“利奇马”台风的特点及极端强降水的成因分析  

The Characteristics of typhoon“Lekima”and the cause of extreme rainfall

作　　者：项素清 周梅 徐亚钦 杜金杉 XIANG Su-qing;ZHOU Mei;XU Ya-qin;Du Jin-shan(Jinhua City Meteorological Bureau of Zhejiang Province,Jinhua 321000 China;Panan County Meteorological Bureau of Zhejiang Province,322300)

机构地区：[1]浙江省金华市气象局,浙江金华321000 [2]浙江省磐安县气象局,浙江磐安322300

出　　处：《海洋预报》2020年第5期76-85,共10页Marine Forecasts

基　　金：浙江省气象局预报员专项(2020YBY11);金华市气象局一般类科技项目(2019-01)。

摘　　要：通过分析自动气象站、雷达、卫星等常规资料和NECP再分析资料,发现台风移动路径上高海温、西南季风输送带和副高南侧偏东急流输送充足的水汽和能量、高层辐散场出流条件好、垂直风切变不大等因素使得1909号台风"利奇马"得以快速发展。重点研究了地形在局地极端强降水中的作用,"利奇马"台风携带的高湿、高能大气为强降水的发生提供了可能的大气环流背景条件。低层强西北急流垂直于东北-西南走向的北山山体,受到山体阻挡后产生强烈的爬升作用,水汽被迫抬升到高空凝结成雨,产生强降水。山体的抬升作用触发了不稳定能量的释放,激发了中尺度雨团的形成;而不断生成的中尺度雨团,导致降水量大。山体的阻挡作用使降水系统移动减慢,降水持续时间变长,从而使累积雨量更大。Based on the data analysis of automatic weather station,radar,satellite and the NECP reanalysis,we find that the fast development of typhoon“Lekima”(1909)is induced by the high sea surface temperature along the typhoon track,the sufficient water vapor and energy transferred by the southwest monsoon conveying belt and the easterly jet south of the subtropical high,the good outflow conditions in the divergent field and small vertical wind shear.Moreover,the effect of the terrain on the extreme rainfall is analyzed in this paper.The high humidity and energy carried by typhoon“Lekima”provides favorable background condition for heavy rainfall.The low-level northwest jet lifts after being blocked by the northeast-southwest trending Beishan Mountain,and the water vapor condenses into rain producing heavy precipitation.The uplifting effect of the mountain triggers the release of unstable energy and stimulates the formation of the mesoscale rain cluster,which causes the heavy rainfall.The blocking effect of the mountain slows down the movement of the precipitation system end and increases the duration of precipitation,which results in greater accumulated rainfall.

关 键 词：极端强降水 地形作用 西北风急流 中尺度雨团 

分 类 号：P444[天文地球—大气科学及气象学]