浙东地形对台风性质的影响——以1909号台风“利奇马”为例  

The influences of topography of eastern Zhejiang on typhoon properties—a case study of typhoon"Lekima"(1909)

作　　者：王凯[1] 李渊 高丽 翁之梅[1] 郭九华 WANG Kai;LI Yuan;GAO Li;WENG Zhimei;GUO Jiuhua(Taizhou Meteorological Bureau,Taizhou 318000 China)

机构地区：[1]台州市气象局,浙江台州318000

出　　处：《海洋预报》2022年第1期11-20,共10页Marine Forecasts

基　　金：浙江省气象局预报员专项(2019YBY14)。

摘　　要：采用WRF中尺度模式设计地形敏感性实验,模拟了台风“利奇马”的登陆和降水过程,分析了浙东地形对台风降水、路径、强度和结构等的影响。研究结果表明:浙东地形对台风降水的影响最为显著,浙东区域存在两个明显的雨量大值区,分别对应北侧天台山和四明山,南侧括苍山。区域平均雨量增幅约为50 mm,雨量大值区可达30%。山地地形的强迫作用可以促进低层辐合和垂直上升运动,加强局地台风涡旋,从而增强台风降水并影响降水分布。海岸线喇叭口地形对降水增强也有一定的贡献。在不同的台风降水阶段,地形的影响作用也不同,强降水阶段地形影响更显著,降水效率的差异也越大。沿海小地形可以产生较大的雨量波动,海拔高度越高,雨量越大。环境风场与地形的交角是地形增幅作用的重要影响因素,浙东的北侧区域虽然地形海拔高度低,但是受台风环流的偏东风影响时间更长,雨量增幅比南侧区域更显著。此外,浙东地形在一定程度上能减慢台风移速,减弱台风强度,对台风结构也有一定影响。In this paper,sensitive experiments are conducted using WRF to simulate the landing and precipitation processes of typhoon"Lekima"(1909),and to analyze the influence of topography of eastern Zhejiang Province on typhoon precipitation,path,strength and structure.The results show that the topography of eastern Zhejiang has the most significant influence on typhoon precipitation.There are two significant precipitation areas in eastern Zhejiang Province,which are Tiantai Mountain and Siming Mountain in the north and Kuocang Mountain in the south.The precipitation increase is about 50 mm on regional average with a maximum by 30%in the heavy rainfall area.The forcing effect of mountain topography can promote the low-level convergence and vertical upward movement and strengthen the local typhoon vortex,and thereby increase the typhoon precipitation and affect the precipitation distribution.The horn-like topography also contributes to the enhancement of precipitation.The influence of topography is different in different precipitation stages of typhoon.The influence is more significant in heavy precipitation stage,and the difference of precipitation efficiency is also greater.Small coastal topography can cause large rainfall fluctuations,and the higher the altitude,the greater the rainfall.The intersection angle of the environmental wind and the topography is an important factor affecting the increase of precipitation.Although the altitude on the north side of eastern Zhejiang is low,the increase of precipitation is more significant than that on the south side since it is influenced by the easterly wind of the typhoon circulation for a longer time of period.In addition,the topography of eastern Zhejiang can slow down the typhoon movement to a certain extent,and weaken the typhoon intensity and have a certain impact on the typhoon structure.

关 键 词：数值模拟 地形 台风 强降水 

分 类 号：P444[天文地球—大气科学及气象学]