微波辐射计在对流天气预报中的应用

选取2016—2018年每年4—9月份RPG-HATPRO型42通道微波辐射计观测的不稳定指数参数(K、SI、CAPE、LI)及水汽参数(IWV、LWP),研究得出各参数触发雷雨大风、短时强降水的阈值条件为K>37℃、SI<-1℃、IWV>60 kg/m~2、LWP>400 g/m~2,而LI、CAPE无法对3种天气类型进行区分。利用费舍判别分析方法,将不稳定指数参数及水汽参数作为预报因子,建立预报方程并进行检验,结果表明:二级判别方程预测对流天气的准确率为76%,可以作为预报对流天气的辅助工具;多级判别方程不能很好地区分3种天气类型,但将其作为修正后的二级判别方程使用,能提高对流天气的测中概率。

The Application of a Microwave Radiometer in the Forecasting of Convective Weather

Instability index parameters(K,SI,CAPE and LI)and water vapor parameters(IWV and LWP),as observed by a 42-channel microwave radiometer(Model RPG-HATPRO)from April to September in 2016 to 2018,are selected to determine their thresholds by which thunderstorms and short-range intense rain are triggered.While K>37℃,SI<-1℃,IWV>60 kg/m~2 and LWP>400 g/m~2,LI and CAPE cannot differentiate them.The Fisher discrimination method is used to take the instability index parameters and water vapor parameters as predictors to formulate a prediction equation and tests are performed.The result is shown as follows.A two-sample discrimination prediction equation has an accuracy rate of 76%for forecasting intense convective weather,making it a supplementary tool for convective weather forecasting.Although a three-sample discrimination equation is less useful in this regard,it can be revised to become a two-sample discrimination equation to increase the hit rate for convective weather.