登陆热带风暴“Bilis”维持和暴雨增幅与低纬水汽输送的关系及其数值试验  

NUMERICAL SIMULATION OF THE RELATIONSHIP BETWEEN THE MAINTENANCE AND INCREASE IN HEAVY RAINFALL FROM THE LANDING TROPICAL STORM “BILIS” AND MOISTURE TRANSPORT FROM LOW LATITUDES

作　　者：戴竹君[1,2] 王黎娟[1] 管兆勇[1] 庞玥[1] 何洁琳[3] 黄小梅[1] 

机构地区：[1]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/气象灾害省部共建教育部重点实验室,江苏南京210044 [2]南京市气象局,江苏南京210009 [3]广西壮族自治区气候中心,广西南宁530022

出　　处：《热带气象学报》2014年第1期45-54,共10页Journal of Tropical Meteorology

基　　金：国家重点基础研究发展计划(2009CB421505);江苏省自然科学基金项目(BK20131432);江苏省"青蓝工程";江苏省"333"工程;江苏省高校优势学科建设工程资助项目(PAPD)共同资助

摘　　要：采用WRF中尺度数值模式、NCEP／NCAR再分析资料、地面加密观测资料和JMA最佳路径数据集对0604号强热带风暴“Bilis”的水汽输送特征进行诊断分析与数值模拟。结果表明，“Bilis”登陆后，一直与低纬水汽通道相联结，索马里和80—100°E越赤道气流异常活跃，将大量水汽输送到“Bilis”环流中，有利于其在陆上长久维持并引发沿途暴雨增幅。对“Bilis”的维持过程进行数值模拟和水汽敏感性试验结果显示，低纬水汽输送的减弱不利于登陆热带风暴“Bilis”的维持和暴雨增幅，索马里和80～100°E越赤道气流的持续水汽补充有助于“Bilis”环流在陆上长久维持，减少外界水汽尤其是索马里越赤道气流的水汽输送后，TC暴雨强度和范围衰减十分剧烈。来自低纬水汽输送减弱不利于热带风暴中的强对流活动，不利于“Bilis”获得能量长久维持，雨量也随之相应减少。By using the WRF（weather research and forecasting） mesoscale numerical model, the dataset of NCEP/NCAR reanalysis, Japan Meteorological Agency （JMA） tropical cyclone tracks and intensive surface observations, the moisture transport features of tropical storm Bilis （coded 0604） are diagnosed and simulated. It shows that the cross-equatorial flows in 80- 100 °E and Somali were active after Bilis came ashore, leading to strong water vapor flux into the tropical storm, which helped maintain it and increase its rainfall. The simulation suggested that the decrease of water vapor from low latitudes is not favorable for the maintenance of Bilis and the increase in rainfall. The cross-equatorial flows at 80- 100 °E and Somali were in favor of the maintenance of cyclonic circulation. Cutting off the moisture supply from the Somali jet stream can remarkably weaken the precipitation from Bilis. The decrease of water vapor from low latitudes can remarkably weaken rainfall in corresponding areas due to weakened convection which plays a major role in typhoon maintenance.

关 键 词：热带风暴“Bilis” 水汽输送 数值试验 暴雨增幅 

分 类 号：P423.5[天文地球—大气科学及气象学]