2013年湖北一次大暴雨β中尺度分析和模拟诊断  

Simulation and Diagnosis of the Evolution Characteristics of a Meso-β Scale Heavy Rainstorm Event in Hubei in 2013

作　　者：祁海霞[1,2] 辜旭赞[1] 白永清[1] 钟敏[2] 王晓玲[2] 

机构地区：[1]中国气象局武汉暴雨研究所暴雨监测预警湖北省重点实验室,武汉130205 [2]武汉中心气象台,武汉130074

出　　处：《气象》2017年第3期268-277,共10页Meteorological Monthly

基　　金：国家自然科学基金项目(41275106);公益性行业(气象)科研专项(GYHY201106003)共同资助

摘　　要：利用地面加密自动站资料、FY-2E卫星TBB和NCEP/GFS 0.5°×0.5°分析场资料,对2013年7月5—6日发生在湖北鄂东的大范围暴雨过程β中尺度系统活动特征进行了研究,并利用WRF中尺度模式输出的高分辨率资料进行诊断分析。诊断分析表明:该次鄂东大暴雨过程发生在深厚低槽前正涡度区、低空切变线前部急流核附近与高空强辐散气流以及不稳定能量重合区域中,暖湿气团的抬升凝结高度较低,具有较高的降水效率;产生暴雨的直接原因是由3个不同时间和地域的近圆形β中尺度对流系统先后移动经过形成;采用WRF中尺度模式对这次大暴雨过程做了数值模拟,中尺度模式模拟总水物质(水汽+云水+云冰+雨水)通量散度降水牢的诊断分析,得出7月5日夜间β中尺度对流系统中有多个γ小尺度单体活动,此物理量值一定程度上可以定量估算雨团的小时雨强,而模拟最大可能对流可降水率的诊断分析,可以反映雨团内部的水汽、热力条件与降水量之间关系。Based on a variety of densely observed data from automatic surface weather observation system, NCEP/GFS 0.5°×0.5° analysis data, the temperature of black bold （TBB） observed by FY-2E satellite, the evolution of the heavy rainstorm process in Hubei Province during 5-6 July 2013 is analyzed. Using the high-resolution output from WRF model, the evolution of the meso-β scale systems is diagnosed. The results show that the severe convection took place in the overlay zone of positive vorticity in front of trough at 500 hPa, the shear line of low layer near jet flow nucleus, the upper divergence and the instability energy. There were three meso-β scale systems in the large scale favorable weather situations, and the heavy rainfall groups were associated with the development of the convective systems. Considering the coalescence growth of droplets of the saturated water vapor, cloud water and cloud ice, the WRF model diagnosis is discussed through the precipitation rate of flux divergences. We have found four meso-β scale systems in rain-bands from the evening of 5 July to the morning of 6 July 2013, and the physical quantity value could quantitatively estimate the hourly rainfall intensity to some extent. Maximum probable convective precipitation rate could be a better physical quantity value to reflect the relations of the vapor condition in mesoscale rain cluster, thermodynamic condition and rainfall. Thus, it could be applied to the Doppler weather radar nowcasting.

关 键 词：暴雨 对流系统 模拟诊断 通量散度 对流可降水率 

分 类 号：P458[天文地球—大气科学及气象学]