近34年河南首场暴雨时空分布特征及环流背景分析  

Spatial-Temporal Distribution and Impact Analysis of the First Rainstorm in Henan Province over the Recent 34 Years

作　　者：梁钰[1,2] 乔春贵 董俊玲 Liang Yu;Qiao Chungui;Dong Junling(CMA·Henan Key Laboratory of Agrometeorological Support and Application Technique,Zhengzhou 450003,China;Henan Meteorological Observatory,Zhengzhou 450003,China)

机构地区：[1]中国气象局·河南省农业气象保障与应用技术重点开放实验室,郑州450003 [2]河南省气象台,郑州450003

出　　处：《气象与环境科学》2020年第2期26-32,共7页Meteorological and Environmental Sciences

基　　金：国家自然科学基金项目(41475041);河南省科技攻关项目(172102310463);河南省气象局面上项目(KM201901)。

摘　　要：利用19852018年河南省121个国家气象观测站每日20时至次日20时降水资料、常规高空地面观测资料、NCEP1°×1°再分析资料,通过统计和诊断分析方法分析了近34年河南首场暴雨的时空分布特征、影响系统、环流形势和物理量特征。研究结果表明:首场暴雨具有明显的年际变化和月变化特征,主要集中在45月,首场暴雨发生时间有提前的趋势;首场暴雨以全省性降水为主,黄淮之间沿黄及其以北和南部地区是暴雨的三个易发区;暴雨出现频次较多的站点和单日雨量最大的站点基本一致,首场暴雨出现的频次从河南省西北部到东南部逐渐增多。首场暴雨的地面影响系统主要是江淮气旋和江淮倒槽两类,高空影响系统500 hPa以低槽为主,700 hPa受低槽、切变线影响,850 hPa受低涡、切变线影响。江淮气旋类暴雨一般热力、动力条件较好,江淮倒槽类暴雨水汽条件较好。首场暴雨的水汽通量、辐合、辐散条件要优于夏季的,垂直速度略小于夏季的,比湿和不稳定度明显低于夏季的。By using the 20:0020:00 BT daily precipitation data during 19852018 from 121 national meteorological stations in Henan province,the conventional high-level and surface observation data and NCEP 1°×1°reanalysis data as well as the statistical method and diagnostic method,this paper analyzes the spatial-temporal distribution characteristics,impact systems,circulation patterns and physical quantities of the first heavy rains in Henan in the recent 34 years.The results show that the first rainstorms in Henan have obvious inter-annual and monthly variation characteristics,mainly concentrated in April to May,but tend to occur earlier.The first rainstorm is mainly the precipitation over the whole province,and the areas between the Yellow River and the Huaihe River,the areas along and in north of Yellow River and the southern part of Henan are three regions liable to having rainstorm.The locations of the stations with high frequencies of rainstorm and largest amount of daily rainfall are basically consistent,and the frequency of the first rainstorm gradually increases from the northwest to the southeast of the province.The surface impact systems of the first rainstorms are mainly the Jianghuai cyclone and the Jianghuai inverted trough.The upper-air impact systems are mainly the trough at 500 hPa,the trough and shear line at 700 hPa,and the vortex and shear line at 850 hPa.Generally,the thermal and dynamic conditions are favorable in the Jianghuai cyclone rainstorm,while the water vapor conditions are favorable in the Jianghuai inverted trough rainstorm.The water vapor flux,convergence and divergence conditions of the first rainstorm are higher than those of the summer rainstorm,but the vertical velocity is slightly lower than in summer,and the specific humidity and instability are obviously lower than in summer.

关 键 词：首场暴雨 气候特征 江淮气旋 江淮倒槽 物理量诊断 

分 类 号：P458.121.1[天文地球—大气科学及气象学]