陕西关中地区层状云降水及雷达特征分析

Precipitation and Its Characteristic of Radar Echo for Stratiform Clouds in Guanzhong Region of Shaanxi Province

作为人工增雨的一项基础工作,利用陕西关中地区宝鸡等3个雷达站附近共12个气候站1998-2007年2~11月的降水及雷达实测资料,分析了该地区的层状云降水及雷达回波特征。结果表明,（1）关中地区人工增雨的适宜时段为每年的2月5日~11月15日;（2）对层状云降雨的天气形势和雷达回波进行了分类;（3）统计分析了宝鸡雷达站稳定性层状云降雨和混合性层状云降雨雷达回波的最大回波强度、回波顶高度、冷层厚度、暖层厚度、融化层厚度、融化层高度等特征;（4）春、秋季稳定性层状云及混合性层状云冷层厚度大于暖层厚度一倍以上,云层中水汽条件较好,更适合人工增雨作业。

The data from three stations of 711 radar located at Guanzhong region of Shaanxi Province from 1998 to 2007 were analyzed,and the daily precipitation with more than 5 mm from 12 climatological stations near the radar stations were also statistically calculated.The main results are as follow：（1） The suitable period for precipitation enhancement in Guanzhong region is from 5 February to 15 November.（2） The stratiform clouds can be classified as stable stratiform clouds and mixed stratiform clouds according to radar echo and synoptic situations.（3） The radar echo characteristics of two kind stratiform clouds are statistically analyzed,including maximum echo strength,height of echo top,thickness of cold cloud,warm cloud and melting layer.（4） In spring and autumn,cold layer thickness is more one time than warm layer thickness for two kinds of stratiform clouds,and the moisture in the clouds is much rich,it is optimal time to implement artificial rainfall using the air-plane,cannon,rocket.