大气科学学报2025，Vol.48Issue(1)：106-121,16.DOI:10.13878/j.cnki.dqkxxb.20240110003
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
摘要
Abstract
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 sev-eral 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,approxima-ting 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 a-nalysis field.This configuration enhances predictions of precipitation location and intensity while reducing false a-larms for heavy rainfall events. Results demonstrate that assimilating data from both FY-3C and FY-3D satellites provides superior forecasts compared to single satellite assimilation,as network data assimilation increases the quantity of high-quality obser-vations,thereby refining initial conditions and improving short-term weather forecast accuracy.FY-3C-only data assimilation particularly enhances relative humidity forecasts,improving intensity predictions and yielding higher threat scores(TSs)for extreme rainfall.Conversely,while FY-3D-only assimilation enhances wind field forecasts,improving the spatial accuracy of precipitation predictions.The combined FY-3CD satellite data assimi-lation adjusts lower-quality data points,producing more stable forecasts.Future work will extend these efforts by incorporating additional Fengyun satellites for comprehensive network assimilation,aiming to further improve NWP accuracy and optimize the use of satellite observations.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Key words
Southwest China vortex/Fengyun-3 satellite/MWHS-2 radiance/joint assimilation/thinning setting引用本文复制引用
姜祈帆,陈科艺,希爽,张利红,范娇..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[J].大气科学学报,2025,48(1):106-121,16.基金项目
2022年长江流域气象开放基金项目(CJLY2022Y10) （CJLY2022Y10）
国家自然科学基金项目(41905031 （）
42375151) （）
