风云四号B星(FY-4B)是中国最新一代的静止轨道气象卫星,其资料具有更高的时空分辨率。为了进一步推进FY-4B云导风资料在数值模式中的应用,以FY-4B云导风资料为主要研究对象,结合FY-4A云导风资料进行对比,首先分析了其观测误差的垂直分...风云四号B星(FY-4B)是中国最新一代的静止轨道气象卫星,其资料具有更高的时空分辨率。为了进一步推进FY-4B云导风资料在数值模式中的应用,以FY-4B云导风资料为主要研究对象,结合FY-4A云导风资料进行对比,首先分析了其观测误差的垂直分布情况,以此更新WRFDA(Weather Research and Forecasting model Data Assimilation system)同化系统中默认观测误差,随后进一步探究了云导风资料同化对2022年台风“梅花”的预报影响。研究结果表明:FY-4B云导风资料U、V分量的观测误差整体上小于FY-4A;同化FY-4A云导风资料后,模拟的台风路径逐渐偏西;而同化FY-4B云导风资料使得台风中心动力场信息更加完善,分析场对流层中高层西风增强,预报的台风路径更接近实况;相较于同化FY-4A云导风资料,同化FY-4B云导风资料对降水预报的改善效果更好。展开更多
The Northeast China Cold Vortex(NECV)is a significant atmospheric circulation system that triggers severe weather in mid-to-high latitudes of Asia.Fengyun-4B(FY-4B)satellite provides 15-min atmospheric motion vector(A...The Northeast China Cold Vortex(NECV)is a significant atmospheric circulation system that triggers severe weather in mid-to-high latitudes of Asia.Fengyun-4B(FY-4B)satellite provides 15-min atmospheric motion vector(AMV)and 2-h three-dimensional temperature profiles,enabling unprecedented high spatiotemporal resolution for real-time vortex tracking.This study evaluates the effectiveness of FY-4B AMV and temperature products in tracking 24 NECVs in 2023,among which two strong NECVs in winter and summer 2023 were carefully examined.We first assessed the accuracy of wind speed and direction of the AMVs in the NECV monitoring region by comparing them with radiosonde observations,revealing reasonable correlation coefficients(CC),mean absolute errors(MAE),and root mean square errors(RMSE).NECVs and their centers were identified by using AMV data from four channels(CH09,CH10,CH11,and CH13)within the 200–500-hPa layer,employing the“8-point method”that sets specific criteria for the wind directions at 8 surrounding points to ensure a consistent cyclonic pattern around the central point.The NECV centers identified from AMVs are found to be close(mean distance of 181.9 km)to those determined by ERA5 geopotential height.The retrieved FY-4B temperature data are also evaluated against radiosonde observations,showing a high CC of 0.996 and RMSE of 1.87 K,indicating reliable temperature retrievals for NECV tracking.Based on the FY-4B/Geostationary Interferometric Infrared Sounder(GIIRS)500-hPa temperature,the NECV cold centers are obtained and cross-validated against ERA5 reanalysis temperature at 500 hPa,revealing a mean distance deviation of 140.6 km.The real-time operational NECV monitoring based on the FY-4B AMV and temperature products on high spatiotemporal resolutions in this study provides valuable information for disaster prevention and mitigation.展开更多
文摘风云四号B星(FY-4B)是中国最新一代的静止轨道气象卫星,其资料具有更高的时空分辨率。为了进一步推进FY-4B云导风资料在数值模式中的应用,以FY-4B云导风资料为主要研究对象,结合FY-4A云导风资料进行对比,首先分析了其观测误差的垂直分布情况,以此更新WRFDA(Weather Research and Forecasting model Data Assimilation system)同化系统中默认观测误差,随后进一步探究了云导风资料同化对2022年台风“梅花”的预报影响。研究结果表明:FY-4B云导风资料U、V分量的观测误差整体上小于FY-4A;同化FY-4A云导风资料后,模拟的台风路径逐渐偏西;而同化FY-4B云导风资料使得台风中心动力场信息更加完善,分析场对流层中高层西风增强,预报的台风路径更接近实况;相较于同化FY-4A云导风资料,同化FY-4B云导风资料对降水预报的改善效果更好。
基金Supported by the China Meteorological Administration Northeast China Cold Vortex Research Key Laboratory(2023SYIAEKFZD04)Research Project of China Meteorological Administration Training Centre(2024CMATCQN03 and2024CMATCPY01)。
文摘The Northeast China Cold Vortex(NECV)is a significant atmospheric circulation system that triggers severe weather in mid-to-high latitudes of Asia.Fengyun-4B(FY-4B)satellite provides 15-min atmospheric motion vector(AMV)and 2-h three-dimensional temperature profiles,enabling unprecedented high spatiotemporal resolution for real-time vortex tracking.This study evaluates the effectiveness of FY-4B AMV and temperature products in tracking 24 NECVs in 2023,among which two strong NECVs in winter and summer 2023 were carefully examined.We first assessed the accuracy of wind speed and direction of the AMVs in the NECV monitoring region by comparing them with radiosonde observations,revealing reasonable correlation coefficients(CC),mean absolute errors(MAE),and root mean square errors(RMSE).NECVs and their centers were identified by using AMV data from four channels(CH09,CH10,CH11,and CH13)within the 200–500-hPa layer,employing the“8-point method”that sets specific criteria for the wind directions at 8 surrounding points to ensure a consistent cyclonic pattern around the central point.The NECV centers identified from AMVs are found to be close(mean distance of 181.9 km)to those determined by ERA5 geopotential height.The retrieved FY-4B temperature data are also evaluated against radiosonde observations,showing a high CC of 0.996 and RMSE of 1.87 K,indicating reliable temperature retrievals for NECV tracking.Based on the FY-4B/Geostationary Interferometric Infrared Sounder(GIIRS)500-hPa temperature,the NECV cold centers are obtained and cross-validated against ERA5 reanalysis temperature at 500 hPa,revealing a mean distance deviation of 140.6 km.The real-time operational NECV monitoring based on the FY-4B AMV and temperature products on high spatiotemporal resolutions in this study provides valuable information for disaster prevention and mitigation.
