利用Cloudsat卫星资料分析冻雨天气的云结构  

Analysis on the Cloud Structure of Freezing Precipitation Using Cloudsat Satellite Data

作　　者：陈英英[1] 武文辉 唐仁茂[1] 周毓荃[3] 毛节泰[4] 赵姝慧[5] 

机构地区：[1]湖北省人工影响天气办公室,武汉430074 [2]贵州省气象台,贵阳550002 [3]中国气象局人工影响天气中心,北京100081 [4]北京大学物理学院大气与海洋科学系,北京100871 [5]辽宁省人工影响天气办公室,沈阳110001

出　　处：《气象》2011年第6期707-713,共7页Meteorological Monthly

基　　金：国家自然科学基金项目40865003;2010年湖北省气象局科技发展基金项目(2010Q02)共同资助

摘　　要：利用Cloudsat卫星资料中的欧洲中心中期天气预报(ECMWF)温湿度廓线、雷达反射率因子等产品结合探空秒数据和地面观测资料从云物理的角度分析了2008年初发生在我国南方地区的一次典型冻雨天气的云结构特征。分析表明:此次冻雨发生时温度廓线上存在明显的逆温层,但有逆温层并不一定出现冻雨,融化层与次冻结层的相对厚度决定着最终的地面降水类型,沿Cloudsat轨迹10个纬距的范围内出现由雨向冻雨、冰粒、雪的过渡。结合湿度剖面发现,逆温层水汽充沛。ECMWF资料与轨迹上长沙站的探空秒数据对比发现,ECMWF的温度产品要比湿度产品有更高的准确性。毫米波云剖面雷达CPR的反射率因子产品显示,此次冻雨有明显的零度层亮带特征,且亮带刚好出现在0℃等温线上界以下,直观地展示出基于经典"融冰过程"的冻雨形成机理。One severe freezing precipitation occurred over southern China in the early 2008.Using the Cloudsat products（ECMWF and radar reflectivity）,from the cloud physics perspective,the main characteristics of cloud structure are studied based on sounding data and surface observations.The results indicate that there exists an obvious inversion layer,but it is not the only reason for freezing precipitation. Within a 10°latitude band from the Cloudsat orbit,there is a transition region,in the form of rain,freezing rain,ice pellets and snow,which is partially a consequence of size-dependent differences in melting layer and low-level subfreezing region.Combining with the vertical distribution of humidity,it shows that there exists abundant water vapor in the inversion layer.Compared with the soundings of Changsha station which is located at the Cloudsat orbit,the temperature of European Centre for Medium-Range Weather Forecasting（ECMWF） is proved to be more correct than humidity.The radar reflectivity shows that there exists obvious signature of bright band during this freezing precipitation,which is just under the upper limit of 0℃isotherm.The formation mechanism of ＂classical＂ melting process is demonstrated as the cause for freezing precipitation has been shown visually.

关 键 词：CLOUDSAT 冻雨 逆温层 零度层亮带 

分 类 号：P456.2[天文地球—大气科学及气象学]