2010年6月江西一次持续性暴雨过程的定量诊断分析  

A quantitative diagnosis for persistent heavy rain in Jiangxi in June 2010

作　　者：邹海波[1,2] 单九生 易雪婷 ZOU Haibo;SHAN Jiusheng;YI Xueting(Meteorological Disaster Emergency Warning Center of Jiangxi, Nanchang 330046;Meteorological Sciences Institute of Jiangxi Province, Nanchang 330046)

机构地区：[1]江西省气象灾害应急预警中心,南昌330046 [2]江西省气象科学研究所,南昌330046

出　　处：《暴雨灾害》2017年第2期139-146,共8页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(41265003);公益性行业(气象)科研专项(GYHY201106003)

摘　　要：利用常规气象站每6 h一次的降水资料和National Centers for Environmental Prediction(NCEP)Final operational analysis(FNL)资料,运用局地经向环流诊断方程对2010年6月17—20日江西的罕见持续性暴雨的两阶段降雨过程作了定量诊断分析,结果表明:潜热加热是造成两阶段暴雨最为重要的原因,且在第二阶段激发的上升运动明显强于第一阶段;经向温度平流、经向西风动量平流和边界条件对两阶段暴雨过程都有一定的正贡献;平均温度垂直输送和纬向西风动量平流在第一阶段为负贡献,在第二阶段转为正贡献。结合对应天气形势分析发现:500 h Pa青藏高原东南侧浅槽的生成、东移、加深,与减弱东南移的切断低涡合并形成东北西南走向的深厚低压槽(暴雨区位于槽前)是第二阶段潜热加热激发的上升运动较第一阶段强的主要原因;高空西风急流出口区(入口)反气旋切变侧的辐合下沉(辐散抽吸)是平均西风动量纬向平流在第一(二)阶段中为(负)正贡献的主要原因;平均温度由低层向高层(高层向低层)输送是造成平均温度垂直输送在第一(二)阶段中为负(正)贡献的主要原因;中低层暖平流激发的上升运动是平均温度平流在两阶段降雨过程中起正贡献的主要原因。Using operational observation data and National Centers for Environmental Prediction(NCEP)Final operational(FNL)analysisdata,a quantitative diagnosis is carried out for the upward branch of a local meridional circulation over Jiangxi during020017to140018May(first stage)and080019to200020May(second stage).The results show that the upward motion is mainly associated with latent heatingin both the two stages.The stimulated omega is large in second stage(-0.353Pa·s-1)than first stage(-0.212)Pa·s-1.The meridional temperatureadvection,the meridional westerly momentum advection and the boundary conditions have positive contributions,while the vertical transportationof mean temperature and the zonal westerly momentum advection have negative contributions to upward motion in first stage.In additionto the meridional temperature advection,the meridional westerly momentum advection and the boundary conditions,the mean temperaturevertical transportation and the zonal westerly momentum advection have turned positive contributions to upward motion in second stage.The corresponding analyses indicate the following results.(1)The500hPa shallow rough over southeast Tibetan Plateau moving eastward anddeepening,merging to a cut-off low which moved southeastward are the main causes of the upward movement stimulated by the latent heatingenhanced in the second stage.(2)The convergence sinking(divergence pumping)of the upper westerly jet exit(entrance)anticyclone shearside is the main reason for positive(negative)contribution of mean westerly momentum zonal advection in the first(second)stage.(3)The upward(downward)transportation of the mean temperature is the main reason for negative(positive)contribution in the first(second)stage.(4)The warm advection is main reason for the positive contribution in two rainfall stages.

关 键 词：暴雨 定量诊断 潜热加热 西风急流 

分 类 号：P458[天文地球—大气科学及气象学]