云顶参数与降水间关系的统计分析和数值模拟

Statistic Analysis and Numerical Simulation on the Relationship between Cloud Top Parameters and Precipetation

利用FY-2C静止卫星云顶物理参数及地面加密雨量观测等,结合MM5中尺度非静力数值预报模式,综合分析了典型层状云降水过程的云系演变和结构特征,揭示了云顶参数与单站雨强之间并不是简单的量化统计关系:即降水大,每小时降水量与云顶高度、有效粒子半径是较好的正相关,与云顶温度是较好的负相关;反之则不尽然,云顶高度高、云顶温度低、有效粒子半径大却不一定降水大。并用模拟结果分析解释了形成这种现象的机理。

Using cloud top physical properties of geostationary satellite, ground rainfall observation, and MM5 numerical simulation, the authors analyse the evolvement and structure of typical stratiform cloud. It shows that the relationship between cloud top physical properties and rainfall intensity at single station is not simply statistic. If rainfall is large, a good positive relationship between rainfall per hour and cloud top height, effective particle radius, and a good negative relationship between rainfall per hour and cloud top temperature, are found. Whereas, higher cloud top height, lower cloud top temperature, and larger effective particle radius cannot always guarantee the larger rainfall. The mechanism of this phenomenon has been explained by numerical simulation.