation distribution has obvious intraseasonal variation characteristics in the Haihe River Basin(HRB)during summer.In this paper,intraseasonal evolution of the key areas of precipitation in the HRB and its associated atmospheric circulation pattern have been investigated,and the relative contributions of different atmospheric circulation factors to precipitation in the key areas are quantitatively calculated,by using daily precipitation data of 148 meteorological stations over the HRB and NCEP/NCAR reanalysis data.The results present a prominent intraseasonal variation of the key areas of summer precipitation in the HRB.The key areas move clockwise around the lower reaches of the Luanhe River and Beisan River located in the northeastern HRB,which are the maximum contribution areas of station precipitation to the HRB total amount,from early summer(June)to midsummer(July and August).The key areas are distributed in northeast HRB,east and south HRB,east and central HRB along with the movement.During early summer,the activities of the Northeast Cold Vortex(NECV)play a dominant role(relative contribution is 69.6%)in precipitation in the key areas;in July,the anomalous precipitation in the key areas is mainly affected by the ridge line of the Western Pacific Subtropical High(WPSH),with a relative contribution of more than 60%;in August,the ridge line of the WPSH and the East Asian summer monsoon index(EASMI)has an equivalent contribution to precipitation in the key areas.In addition,the monthly significant correlation areas relating to these atmospheric circulation factors for precipitation,are found at the same location as the key areas of precipitation in the HRB,and their intraseasonal changing paths are both accordant with the position changes of the associated atmospheric circulation systems in summer.

关 键 词：海河流域 降水关键区 季内变化 东北冷涡 西太平洋副热带高压脊线 东亚夏季风 

分 类 号：P434[天文地球—大气科学及气象学] P426.6