宁夏南部山区雨雪天气分类模型的构建

Classification Model of Rain and Snow Weather in South Ningxia Mountains

为深入了解宁夏南部山区雨雪天气形成原因,用天气学、统计学和逻辑学方法,分析大量雨雪天气个例中的天气系统配置、物理量数据等。研究结果表明:雨雪天气发生时,参与系统至少有500 hPa冷气压槽(或温度槽)、700 hPa低涡切变和地面冷锋等;冷干空气和暖湿气流路径配置约有7种,地面锋面和700 hPa零度等温线配置情形约有5种,700 hPa温度在零度附近及以下。强雨雪天气发生时,水汽输送好、辐合上升层厚、冷暖对比明显、参与系统多、移动较慢。最后给出3个漏报原因。

In order to better understand the rain and snow weather mechanism in south Ningxia mountains, system configuration and physical quantity data in large numbers of rain and snow weather cases were analyzed by the synoptic,statistics and logic methods.It was concluded as follows： when rain and snow weather occurred, the weather systems at least had 500 hPa cold trough, 700 hPa vortex shear and the surface cold front; there were about 7 kinds of configuration of the cold- dry air and the warm-damp air and about 5 kinds of configuration of the surface cold front and the 700 hPa 0 degree isotherm; the temperature in 700 hPa layer were about 0 degrees or bebow; when strong rain and snow weather occurred, the systems worked together and moved slowly, the water vapor was transported, the rising layer of convergence was thick, and the warm and cold difference was large. Finally, three reasons for omission were given.