The Study On The Environmental Physical Field Affecting The Movement And The Propagation Of Mesoscale Convective System

Previous study showed that strong convective weathers, for instance, heavy rainfall, tornado, thunderstorm, etc., have close relationship with the origin and evolution of Mesoscale Convective System (MCS). And the movement and propagation of MCS over the Tibetan Plateau in China have important influence on severe rainstorm and flood disasters of Yangtze River Basin. Therefore, studying the features of spatial-time of MCS over the Tibetan Plateau and the conditions of MCS's origin, evolution and movement out of Tibetan Plateau, is of great meaning to reduce the loss of Yangtze River Basin due to the disaster weather.In this paper, the trajectories of MCS over the Tibetan Plateau in China in summer 1999-2000 are automatically tracked using GMS (Geostationary Meteorological Satellite) brightness temperature (Tbb) by MASCOTTE (Maximum Spatial Correlation Tracking Technique). Based on these, T106 numerical products have been used to find the conditions of environmental physical field values which have effect on the origin and movement of the MCS over the Tibetan Plateau. Furthermore, daily rainfall data of nearly 200 observation stations in Yangtze River Basin are also been used to find the relationship between the trajectories of MCS over the Tibetan Plateau and heavy rainfall process in Yangtze River Basin. These are of important practical value to discover the reason of MCS's origin, development, eastward moving and propagation, so as to reduce the disaster weather loss of Yangtze River Basin.There are six chapters in this paper. Chapter one discusses recent study results of the MCS, based on these, methodology of this paper is provided. In chapter two, using MASCOTTE technique, some information about MCS, including trajectories, size, intensity, shape, life duration etc., are obtained form June to August in 1999 and 2000. We also study the features of spatial-time of MCS over the Tibetan Plateau in summer and the characteristics of MCS's diurnal variation. In chapter three, environmental...