北京“7.21”特大暴雨天气过程的数值模拟研究
A Numercial Study on Weather Process of Beijing "7.21" Heavy Rainstorm
杨璐 1付延或2
作者信息
- 1. 解放军理工大学气象海洋学院,江苏南京211101
- 2. 总参气象海洋空间天气总站海口地面站,海南海口571100
- 折叠
摘要
采用NCEP1°×1°全球再分析资料和WRF3.2中尺度数值模式,利用天气学分析、中尺度数值模拟和数值模拟输出产品诊断方法,对2012年7月21 ～22日发生在北京地区的特大暴雨天气过程的大尺度环流形势背景及其演变、暴雨中心上空各物理量的时空分布特征以及暴雨发生发展的动力学机制进行了研究.结果表明,暖湿空气在低层辐合形成强烈的上升运动,到高层辐散形成两侧的下沉次级环流,为暴雨的发生创造了必要的动力条件;在此次暴雨过程中,MCC内“列车效应”的产生和多个小型对流单体的形成,导致上升运动更为强烈,从而使得降水持续时间较长;等θse线高能舌从800 hPa一直延伸至600 hPa,触发和加剧不稳定的暖湿气团强烈地上升,为暴雨的发生输送了必要的水汽和位势不稳定能量.源源不断的西南气流在中低层强烈的辐合上升为此次暴雨提供了充足的水汽条件.
Abstract
Based on synoptic analysis,meso-scale simulation and the diagnostic method of numerical simulation output products,a heavy rainstorm occurred in Beijing from July 21 to July 22,2012 was simulated by using WRF3.2 (Weather Research and Forecasting Model) and NCEP (National Center of Enviroment Predicting) reanalyzed data.The large-scale circulation condition and its environment was researched,as well as the spatial and temporal distribution characteristics of each physical quantity above the storm center,and the dynamic mechanism of the heavy rainstorm development.Results showed that humid and warmer air had stronger convergence and upward motion in the lower troposphere and it provided necessary dynamic conditions for the formation of the heavy rain.During this process of rainstorm,the formation of "trains effects" in MCC and the multiple small convective cells led to stronger upward motion,so that the rainfall maintained for a relatively long time.High energy tongue of wet potential temperature extended from 800 to 600 hPa,and triggered unstable warm air rising strongly.As a result,the unstable energy in the atmosphere released and the storms maintained for a long time.The moisture convergence zone below 500 hPa was significant and it provided vapor environment for the heavy rainstorm.
关键词
数值模拟/中尺度暴雨/诊断分析Key words
Numerical simulation/Meso-scale heavy rainstorm/Diagnostic analysis引用本文复制引用
出版年
2016
国家科技期刊平台
NSTL
维普
万方数据