对流层中层中尺度涡旋在台风榴莲(2001)生成中的作用—数值模拟及验证

西太平洋热带气旋（TC）的生成和季风槽及中尺度对流系统（MCS）的活动有密切关系，但以往这方面的实例数值模拟很少。为了进一步探讨由MCS对流强迫产生的对流层中层中尺度涡旋（MCV）在TC生成中的作用，作者利用非静力平衡的中尺度模式PSU/NCAR MM5对台风榴莲（2001）的生成过程进行了高分辨率（6 km）数值模拟和比较验证。结果表明:模式成功地模拟出榴莲的生成地点，其与MCS的相对位置关系与以往的观测研究结果一致；模拟的TC移动路径、强度变化与最优观测报告比较接近，准确反映了TC未来登陆地点，以及中心气压缓慢下降和迅速下降两个阶段；对云系演变的模拟，成功模拟出了TC初生时的涡旋云系和季风槽中MCS云系的分离现象，以及在TC登陆前达到成熟阶段时出现的台风眼和螺旋云带。此外，模式还成功模拟出中层MCV，它的水平尺度约200 km，位于800~400 hPa之间，具有暖心结构等，均与已有观测结果相近。模式初始场中包含有充分的MCS信息，是模拟取得成功的关键因素之一。

The Role of the Middle Tropospheric Mesoscale Convective Vortex in the Genesis of Typhoon Durian (2001)-Simulation and Verification

Although observations suggest there is a close relationship among the western Pacific tropical cyclones(TC),the monsoon troughs and the mesoscale convective systems(MCS),few real case numerical simulations associated with MCS have been performed.In order to further examine the contribution of middle tropospheric mesoscale convective vortex(MCV) forced convectively by MCS to the TC genesis,a real case numerical simulation of typhoon Durian(2001) is completed using the PSU/NCAR nonhydrostatic mesoscale model(MM5) with a high resolution(6 km).The results show: MM5 captures successfully the location of initial formation of Durian,which has a connection with the location of MCS as indicated by previous observations;the simulated track and evolvement of intensity resemble those of the best observation report,furnishing an accurate forecast of the landfall location,and revealing the slow descending and the sharp descending in the change of central minimum pressure;the simulated radar reflectivity reproduces well the boundary between the TC cloud system and the MCS cloud system in the monsoon trough during the genesis stage,also the eye and spiral cloud bands during the mature stage;the information of MCS included in the initial conditions of MM5 is crucial to this successful simulation.Moreover,the simulation reveals the presence of middle tropospheric MCV that has a 200 km horizontal extent and is located between 800 hPa and 400 hPa with a warm core,which is similar to observations.The verifications enhance the reliability for using the high resolution simulation results to investigate the role of MCV in TC genesis.