摘要
采用实测资料,对造成7月20日至22日期间的特强暴雨过程进行了分析,认为,除去副热带高压南退且稳定维持这种有利的大尺度条件外,一系列β中尺度天气系统在长江中游(即鄂东河谷地区)的发生发展是造成本次强暴雨的最直接原因,这类系统的发生发展具有很大的局地性和突发性。分析表明,对流层中低层的水汽的大量集中以及对流不稳定条件的存在可能对此类系统发展提供了有利环境,对其启动的机制作了初步的讨论,认为地形的热力强迫及梅雨锋上的中尺度扰动可能对此类系统的发生发展起了触发作用。
The process of the heavy rainfall during the period of 21~22, July 1998 is analyzed using denser observational data, especially satellite data and surface data. It is found that a series of meso-β weather system occurred and developed along the middle reaches of the Yangtze River and caused the severe heavy rainfall in this area. The occurrence and evolution of these weather systems have the characteristics of local phenomena and are also very paroxysmal. It is emphasized that the existence of the convergence of rich water vapor and the condition of convective instability in the middle and low troposphere probably provided the favorable environment for development of heavy rainfall. In addition, the mechanism of mesoscale systems is discussed and the results implied that the thermal forcing of the terrain and the mesoscale disturbances on Meiyu (Baiu) front was probably related with the occurrence and evolution of strong weather systems.
出处
《大气科学》
CSCD
北大核心
2002年第4期526-540,共15页
Chinese Journal of Atmospheric Sciences
基金
国家重点基础研究发展规划项目G1998040907"我国重大气候
天气灾害形成机理
预测理论的研究"第Ⅱ部分
国家自然科学基金资助项目49735180以及"水灾分析
决策支持的数据融合"(ANFAS)项目共同资助
