针对搭载于风云三号C星（FY-3C）上的微波湿温探测仪（Microwave Humidity and Temperature Sounder,MWHTS）,建立了海洋晴空大气条件下温湿廓线同时反演的一维变分反演系统.通过对影响反演精度的各个因素进行分析,确立了该系统的输入参...针对搭载于风云三号C星（FY-3C）上的微波湿温探测仪（Microwave Humidity and Temperature Sounder,MWHTS）,建立了海洋晴空大气条件下温湿廓线同时反演的一维变分反演系统.通过对影响反演精度的各个因素进行分析,确立了该系统的输入参数.对于FY-3C/MWHTS观测亮温与快速辐射传输（Radiative Transfer Model for TOVS,RTTOV）模型的模拟亮温之间的偏差和角度依赖性,采用逐像元统计回归校正方法进行校正.选择西北太平洋海域晴空条件下的校正亮温数据进行温湿廓线的反演,并利用欧洲中期天气预报中心再分析数据集对反演结果进行验证,结果表明：反演的温度廓线和相对湿度廓线的最大平均偏差分别为1.09K和5.4%,最大均方根误差分别为1.48K和22.69%,与未校正亮温的反演结果相比,温度廓线的均方根误差最大可减小1.56K,湿度廓线的均方根误差最大可减小14.71%.反演温湿廓线与背景廓线的精度对比表明：反演的温度廓线在10~70hPa、300~350hPa和700~850hPa内的精度高于背景廓线的精度,而反演湿度廓线的精度除了825~875hPa,其他范围均高于背景廓线的精度,因此FY-3C/MWHTS观测亮温的反演结果可进一步提高预报廓线精度.展开更多
由中国风云三号C星(FY-3C)搭载的微波温湿探测仪(MWHTS)的亮温观测资料能够实时反演得到高分辨率、高精度的海面气压场。基于三维变分同化方法将FY-3C/MWHTS观测资料反演的海面气压场同化进入中尺度天气研究与预报(Weather Research and...由中国风云三号C星(FY-3C)搭载的微波温湿探测仪(MWHTS)的亮温观测资料能够实时反演得到高分辨率、高精度的海面气压场。基于三维变分同化方法将FY-3C/MWHTS观测资料反演的海面气压场同化进入中尺度天气研究与预报(Weather Research and Forecasting,WRF)模式,以台风“Maria”和“Noru”为例,通过控制实验和同化试验的对比分析,探讨了同化反演的海面气压场对台风数值预报的影响。初始化敏感性试验结果表明,同化海面气压场使初始时刻台风中心气压与位置更接近实况,并且调整了台风初始温度场和风场的结构和分布。台风的数值预报结果表明:同化反演的海面气压场能够改进台风的路径和强度预报精度。展开更多
The mesoscale numerical model WRF is used to simulate the No. 8 hurricane Matthew in 2016. The radar and radiometer observations are assimilated by WRF Var. With the verification to the real situation, the process of ...The mesoscale numerical model WRF is used to simulate the No. 8 hurricane Matthew in 2016. The radar and radiometer observations are assimilated by WRF Var. With the verification to the real situation, the process of the hurricane rainstorm is well simulated by WRF in this case that it could basically show the hurricane evolution. We use the simulation results which are model outputs with high spatial and temporal resolution to do diagnostic analysis on the short term heavy rainstorm caused by Matthew, with a comparison between the best track and forecasting tracks using active and passive microwave observations from WRFDA model. In order to analyze the inner structure, the nadiral satellite-based observations were matched between the Microwave Humidity and Temperature Sounder (MWHTS) instrument aboard the FY-3C polar-orbiting platform since Sept 30, 2013 and dual-frequency radar named PR aboard GPM satellite and then separate retrievals are demonstrated in data assimilation for extreme weather with the retrieved root-mean-square errors of about 0.9 K and 17% and 10 mm/h for precipitation products, which demonstrates the impact of 118 GHz observations in data assimilation model.展开更多
The Microwave Humidity and Temperature Sounder(MWHTS)is the main payload of FengYun 3D(FY-3D),designed for atmospheric humidity and temperature sounding,and also for monitoring severe weather systems such as typhoons ...The Microwave Humidity and Temperature Sounder(MWHTS)is the main payload of FengYun 3D(FY-3D),designed for atmospheric humidity and temperature sounding,and also for monitoring severe weather systems such as typhoons and rainstorms which will be launched in 2016.Before the launch of MWHTS,a series of experiments will be conducted in normal environment and a thermal/vacuum(T/V)chamber to determine radiometric characteristics of each channel,which are of very importance before the launch.In this paper,design and component description,as well as technical specifications and test results for RF and IF,will be provided.Then T/V calibration results,such as bandwidth correction,nonlinear error,calibration accuracy and sensitivity for all channels.展开更多
