摘要
利用同一Ｚ－Ｉ关系下地面降水与雷达回波强度的空间最佳匹配思想，提出一种定量测量降水的新方法：考察Ｉ－Ｈ曲线，确定与地面的雨量计资料最相近的Ｉ值的所在高度，然后用此高度上的Ｉ值反演降水。借助于多元回归和逐步回归等数学方法，将红外云图云顶温度及其梯度作为因子，地面降水作为函数，回归出一系列的卫星资料估计降水方程。结合可见光资料又给出若干估计降水的方程，并给出了详细的误差分析。发现降水与很多因子有关，而云顶温度、反照率及云顶温度的时间梯度最为明显。研究表明用多因子方程估计降水效果较好。
According to the concept of optimum space matching between ground rainfall intensity, I , and radar reflectivity factor, Z , for a certain Z H relationship, the paper suggests a new method for quantitative radar observation of precipitation. The height at which radar observations of I based on the given Z H relationship are most close to the collocated raingauge measurements is determined and, then, precipitation retrieval from radar data is based on the radar observations of I at this height. By means of multi variable regression and stepwise regression analyses, a number of models are obtained for precipitation estimation with not only satellite IR imagery information such as cloud top temperature and its gradient but also satellite VIS imagery information. It has been found that precipitation depends on lots of factors of which cloud top temperature, albedo, and temporal gradient of cloud top temperature are most significant. It is concluded that models with more variables would result in better estimation of precipitation.
出处
《南京气象学院学报》
CSCD
1998年第4期729-736,共8页
Journal of Nanjing Institute of Meteorology
基金
国家"八五"攻关项目
