GPM DPR产品在东北地区两类降水过程中的应用评估

Application evaluation of the GPM DPR products in two types of precipitation processes in northeast China

全球降雨观测计划(Global Precipitation Measurement,GPM)卫星自2014年2月发射以来,为高纬度地区的降水三维观测提供了基础,其搭载的双频星载测雨雷达(Double-frequency Precipitation Radar,DPR)反演的4种降水产品可以为中高纬度地区降水研究提供参考。本文利用GPM DPR提供的4种降水产品(Ka_HS、Ka_MS、Ku_NS和DPR_MS),对东北地区两次不同类型降水天气过程的降水结构特征进行分析,探究其宏微观特征的差异,并对GPM DPR的4种产品性能差异进行对比。结果表明:东北地区春季层状云降水的分布范围很广,大部分降水强度低于4.00 mm·h^(-1),且云系发展较为平缓,而夏季混合性降水的强度分布极其不均,且垂直方向发展较为旺盛,回波顶高度可达12 km。对比4种降水产品发现,Ka_MS降水强度、回波顶高度和降水类型划分都具有明显缺陷;Ka_HS可探测到更多的弱降水样本,但在雨强较大时也会出现严重衰减;Ku_NS能够提供较为可靠的回波顶高度和降水类型划分;DPR_MS产品具有独立表现,其中小于0.50 mm·h^(-1)的弱降水与Ka_HS的相关性较好,大于1.00 mm·h^(-1)的降水与Ku_NS有较好的一致性,此外,DPR_MS对降水和雨滴谱的垂直结构表征最合理。

Since the launch of the Global Precipitation Measurement(GPM)satellite in February 2014,it has provided the foundation for three-dimensional observations of precipitation in high latitudes.The four precipitation products retrieved by the double-frequency precipitation radar(DPR)carried by the GPM satellite can provide a reference for precipitation research in middle and high latitude re⁃gions.In this paper,four kinds of precipitation products(Ka_HS,Ka_MS,Ku_NS and DPR_MS)provided by GPM DPR are used to analyze the precipitation structural characteristics of two different types of precipitation weather processes in northeast China and ex⁃plore the differences in macro and micro characteristics of precipitation,then the performance differences among four precipitation products are further compared.The results show that the spatial distribution of spring stratiform precipitation in northeast China is ex⁃tensive,the precipitation intensity of most samples is less than 4.00 mm·h^(-1),and the cloud system develops relatively gently.While the precipitation intensity distribution of mixed precipitation in summer is highly uneven,the development in the vertical direction is rela⁃tively strong,and the echo top height can reach 12 km.The Ka_MS precipitation product has apparent flaws in precipitation intensity,echo top height and precipitation type classification.The Ka_HS precipitation product can detect more weak precipitation samples but it will also experience severe attenuation when the rain intensity is high.The Ku_NS precipitation product has better detection capabili⁃ties and can provide reliable echo top heights and precipitation type classification.The DPR_MS precipitation product has an indepen⁃dent performance.For weak precipitation intensity less than 0.50 mm·h^(-1),it has a good correlation with the Ka_HS product,and for pre⁃cipitation intensity greater than 1.00 mm·h^(-1),it has a good consistency with the Ku_NS product.In addition,the DPR_MS product has the most reasonable results about the vertical structure of precipitation and the raindrop spectrum.