The paper develops a passive sub-millimeter precipitation retrievals algorithm for Microwave Humidity and Temperature Sounder(MWHTS)onboard the Chinese Feng Yun 3C(FY-3C)satellite.The retrieval algorithm employs a num...The paper develops a passive sub-millimeter precipitation retrievals algorithm for Microwave Humidity and Temperature Sounder(MWHTS)onboard the Chinese Feng Yun 3C(FY-3C)satellite.The retrieval algorithm employs a number of neural network estimators trained and evaluated using the validated global reference physical model NCEP/WRF/ARTS,and works for seawater.NCEP data per 6 hours are downloaded to run the Weather Research and Forecast model WRF,and derive the typical precipitation data from the whole world.The Atmospheric Radiative Transfer Simulator ARTS is feasible for performing simulations of atmospheric radiative transfer.Rain detection algorithm has been used to generate level 2 products.Retrievals are reliable for surface precipitation rate higher than 0.1 mm/h at 15km resolution,which is in good agreement with those retrieved using the Precipitation retrieval algorithm version 1(ATMP-1)for Advanced Technology Microwave Sounder(ATMS)aboard Suomi NPP satellite.展开更多
For Microwave Humidity and Temperature sounder(MWHTS) measurements over the ocean, a cloud filtering method is presented to filter out cloud-and precipitation-affected observations by analyzing the sensitivity of the ...For Microwave Humidity and Temperature sounder(MWHTS) measurements over the ocean, a cloud filtering method is presented to filter out cloud-and precipitation-affected observations by analyzing the sensitivity of the simulated brightness temperatures of MWHTS to cloud liquid water, and using the root mean square error(RMSE)between observation and simulation in clear sky as a reference standard. The atmospheric temperature and humidity profiles are retrieved using MWHTS measurements with and without filtering by multiple linear regression(MLR),artificial neural networks(ANN) and one-dimensional variational(1DVAR) retrieval methods, respectively, and the effects of the filtering method on the retrieval accuracies are analyzed. The numerical results show that the filtering method can improve the retrieval accuracies of the MLR and the 1DVAR retrieval methods, but have little influence on that of the ANN. In addition, the dependencies of the retrieval methods upon the testing samples of brightness temperature are studied, and the results show that the 1DVAR retrieval method has great stability due to that the testing samples have great impact on the retrieval accuracies of the MLR and the ANN, but have little impact on that of the 1DVAR.展开更多
As a typical physical retrieval algorithm for retrieving atmospheric parameters,one-dimensional variational(1 DVAR)algorithm is widely used in various climate and meteorological communities and enjoys an important pos...As a typical physical retrieval algorithm for retrieving atmospheric parameters,one-dimensional variational(1 DVAR)algorithm is widely used in various climate and meteorological communities and enjoys an important position in the field of microwave remote sensing.Among algorithm parameters affecting the performance