利用多普勒天气雷达和探空资料,对2009年3月2日南京的雨雪过程进行了研究,分析了雨雪发展的不同阶段,基本反射率场、基本速度场、基本谱宽场、VWP廓线以及大气要素垂直剖面图的演变特征,分析显示:(1)降雪过程的回波分布连续、具有丝缕状纹理,强度比降雨弱。(2)速度场西北方向有逆风区出现,逆风区持续期间降雪稳定、持续。(3)利用探空资料绘制的大气风矢与位温剖面图可较细致地分析雨雪天气的大气垂直结构特征。(4)雨雪天气过程和大气层结密切相关,K指数、沙氏指数及sθe850-500与雨雪天气的演变有着较好的对应关系。
The rain and snow process occurred in Jiangsu province on March 3,2009 is studied with the Doppler weather radar and sounding data.The variation characteristics of base reflectivity field,velocity field,spectrum width field,VWP wind profilers and vertical profiles of atmospheric elements in the different stages of precipitation development are analyzed.The results show that:(1)The snow reflectivity is continuously distributed,and it is weaker than the rain with silk-like texture;(2)The snow weather process is stable and sustainable when there is an inversion-wind area in the northwest of base wind field.(3) Profiler map of meteorological factors of sounding data could delicately analyze vertical characteristics of atmospheric structure in the rain and snow process.(4)The rain and snow process is closely related to atmospheric stratification,there is a good relationship between K index,Show index,θse850-500 and the evolution of rain and snow weather process.