The Model Experiment And Analysis Of The Meso-Scale Systems In The Course Of Meiyu Frontal Rainstorm

The meso-scale systems are the direct influencial systems of the Meiyu frontal rainstorm. Because their regional, abrupt characters and the complicated relations to all scales of systems, It's hard to find the causes of their occurrence and development and the rules of their infection on the rainstorm. Adopting high resolution nested grid project and proper physical parameter , A Mei-Yu heavy rain process during eight July 22,2002 and eight July 23,2002 and the meso- B -scale systems alongwith it ,were simulated by use of PSU/NCAR meso-scale nonstatic numerical forecast model MM5 in this paper. The simulation result describes successfully the spatial and temporal distribution of this rain process and the developing course of the concomitant meso- ?-scale systems. The result shows that the dynamic field and thermodynamic field in the zone of the Meiyu front have obvious meso-scale structure characters, the Meiyu frontal rainfall is caused by a series of meso-scale convective systems in the zone of Meiyu front, the dynamic field and thermodynamic field corresponding to the meso-scale convective systems take on evident meso-scale structure, the structure of the dynamic field and thermodynamic field will adjust correspondingly in the course of the development of the meso-scale convective systems, what's more, the adjustments and the changes of the physical parameters will restricted the development and transformation of the meso-scale convective systems in reverse.