影响台风“鲇鱼”(2010)强度的环境系统的诊断分析  

Environmental effects on the intensity of typhoon Megi(2010)

作　　者：禹梁玉 方娟[2] 

机构地区：[1]江苏省气象台,南京210008 [2]南京大学中尺度灾害性天气教育部重点实验室,大气科学学院,南京210091

出　　处：《南京大学学报（自然科学版）》2014年第2期113-128,共16页Journal of Nanjing University（Natural Science）

基　　金：国家973项目(2012CB417201)

摘　　要：本文采用日本气象厅的最佳路径数据和美国国家环境预报中心1°×1°逐6h再分析资料,利用分部位涡反演的方法,分析了不同天气系统对台风"鲇鱼"(2010)强度变化的影响.研究结果表明,在"鲇鱼"的生成和发展阶段,西北太平洋副热带高压扰动促进水汽向台风中心输送,为台风增强提供充足的水汽条件;台风自身扰动的增强,其自身的抽吸作用使得高层流场具有较强的辐散特征,同时配合低层强的辐合,有利于"鲇鱼"强度的维持和增强;与此同时,台风自身扰动和西风槽系统扰动共同引导弱冷空气向"鲇鱼"中层入侵,有利于"鲇鱼"内部对流的发展,激发其强度进一步加强.在"鲇鱼"减弱阶段,由于台风自身环流导致水汽流出增多,加上西风槽扰动向台风中心带入的大量干空气,造成"鲇鱼"内部水汽供应不足;"鲇鱼"中心高层流出气流受西风槽扰动以及位于"鲇鱼"南侧的反气旋阻挡,气流辐散减弱,也不利于台风强度的维持.Based on the reanalysis data from the National Centers for Environmental Prediction and best-track data from Japan Meteorological Agency,the influence of various weather systems on the intensity of typhoon Megi is analyzed via the piecewise potential vorticity inversion technique.It is found that,at the intensifying stage of Megi,the transportation of water vapor to typhoon center was promoted by the subtropical high over the northwest Pacific Ocean,which provided necessary moisture for the development of Megi.As Megi intensifies,the divergence in the upper levels was considerably enhanced under the effect of pumping action,which was favorable for the intensification of Megi.In the meanwhile,the westerly trough and the perturbation associated with the typhoon lead to the intrusion of the weak cold air into the circulation of Megi,which advanced the development of convection within Megi.At the weakening stage of Megi,the supply of water vapor became insufficient to sustain the intensification of Megi as a result of the increased upper-level outflow of water vapor associated with the storm and a large amount of dry air intruded into Megi under the influence of the westerly trough.Furthermore,the upper-level divergence was considerably weakened as the outflow was blocked by westerly trough＆amp;nbsp;and anticyclone located in the south side of Megi.All of the above-mentioned factors were unfavorable for the maintenance and intensification of Megi.

关 键 词：台风 位涡反演 副高 西风槽 

分 类 号：P444[天文地球—大气科学及气象学]