THE FORMATION AND DEVELOPMENT OF A MESOSCALE CONVECTIVE SYSTEM WITH HEAVY RAINFALL ALONG SOUTH CHINA COASTAL AREA  

作　　者：蒙伟光 张艳霞 戴光丰 闫敬华 

机构地区：[1]Guangzhou Institute of Tropical and Marine Meteorology CMA

出　　处：《Journal of Tropical Meteorology》2008年第1期57-60,共4页热带气象学报（英文版）

基　　金：Fundamental Scientific Research Condition, a project of Ministry of Science & Technology(2003DIB4J145);Key Scientific Project for Guangdong Province (2004B32601002)

摘　　要：Observational analysis shows that a Mesoscale Convective System (MCS) occurred on May 13-14 2004 along the coastal area in South China. The MCS initiated among the southwesterly flows within a west-east orientation low-level shear line. Associated with the system, in its subsequent development stages, no distinct vortex circulation developed in low-level. Instead, a cyclonic flow disturbance was observed in the mid-troposphere. How the convection starts to develop and evolve into a MCS With observational analysis and numerical simulation, the problem has been studied. The high-resolution MM5 simulation shows that topographic convergence along the coastal line and the nearby mountains in western South China plays an important role to initiate the MCS convection. Once the convection occurs, due to the condensation heating, a cooperative interaction between the preexisting mid-level disturbance and convection is created, which may greatly affect the MCS development during periods when the system continues moving eastward. Compared to some typical MCS that happen in Southern China, which are usually accompanied with upward development of cyclonic vorticity, the development and evolution of the investigated MCS shows distinguishing features. In this article, the physical mechanisms responsible for the intensification of mid-level disturbance are discussed, and a viewpoint to interpret the effects of mid-level disturbance on the MCS organizational development is proposed.Observational analysis shows that a Mesoscale Convective System （MCS） occurred on May 13 - 14 2004 along the coastal area in South China. The MCS initiated among the southwesterly flows within a west-east orientation low-level shear line. Associated with the system, in its subsequent development stages, no distinct vortex circulation developed in low-level. Instead, a cyclonic flow disturbance was observed in the mid-troposphere. How the convection starts to develop and evolve into a MCS？ With observational analysis and numerical simulation, the problem has been studied. The high-resolution MM5 simulation shows that topographic convergence along the coastal line and the nearby mountains in western South China plays an important role to initiate the MCS convection. Once the convection occurs, due to the condensation heating, a cooperative interaction between the preexisting mid-level disturbance and convection is created, which may greatly affect the MCS development during periods when the system continues moving eastward. Compared to some typical MCS that happen in Southern China, which are usually accompanied with upward development of cyclonic vorticity, the development and evolution of the investigated MCS shows distinguishing features. In this article, the physical mechanisms responsible for the intensification of mid-level disturbance are discussed, and a viewpoint to interpret the effects of mid-level disturbance on the MCS organizational development is proposed.

关 键 词：topographic convergence mid-level disturbance mesoscale convective system （MCS） numericalsimulation 

分 类 号：P426.62[天文地球—大气科学及气象学]