【作者】 钟玮； 张大林； 陆汉城； 田利庆；

【Author】 ZHONG Wei 1,Da-Lin ZHANG 2,3,LU Han-Cheng 1,TIAN Li-Qing 4 1 Institute of Meteorology,PLA University of Science and Technology,Nanjing 211101 2 Department of Atmospheric and Oceanic Science,University of Maryland,College Park,Maryland,20742,U.S.A.3 Institute of Atmospheric Science,Nanjing University of Information Science and Technology,Nanjing 210044 4 Weather Bureau of Hebai Province,Shijiazhuang 050021

【机构】 解放军理工大学气象学院； 马里兰大学大气和海洋科学系； 南京信息工程大学大气科学学院； 河北省气象台；

【摘要】 本文利用台风百合(2001)的高分辨率模式资料,应用PV-ω反演方法,在分析台风准平衡和非平衡垂直环流基本特征的基础上,诊断研究了热力和动力强迫对台风深厚湿对流结构的影响,结果指出:准平衡流能够描述台风中具有较长生命史过程的中尺度对流系统的环流结构,中层大振幅垂直运动主要由准平衡ω方程中凝结潜热释放的热力强迫所决定;台风低层由动力辐合强迫产生的弱对流,对眼墙区深厚湿对流的形成起到触发作用,而高层动力强迫产生的下沉运动则削弱了凝结潜热项的影响,抑制了垂直运动向高层伸展。非平衡垂直环流结构上呈现的短波振荡和快时间尺度调整的时空分布特征表明,它是与重力快波频散过程相联系的非定常环流。分析台风中深厚湿对流形成的物理模型可知,准平衡动力强迫引起的低层弱对流达到一定振幅,则会引起中层水汽相变引起的凝结潜热反馈,使得准平衡和非平衡流叠加形成了眼墙区上升运动的大值中心,加上非平衡垂直环流对动量和热量起到的补偿和调整作用,构成了台风内中尺度深厚湿对流的组织化过程。更多还原

【Abstract】 In this study,the characteristics of quasi-balanced and unbalanced vertical circulations are diagnosed by applying the PV-ω equation system to a high-resolution simulation of Typhoon Nari(2001) in order to gain insight into their relative roles in organizing process of deep moist convection in tropical storms.Results show that quasi-balanced flows represent well the organized circulations in the storm,most of which are associated with latent heat release.Weak updrafts in the eyewall,induced by the low-level dynamic convergence,help trigger deep moist convection in its cyclonic flows,whereas the subsidence,induced by the upper-level dynamic force,counteracts the latent heating-induced updrafts,restraining the upward extension of vertical motion.The spatial and temporal distributions of short waves indicate that the unbalance flow is non-stationary and associated with the dispersion of gravity-inertial wave.It is found that when the low-level weak updrafts caused by the quasi-balanced dynamic forcing are intense enough,the release of latent heat results in the superimposition of quasi-balanced and unbalanced updrafts,which form the strong updrafts in the eyewall.This process,together with the compensating and adjustment processes of unbalanced flows,plays important roles in organizing deep moist convection in tropical storms.更多还原