of the 1 DVAR algorithm,the accuracy of the microwave radiative transfer model for calculating the simulated brightness temperature is the fundamental constraint on the retrieval accuracies of the 1 DVAR algorithm for retrieving atmospheric parameters.In this study,a deep neural network(DNN)is used to describe the nonlinear relationship between atmospheric parameters and satellite-based microwave radiometer observations,and a DNN-based radiative transfer model is developed and applied to the 1 DVAR algorithm to carry out retrieval experiments of the atmospheric temperature and humidity profiles.The retrieval results of the temperature and humidity profiles from the Microwave Humidity and Temperature Sounder(MWHTS)onboard the Feng-Yun-3(FY-3)satellite show that the DNN-based radiative transfer model can obtain higher accuracy for simulating MWHTS observations than that of the operational radiative transfer model RTTOV,and also enables the 1 DVAR algorithm to obtain higher retrieval accuracies of the temperature and humidity profiles.In this study,the DNN-based radiative transfer model applied to the 1 DVAR algorithm can fundamentally improve the retrieval accuracies of atmospheric parameters,which may provide important reference for various applied studies in atmospheric sciences.展开更多
文摘针对搭载于风云三号C星（FY-3C）上的微波湿温探测仪（Microwave Humidity and Temperature Sounder,MWHTS）,建立了海洋晴空大气条件下温湿廓线同时反演的一维变分反演系统.通过对影响反演精度的各个因素进行分析,确立了该系统的输入参数.对于FY-3C/MWHTS观测亮温与快速辐射传输（Radiative Transfer Model for TOVS,RTTOV）模型的模拟亮温之间的偏差和角度依赖性,采用逐像元统计回归校正方法进行校正.选择西北太平洋海域晴空条件下的校正亮温数据进行温湿廓线的反演,并利用欧洲中期天气预报中心再分析数据集对反演结果进行验证,结果表明：反演的温度廓线和相对湿度廓线的最大平均偏差分别为1.09K和5.4%,最大均方根误差分别为1.48K和22.69%,与未校正亮温的反演结果相比,温度廓线的均方根误差最大可减小1.56K,湿度廓线的均方根误差最大可减小14.71%.反演温湿廓线与背景廓线的精度对比表明：反演的温度廓线在10~70hPa、300~350hPa和700~850hPa内的精度高于背景廓线的精度,而反演湿度廓线的精度除了825~875hPa,其他范围均高于背景廓线的精度,因此FY-3C/MWHTS观测亮温的反演结果可进一步提高预报廓线精度.
文摘由中国风云三号C星(FY-3C)搭载的微波温湿探测仪(MWHTS)的亮温观测资料能够实时反演得到高分辨率、高精度的海面气压场。基于三维变分同化方法将FY-3C/MWHTS观测资料反演的海面气压场同化进入中尺度天气研究与预报(Weather Research and Forecasting,WRF)模式,以台风“Maria”和“Noru”为例,通过控制实验和同化试验的对比分析,探讨了同化反演的海面气压场对台风数值预报的影响。初始化敏感性试验结果表明,同化海面气压场使初始时刻台风中心气压与位置更接近实况,并且调整了台风初始温度场和风场的结构和分布。台风的数值预报结果表明:同化反演的海面气压场能够改进台风的路径和强度预报精度。
文摘The mesoscale numerical model WRF is used to simulate the No. 8 hurricane Matthew in 2016. The radar and radiometer observations are assimilated by WRF Var. With the verification to the real situation, the process of the hurricane rainstorm is well simulated by WRF in this case that it could basically show the hurricane evolution. We use the simulation results which are model outputs with high spatial and temporal resolution to do diagnostic analysis on the short term heavy rainstorm caused by Matthew, with a comparison between the best track and forecasting tracks using active and passive microwave observations from WRFDA model. In order to analyze the inner structure, the nadiral satellite-based observations were matched between the Microwave Humidity and Temperature Sounder (MWHTS) instrument aboard the FY-3C polar-orbiting platform since Sept 30, 2013 and dual-frequency radar named PR aboard GPM satellite and then separate retrievals are demonstrated in data assimilation for extreme weather with the retrieved root-mean-square errors of about 0.9 K and 17% and 10 mm/h for precipitation products, which demonstrates the impact of 118 GHz observations in data assimilation model.
