一次西南涡致洪暴雨天气过程诊断分析和数值模拟试验  

Diagnostic Analysis and Numerical Simulation of Rainstorm by Southwest Vortex

作　　者：方从羲 李子良[1] 

机构地区：[1]中国海洋大学海洋与大气学院,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2016年第5期14-21,共8页Periodical of Ocean University of China

基　　金：全球变化研究国家重大科学研究计划项目(2015CB953900);国家自然科学基金项目(41176005);海洋公益性科研专项(GYHY201105018);气象公益性科研专项(GYHY201306016)资助~~

摘　　要：基于NCEP(National Centers for Environmental Prediction)的FNL(Final Operational Global Analysis)资料和WRF-ARW模式,对2014年7月10—12日西南涡(SWV)暴雨天气过程进行诊断分析和数值模拟试验。研究结果表明,西南涡沿切变线东移发展和低空西南急流的增强是导致此次暴雨过程的主要原因。西南涡的移向和相对风暴螺旋度(SRH)大值区有很好对应关系,SRH大值区对西南涡暴雨过程强对流的落区有较好的指示作用。沿西南涡移动方向,其前部暖平流后部冷平流有利于其前移,沿假相当位温平流场的零等值线可指示西南涡的移向。引入湿螺旋度散度(MHD)来分析西南涡降水的水汽条件发现,模式结果计算的850hPa上MHD值分布与雨区和降雨强度对应较好,但对于降水的定量预测还需考虑MHD大值区延伸的高度。Basing on the FNL（Final Operational Global Analysis）data of NCEP（National Centers for Environmental Prediction）and WRF（Weather Research Forecasting）-ARW（Advanced Research WRF）model,a case study of the rainstorm occurred on 10—12July,2014 is carried out by using diagnostic analysis and numerical simulation methods.Research indicates that primary causes of the heavy rain are SWV（southwest China vorticity）eastward movement and development along the shear line and enhancement of low-level jet.In the research of FNL data diagnostic analysis and numerical simulation,the large SRH（storm-relative helicity）areas all correspond directly with the moving direction of SWV.And the large SRH areas still indicate where the severe convection occurs in the process of SWV rainstorm well by analysis of numerical simulation.According to the consequence of FNL data analysis,along the moving direction of SWV,warm advection in front of SWV and cold in the rear is favor of its forward movement.So the zero isolines of potential pseudo-equivalent temperature advection by simulation can indicate the moving direction of SWV.By introducing MHD（moisture helicity divergence）to analysis the water vapor conditions of heavy rain caused by SWV.The research finds that the large areas of simulated MHD at 850 hPa correspond well with the distribution and intensity of precipitation and,the extended height of large MHD areas should be taken into account to improve the forecast of precipitation.

关 键 词：西南涡 WRF-ARW模式 相对风暴螺旋度(SRH) 假相当位温 湿螺旋度散度(MHD) 

分 类 号：P468.024[天文地球—大气科学及气象学]