Abstract:

Based on ERA-Interim reanalysis data from ECMWF (European Centre for Medium-Range Weather Forecasts), precipitation retrieval products 3B42RT from tropical rainfall measuring mission (TRMM) satellite, measured data by Dual-frequency Precipitation Radar (DPR) on board global precipitation measurement (GPM) satellite, FY-2F cloud classification (CLC) and black body temperature (TBB) products, the southwest vortexes affecting precipitation in central-eastern China from April to October (the warm season) during 2010-2020 were analyzed. The results show that there were 108 cases of southwest vortexes moving out of the origin along different paths, and the eastward movement type, northeastward movement type and southeastward movement type accounted for 58.3%, 27.8% and 12.0%, respectively. The eastward movement type southwestern vortex mainly impacted the middle and lower reaches of the Yangtze, with the main rain-band distributing in an east-west orientation. In contrast, the major rain-band of the northeastward movement type southwestern vortex was located in the area from Huai River basin to North China, while the precipitation of the southeastward movement type southwestern vortex concentrated in south China and its coastal. In addition, the precipitation cloud characteristics of these three types of moving-out southwest vortex were distinctly different. The eastward movement type southwestern vortex affecting Jiangnan area tended to generate different precipitation types in different areas, dominated by cumulus clouds to the south of 30 °N, and by stratiform rainfall to the north. Meanwhile, the northeastward movement type southwestern vortex generated precipitation was a combination of convective and stratiform rainfall (i.e., mixed precipitation), with convective-stratiform mixed cloud precipitation. The southeastward movement type southwestern vortex precipitation was dominated by convective precipitation. The vortex precipitation cloud mainly consisted of cumulonimbus and dense cirrus clouds, with high extension height and low TBB. The eastward movement type and the northeastward movement type southwestern vortex both had wide cloud area, while the southeastward movement type southwestern vortex cloud was massive and dense.

Key words: TRMM, GPM, FY-2F, moving-out southwest vortex, rain-band, cloud feature

摘要：

利用欧洲中期天气预报中心提供的ERA-Interim再分析资料、热带降雨测量（tropical rainfall measuring mission,TRMM）卫星提供的降水反演产品3B42RT、全球降雨观测（global precipitation measurement,GPM）卫星搭载的双频降雨雷达（dual-frequency precipitation radar,DPR）观测数据、FY-2F云类型和云顶亮温等资料,对2010—2020年4—10月（暖季）影响中国中东部降水的西南涡进行分析。结果表明,2010—2020年暖季移出型西南涡共计108例,东移型、东北移型和东南移型占比分别为58.3%、27.8%、12.0%。其中东移型西南涡主要影响长江中下游,雨带呈东西向分布;东北移型西南涡雨带主要位于黄淮到华北一带;东南移型西南涡降水则主要集中在华南及沿海海域。另外,3类暖季移出型西南涡降水云系特征有明显差异,东移型西南涡30°N以北为层状云降水,以南为对流云降水,东北移型为对流云和层状云降水共同影响（即混合性降水）,而东南移型则以对流云降水为主;暖季移出型西南涡降水云分类均以积雨云和密卷云为主,且伸展高度高、云顶亮温低,其中东移型和东北移型西南涡云系影响范围更广,而东南移型西南涡云系则呈块状、更密实。

关键词: TRMM, GPM, FY-2F, 移出型西南涡, 雨带, 云系特征