文摘The Microwave Humidity and Temperature Sounder(MWHTS)is the main payload of FengYun 3D(FY-3D),designed for atmospheric humidity and temperature sounding,and also for monitoring severe weather systems such as typhoons and rainstorms which will be launched in 2016.Before the launch of MWHTS,a series of experiments will be conducted in normal environment and a thermal/vacuum(T/V)chamber to determine radiometric characteristics of each channel,which are of very importance before the launch.In this paper,design and component description,as well as technical specifications and test results for RF and IF,will be provided.Then T/V calibration results,such as bandwidth correction,nonlinear error,calibration accuracy and sensitivity for all channels.
文摘The paper develops a passive sub-millimeter precipitation retrievals algorithm for Microwave Humidity and Temperature Sounder(MWHTS)onboard the Chinese Feng Yun 3C(FY-3C)satellite.The retrieval algorithm employs a number of neural network estimators trained and evaluated using the validated global reference physical model NCEP/WRF/ARTS,and works for seawater.NCEP data per 6 hours are downloaded to run the Weather Research and Forecast model WRF,and derive the typical precipitation data from the whole world.The Atmospheric Radiative Transfer Simulator ARTS is feasible for performing simulations of atmospheric radiative transfer.Rain detection algorithm has been used to generate level 2 products.Retrievals are reliable for surface precipitation rate higher than 0.1 mm/h at 15km resolution,which is in good agreement with those retrieved using the Precipitation retrieval algorithm version 1(ATMP-1)for Advanced Technology Microwave Sounder(ATMS)aboard Suomi NPP satellite.
基金Key Fostering Project of National Space Science Center,Chinese Academy of Sciences(Y62112f37s)National 863 Project of China(2015AA8126027)
文摘For Microwave Humidity and Temperature sounder(MWHTS) measurements over the ocean, a cloud filtering method is presented to filter out cloud-and precipitation-affected observations by analyzing the sensitivity of the simulated brightness temperatures of MWHTS to cloud liquid water, and using the root mean square error(RMSE)between observation and simulation in clear sky as a reference standard. The atmospheric temperature and humidity profiles are retrieved using MWHTS measurements with and without filtering by multiple linear regression(MLR),artificial neural networks(ANN) and one-dimensional variational(1DVAR) retrieval methods, respectively, and the effects of the filtering method on the retrieval accuracies are analyzed. The numerical results show that the filtering method can improve the retrieval accuracies of the MLR and the 1DVAR retrieval methods, but have little influence on that of the ANN. In addition, the dependencies of the retrieval methods upon the testing samples of brightness temperature are studied, and the results show that the 1DVAR retrieval method has great stability due to that the testing samples have great impact on the retrieval accuracies of the MLR and the ANN, but have little impact on that of the 1DVAR.
基金National Natural Science Foundation of China(41901297,41806209)Science and Technology Key Project of Henan Province(202102310017)+1 种基金Key Research Projects for the Universities of Henan Province(20A170013)China Postdoctoral Science Foundation(2021M693201)。
文摘As a typical physical retrieval algorithm for retrieving atmospheric parameters,one-dimensional variational(1 DVAR)algorithm is widely used in various climate and meteorological communities and enjoys an important position in the field of microwave remote sensing.Among algorithm parameters affecting the performance of the 1 DVAR algorithm,the accuracy of the microwave radiative transfer model for calculating the simulated brightness temperature is the fundamental constraint on the retrieval accuracies of the 1 DVAR algorithm for retrieving atmospheric parameters.In this study,a deep neural network(DNN)is used to describe the nonlinear relationship between atmospheric parameters and satellite-based microwave radiometer observations,and a DNN-based radiative transfer model is developed and applied to the 1 DVAR algorithm to carry out retrieval experiments of the atmospheric temperature and humidity profiles.The retrieval results of the temperature and humidity profiles from the Microwave Humidity and Temperature Sounder(MWHTS)onboard the Feng-Yun-3(FY-3)satellite show that the DNN-based radiative transfer model can obtain higher accuracy for simulating MWHTS observations than that of the operational radiative transfer model RTTOV,and also enables the 1 DVAR algorithm to obtain higher retrieval accuracies of the temperature and humidity profiles.In this study,the DNN-based radiative transfer model applied to the 1 DVAR algorithm can fundamentally improve the retrieval accuracies of atmospheric parameters,which may provide important reference for various applied studies in atmospheric sciences.
