基于对流参数的洋口港地区雷暴预报方法研究

Research on Lightning Forecast at Yangkou Harbor Based on Convective Indexes

文章分析了洋口港地区2001—2009年4—9月1645个样本22种对流参数与雷暴事件的相关性以及这些参数的统计特征。结果表明,各对流参数月际分布差异较大,各参数与雷暴事件相关系数也不同。因而选择沙氏指数SI、全总指数TT、杰弗逊指数JI、抬升凝结高度温度tcl_t、上下层温差dt_58、大气可降水量p_w、风暴强度指数SSI等7个对于雷暴活动具有较好相关性的因子,并考虑到4—9月月际分布差异,使用不同月份p_w、SI、TT、JI的不同阈值作为排空因子,不同月份SSI、tcl_t、dt_58的不同阈值作为预报因子,使用二级逻辑回归法建立排空方程和预报方程,同时对所建立各月预报方程进行了检验和拟合结果分析,并对2010年4—9月样本进行试报,预报效果较好。

This paper analyzed statistical characteristics of 22 convective indexes in the 1645 samples from April to September, 2001--2009 at Yangkou Harbor and their correlation with lightning activities. The re- sults have shown the monthly variations and different coefficients of the indexes, and then the elimination and forecasting equations were set up by means of hi-level logistic regression using the multiple thresholds of indexes Pw, SI, TT, JI for elimination and those of SSI, tclt, dr_58 for prediction with consideration of monthly diversity of each index which is in close correlation with lightning activities. The fitting test has confirmed good forecasting effects of the equations above.