准全球6—8月雨粒子谱和降水反射率因子分布特征分析  

Basic characteristics of monitoring global DPR Droplet Size Distribution and Precipitation Reflectivity Factor from June to August

作　　者：杨可 傅云飞[1] YANG Ke;FU Yunfei(School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026)

机构地区：[1]中国科学技术大学地球和空间科学学院,合肥230026

出　　处：《暴雨灾害》2023年第5期572-584,共13页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(42230612,42275140)。

摘　　要：获得准全球雨粒子谱(DSD)特征对研究降水具有重要科学意义,并在测雨雷达探测反演降水中具有重要应用价值。利用2014—2020年6—8月美国航空航天局(NASA)戈达德飞行中心(GFSC)提供的2ADPR数据以及欧洲天气预报中心再分析数据(ERA5),分析了准全球DSD参数(粒子中值直径D0、粒子浓度参数dBNw)和降水反射率因子(PRF)的三维结构特征,并对不同纬度带及青藏高原地区DSD参数和PRF三维结构特征的区域差异及海陆差异进行了对比和讨论。结果表明:DSD参数D0和dBNw的空间分布型不同,表现为dBNw大值区(>35)具有小D0(<1 mm),而dBNw低值区(<30)具有大D0(>1.2 mm)。近地面各纬度带上陆地平均D0均大于洋面,但平均dBNw均小于洋面,且热带及北半球地域的海陆差异很大。PRF的垂直分布主要由D0决定,dBNw为次要因子。D0平均垂直分布廓线表明大、中、小降水粒子的主要微物理过程存在差异,dBNw的廓线表明高层平均降水粒子浓度小于低层。和陆地其它区域相比,青藏高原DSD参数和PRF的概率密度分布最为集中,且降水粒子尺度最小、浓度偏低。Obtaining monitoring global droplet size distribution(DSD)is of great scientific significance for the study of precipitation charac⁃teristics and has important applications in retrieving precipitation by precipitation radar.Based on the GPM data provided by NASA’s God⁃dard Flight Center(GFSC)and ERA5 reanalysis data,three-dimensional structure of DPR-derived mass-weighted mean diameter(D0)and normalized intercept parameter(dBNw)of DSD and precipitation reflectivity factor(PRF)from June to August in 2014-2020 were investigat⁃ed.The regional and sea-land differences of DSD parameters and PRF in different latitudinal zones were also analyzed.The results are as fol⁃lows.The spatial distribution patterns of D0 and dBNw are different and the large value region of dBNw(>35)has small D0(<1 mm),while the low value region of dBNw(<30)has large D0(>1.2 mm).The mean D0 over the land surface is larger than that over the ocean,but the mean dBNw is smaller than that over the ocean,and there are great differences between land and sea in the tropics and the northern hemi⁃sphere.The vertical distribution of precipitation reflectivity factor(PRF)is mainly determined by D0,and dBNw is a secondary factor.The D0 mean profile indicates that the main microphysical processes of the large,medium,and small precipitation particles are different.The dBNw profile indicates that the concentration of mean particles in the upper layer is smaller than that in the lower layer.Compared with other terrestrial regions,the distributions of DSD parameters and PRF over the Tibetan Plateau are the most concentrated,and the precipitation particles are smaller in size and lower in concentration.

关 键 词：双频测雨雷达 雨粒子谱 粒子中值直径 粒子浓度参数 反射率因子 

分 类 号：P412.27[天文地球—大气科学及气象学]