两个不同季节台风引发广西特大暴雨的水汽和螺旋度对比分析  

COMPARATIVE ANALYSIS OF MOISTURE AND HELICITY DURING EXTRAORDINARY STORMS CAUSED BY TWO TYPHOONS IN DIFFERENT SEASONS

作　　者：卢小丹[1] 王黎娟[2] 刘国忠 姚学民[1] LU Xiao-dan WANG Li-juan LIU Guo-zhong YAO Xue-min(Baise Meteorological Bureau, Baise 533000, China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster/Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science ＆Technology, Nanjing 210044, China Guangxi Meteorodical Observatory, Nanning 530022, China)

机构地区：[1]百色市气象局,广西百色533000 [2]南京信息工程大学气象灾害预报预警与评估协同创新中心/气象灾害教育部重点实验室,江苏南京210044 [3]广西壮族自治区气象台,广西南宁530022

出　　处：《热带气象学报》2017年第3期375-385,共11页Journal of Tropical Meteorology

基　　金：中国气象局华南区域气象中心科技攻关项目(GRMC2014M13);广西自然科学基金项目(2014GXNSFAA118299)共同资助

摘　　要：利用CMA热带气旋最佳路径数据、NCEP/NCAR再分析资料、广西区域自动气象站观测资料以及中国气象科学数据共享服务网提供的降水资料,对引发广西特大暴雨的深秋台风"海燕"(1330)和盛夏台风"威马逊"(1409)进行对比分析,结果表明:深秋季台风"海燕"特大暴雨中冷空气作用明显,而夏季台风"威马逊"则受西南季风影响较大。由于西南季风的作用,"威马逊"影响广西期间其水汽输送比"海燕"强,"海燕"则完全靠台风本身的水汽输送;而动力条件上,"海燕"则较"威马逊"强,表现为相对风暴螺旋度最大正值中心比"威马逊"大,同时广西上空的水汽辐合层厚度也比"威马逊"要厚得多。广西的降雨开始于东边界水汽输入达到最大值之后开始减小、南边界由水汽输出转为水汽输入且开始出现明显突增现象时,而最强降雨时段则发生在南边界水汽输入达到峰值的前后。相对风暴螺旋度正值中心与强降雨落区有很好的对应关系,并且有至少6 h的提前量,因此,相对风暴螺旋度在台风暴雨预报中可作为一个重要的参考因子。By using the dataset of CM A-STI Tropical Cyclone Optimal Tracks, the NCEP/NCAR reanalysis data, Guangxi regional automatic weather stations observation data and precipitation data provided by China Meteorological Data Sharing Service, typhoons Haiyan（1330） and Ramasun（1409）, which caused extraordinary rainstorms in Guangxi, were analyzed. The results showed that the cold air effect was obvious on the late-autumn typhoon Haiyan, while the summer typhoon Ramasun was influenced by the southwest monsoon. Due to the southwest monsoon, the transfer of water vapor was stronger with Ramasun, which affected Guangxi, than with Haiyan, and the water vapor transfer of Haiyan was totally dependent on its circulation. On the contrary, in terms of dynamic conditions, Haiyan was stronger than Ramasun, its maximum value of the helicity center was also greater, and its moisture convergence layers were thicker over Guangxi. The rains beginning in the eastern boundary of Guangxi started to decrease after reaching the maximum input, and the transfer of water vapor from output transformed into input and began to increase suddenly, while the strongest periods of rainfall occurred around＇ the time when the water vapor input of the southern boundary peaked. The positive helicity center had good corresponding relationship with the heavy rainfall area and were at least six hours in advance, so that the helicity can be used as an important reference factor in forecasting torrential rain caused by typhoons.

关 键 词：特大暴雨 冷空气 西南季风 水汽输送 水汽收支 相对风暴螺旋度 

分 类 号：P458.124[天文地球—大气科学及气象学]