报告题目：Roles of mesoscale convective systems during formation of tropical cyclones
报告人：Dr. Kevin Cheung
单位：Department of Environment and Geography, and Climate Futures Research Centre
Macquarie University, Sydney, Australia 
报告时间： 2010年6月29日（周二），上午10:30
报告地点：  LPAC会议室（原乒乓球室）

主持人： 高 志 球

摘要：Although various theories exist, tropical cyclone (TC) formation is still one of the mysteries in tropical meteorology. Given the well-recognized multiscale nature of TC formation, recent issues in this area of research concentrate on contribution of mesoscale (100 – 1000 km) convective systems (MCSs) and convective scale (sub-100 km) systems to the formation process (Lee et al. 2008). The physical processes of interest include how MCSs lead to the increase of low-level vorticity in TCs. One possible route is the merging of mid-level mesoscale convective vortices to enable a top-down development (e.g., Ritchie 2003). Another theory involves the interaction of convective scale vortical hot towers to build up vorticity from bottom-up (e.g., Montgomery et al. 2006). In addition, how the unique warm-core structure in TCs develops is another essential problem to understand their formation.Due to availability of affordable high performance computing resources in recent years, the horizontal resolution of most numerical weather prediction (NWP) models is less than 10 km, which represents an increase of about an order of magnitude compared with models one to two decades ago. However, NWP models with such high resolution also require abundance of observations and special methodologies for verification before the simulation results can be used to diagnose the associated physical processes.  Through presentation of simulation results of the formation of several TCs in the western North Pacific, this talk will discuss how the simulation of MCS processes in TCs can be improved, and based on these simulations what we have learnt about the relative role of each MCS and major convective episode during TC formation.