2010年河南两次大暴雨过程中的低涡特征对比分析  

Comparative analysis on low vortex characteristics in two extra heavy rain processes over Henan in July 2010

作　　者：苏爱芳[1,2] 崔丽曼[1,2] 徐文明[1,2] 林琳[3] 

机构地区：[1]中国气象局(河南)农业气象保障与应用技术重点实验室,郑州450003 [2]河南省气象台,郑州450003 [3]中国气象局,北京100081

出　　处：《暴雨灾害》2012年第4期328-335,共8页Torrential Rain and Disasters

基　　金：2009年度公益性行业(气象)科研专项(GYHY20090603);2011年河南省重点科技攻关项目(112102310033)

摘　　要：利用常规气象观测、区域自动站、多普勒雷达等资料及NCEP再分析资料,对2010年7月16—19日河南省连续发生的两次大暴雨过程(分别简称"7.17"过程和"7.19"过程)及其低涡特征进行对比分析。结果表明:"7.17"过程中低涡发展于黄淮西部,而"7.19"过程中低涡为源于四川盆地并在河南境内发展加强的西南涡;副热带高压边缘强盛的西南暖湿气流与北方扩散南下的冷空气相互作用,有利于中尺度低涡形成和发展;远距离台风及副热带高压外围偏南暖湿气流北上为暴雨过程提供了充沛水汽;涡旋中心东南侧的窄带回波造成了暴雨、龙卷等强对流天气,其北侧的东北气流入流区也是强降水集中区域;两次过程能量锋区特征明显,"7.17"过程强降水主要发生在对流不稳定条件下,雨强大,而"7.19"过程强降水主要发生在弱的对流不稳定或中性大气环境中,雨强(1 h)相对较弱;强的低层辐合与高空辐散耦合的动力结构有利于低涡和垂直上升运动发展,也加强了水汽辐合抬升;涡度收支诊断表明,两次过程中低涡均处于旺盛发展阶段,散度项和扭转项是黄淮地区中低层低涡发展的重要因子。The conventional meteorological observations data,regional automatic weather observation station data,Doppler radar data and NCEP/NCAR reanalysis data were used to contrast and analyze the two continuous extra heavy rain processes（hereinafter referred to as ＂7.17＂process and＂7.19＂process respectively） in Henan from July 16 to 19,2010 and the low vortex characteristics in the two processes.The results show that the low vortex in＂7.17＂process developed in the west of the Huanghe-Huaihe region,and the low vortex in＂7.19＂process is Southwest China vortex originated in Sichuan Basin,and later developed and strengthened in Henan.The interaction between strong southwest warm and wet airflow on the edge of subtropical high and cold air spreading from north to south is favorable to form and develop the mesoscale vortex over the western Huanghe-Huaihe region.The typhoon far away and the southerly warm and wet airflow on the edge of subtropical high moving northwards provided sufficient moisture condition for the heavy rain processes.The narrow band echoes in southeast side of vortexes’centre caused severe convective weather such as heavy rain and tornadoes,while the inflow zone with northeast airflow in north side of vortexes’centre is the main region of severe precipitation too.In the two processes,there are distinct energy front zones,however,the severe precipitation in＂7.17＂process was mainly generated under convective instability and,had high rainfall intensity,and the severe precipitation in＂7.19＂process was mainly generated under weak convective instability or neutral stratification and,had relatively weak rainfall intensity.The dynamic structure with coupling of strong convergence in the mid-and low-level and divergence in the upper level is in favor of the development of low vortex and vertical ascending movement,and also can strengthen the convergence and uplift of moisture.Diagnosis on the budget of vorticity shows that vortexes in the two processes are in the stages of vigorous de

关 键 词：暴雨 低涡 不稳定条件 涡度收支 

分 类 号：P458.121.1[天文地球—大气科学及气象学]