基于风云三号卫星组网微波湿度计观测资料的西南涡预报晴空同化初步分析  

Impact assessment of MWHS-2 clear-sky data assimilation from joint Fengyun-3 satellite series on forecasting Southwest China vortex

作　　者：姜祈帆 陈科艺[1] 希爽[2] 张利红[3] 范娇 JIANG Qifan;CHEN Keyi;XI Shuang;ZHANG Lihong;FAN Jiao(School of the Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,China;Earth System Modeling and Prediction Centre,China Meteorological Administration,Beijing 100081,China;Chengdu Plateau Meteorological Research Institute of China Meteorological Administration,Chengdu 610072,China;Guangxi Meteorological Observatory,Nanning 530022,China)

机构地区：[1]成都信息工程大学大气科学学院,四川成都610225 [2]中国气象局地球系统数值预报中心,北京100081 [3]中国气象局成都高原气象研究所,四川成都610072 [4]广西壮族自治区气象台,广西南宁530022

出　　处：《大气科学学报》2025年第1期106-121,共16页Transactions of Atmospheric Sciences

基　　金：2022年长江流域气象开放基金项目(CJLY2022Y10);国家自然科学基金项目(41905031,42375151)。

摘　　要：从2008年5月发射FY-3A星到2023年相继发射FY-3G星和FY-3F星,风云三号极轨系列卫星观测网越发完善,使得卫星资料在时间和空间上的分辨率都得到很大提高,促进了我国数值天气预报的发展。西南涡受复杂地形影响而生成于青藏高原东侧700~850 hPa高度,是影响我国夏季暴雨的主要天气系统。本研究基于WRF模式及WRFDA同化系统,利用FY-3C和FY-3D卫星组网微波湿度计观测资料进行晴空同化试验,并探究不同稀疏化设置对预报的影响。结果表明:与星下点分辨率相近的30 km稀疏化设置对于同化和预报的效果最好;同化卫星组网资料优于单个卫星资料,从而改善预报降水落区,降低大量级降水的虚报率,使降水预报准确率得到提高;单独同化FY-3C星微波湿度计资料对湿度场预报的积极影响更大,而单独同化FY-3D星微波湿度计资料对风场的预报改善更好。Since the launch of the FY-3A satellite in May 2008 and subsequent missions,including the FY-3G for precipitation and the FY-3F until 2023,the Fengyun-3(FY-3)second-generation polar-orbiting satellite series has developed into a comprehensive observation network.This network now operates with early-morning,mid-morning,afternoon,and precipitation-dedicated satellites simultaneously in orbit,significantly enhancing the spatial and temporal resolution of satellite data and supporting advances in numerical weather prediction(NWP)in China.The Southwest China vortex(SWCV),a major weather system contributing to intense summer rainfall in China,forms over the complex terrain east of the Qinghai-Xizang Plateau at 700—850 hPa.This study analyzes a SWCV event from July 21 to 23,2022,which caused heavy rainfall near the Sichuan-Shanxi border,where several stations recorded over 100 mm of precipitation within 24 hours.As the vortex moved eastward,it generated a rainfall belt extending from Chongqing through Hubei,Henan,and Shandong provinces.The research investigates the impact of clear-sky assimilation of FY-3 satellite microwave humidity data on forecasting the SWCV using the WRF model and WRFDA system.Clear-sky assimilation experiments with MWHS-2 observations from FY-3C and FY-3D satellites were conducted to assess optimal thinning distances for data assimilation.The findings show that applying inappropriate thinning distances minimizes observation errors,reduces computational costs and improves forecast accuracy.Specifically,a thinning distance of 30 km,approximating the resolution of the sub-satellite point,optimizes forecast performance by maintaining an effective balance between minimizing spatial correlations in the data and ensuring sufficient observational density to constrain the analysis field.This configuration enhances predictions of precipitation location and intensity while reducing false alarms for heavy rainfall events.Results demonstrate that assimilating data from both FY-3C and FY-3D satellites provide

关 键 词：西南涡 风云三号卫星 MWHS-2辐射率资料 组网同化 稀疏化设置 

分 类 号：P407[天文地球—大气科学及气象学] P45