长江下游地区6—9月暴雨过程延伸期预报的探索  

Exploration of Extended Range Forecast for Rainstorm Process from June to September in the Lower Reaches of the Yangtze River

作　　者：孙国武[1,2] 李震坤[2] 陈伯民[2] 信飞[2] 梁萍 

机构地区：[1]中国气象局兰州干旱气象研究所,甘肃兰州730020 [2]上海市气候中心,上海200030

出　　处：《干旱气象》2017年第5期784-790,796,共8页Journal of Arid Meteorology

基　　金：中国气象局公益性行业(气象)科研专项(GYHY201306030);国家自然科学基金项目(41205060)"江淮梅雨季节10~30天延伸期降水过程可预报性研究"共同资助

摘　　要：通过使用低频天气图上大气低频系统(低频气旋和低频反气旋),分析上海地区(长江下游)的暴雨(≥50 mm)过程发生时段低频系统的地理位置和相互配置,并根据近年75次暴雨过程中每次暴雨过程的低频系统演变,归纳合成得到低频预测模型:一种是长江下游北—西北方为低频反气旋,南—东南方是低频气旋(A型);另一类与A型相反,北—西北方是低频气旋,南—东南方是低频反气旋(B型)。最后分析了低频预测模型的物理意义,表明暴雨发生期有西北向东南同时有东南向西北的低频波列(位势高度和水汽通量)在30°N、120°E附近汇合,引起降水。同时低频系统的维持也与扰动动能有关。The geographical position and configuration of low-frequency systems including low-frequency cyclones and anticyclones during rainstorm processes( ≥50 mm) were analyzed by using low-frequency synoptic map in Shanghai or the lower reaches of the Yangtze River( LRYR). Then two low-frequency prediction models were proposed and applied in operation based on the evolution of low-frequency systems of 75 rainstorm processes in recent years. One is that low-frequency anticyclone exists in the north-northwest of LRYR and low-frequency cyclone exists in the south-southeast( type A),the other is the opposite of type A,which means low-frequency cyclone stands in the north-northwest of LRYR and low-frequency anticyclone exists in the south-southeast. Finally,the physical meaning of low-frequency prediction models was discussed and the results demonstrated that the rainstorms occurred when low-frequency wave trains of geopotential height and water vapor flux from northwest to southeast and southeast to northwest converged over the location of 30°N,120°E and its vicinity region. And the maintenance of low-frequency systems had relation with the intensity of perturbation kinetic energy.

关 键 词：低频气旋 低频反气旋 暴雨过程 水汽通量 

分 类 号：P456[天文地球—大气科学及气象学]