The key factors of temporal and spatial resolution for typhoon observation played an important role in the design of radiometer used for observing typhoon. The NCEP (National Centres for Environmental Prediction) oper...The key factors of temporal and spatial resolution for typhoon observation played an important role in the design of radiometer used for observing typhoon. The NCEP (National Centres for Environmental Prediction) operational global analysis data prepared operationally every six hours were used as the initial field for mesoscale weather research and forecasting model (WRF) and drove the model to output atmospheric parameters such as hydrometeor content, temperature and humidity profiles at different time, which were inputs for the Atmospheric Radiative Transfer Simulator (ARTS) to calculate brightness temperature observed from geostationary earth orbit at oxygen absorption and water absorption band. The atmospheric humidity and temperature profiles of typhoon domain were retrieved from geostationary sub-millimetre atmospheric sounder. The results show that the profile retrievals using BP-NN algorithm have a best agreement with those from radiosonde, which is less than 20% and 1 K of root mean square error, respectively. For precipitation rate retrievals, much better agreement with rain gauge and ECMWF datasets, the RMS is between 0.84 to 32.4 mm/h for sea surface 0.89 and 36.13 mm/h for land surface according to the classification by precipitation type.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 89 and 150 GHz channels operated in window are sensitive to precipitation and humidity. The 183 GHz humidity-sensitive channels and 118 GHz temperature-sensitive channels of the Microwave Humidity and Temperature ...The 89 and 150 GHz channels operated in window are sensitive to precipitation and humidity. The 183 GHz humidity-sensitive channels and 118 GHz temperature-sensitive channels of the Microwave Humidity and Temperature Sounder (MWHTS) on the Chinese Feng Yun 3C MWHTS (FY-3C MWHTS) polar-orbit meteorological satellite responds in part to precipitation. Combining 118 and 183 GHz channels, the paper develops a passive sub-millimeter atmospheric profile and precipitation retrievals algorithm for MWHTS onboard the FY-3C (Feng Yun-3C) satellite. The retrieval algorithm employs a number of back propagation neural network estimators trained and evaluated using the validated global reference physical model NCEP/WRF/ARTS and works for land and seawater with latitude between -40 to 40 degree. NCEP data per 6 hours were downloaded to run the Weather Research and Forecast model WRF, and to derive the typical precipitation data for the whole world. The Atmospheric Radiative Transfer Simulator ARTS is feasible for performing simulations of atmospheric radiative transfer. The results show that the profile retrievals using BP-NN algorithm has the best correlation with those from radiosonde, which is less than 18% and 1 K of root mean square error, respectively. For precipitation rate retrievals, a much better agreement is reached with rain gauge and ECMWF datasets, the RMS is between 0.80 to 30.24 mm/h for sea surface and 0.789 to 33.11 mm/h for land surface according to the classification by precipitation type. Also, the analysis of retrievals located in Tibetan plateau is provided as an example to justify the robustness and performance of retrieving 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
Atmospheric water vapor is an essential climate variable(ECV)with extensive spatial and temporal variations.Microwave humidity observations from meteorological satellites provide important information for climate syst...Atmospheric water vapor is an essential climate variable(ECV)with extensive spatial and temporal variations.Microwave humidity observations from meteorological satellites provide important information for climate system variables,including atmospheric water vapor and precipitable water,and assimilation in numerical weather prediction(NWP)and reanalysis.As one of the payloads onboard China’s second-generation polar-orbiting operational meteorological Fengyun-3(FY-3)satellites,the Microwave Humidity Sounder(MWHS)has been continuously observing the global humidity since 2008.The reprocessing of historical FY-3 MWHS data is documented in detail in this study.After calibrating and correcting the data,the quality of the reprocessed dataset is evaluated and the improvement is shown in this study.The results suggest that MWHS observations bias is reduced to approximately 0.8 K,compared with METOP-A Microwave Humidity Sounder(MHS).The temporal variability of MWHS is highly correlated with the instrument temperature.After reprocessing,the scene temperature dependency is mitigated for all 183 GHz channels,and the consistency and stability between FY-3A/B/C are also improved.展开更多
文摘The key factors of temporal and spatial resolution for typhoon observation played an important role in the design of radiometer used for observing typhoon. The NCEP (National Centres for Environmental Prediction) operational global analysis data prepared operationally every six hours were used as the initial field for mesoscale weather research and forecasting model (WRF) and drove the model to output atmospheric parameters such as hydrometeor content, temperature and humidity profiles at different time, which were inputs for the Atmospheric Radiative Transfer Simulator (ARTS) to calculate brightness temperature observed from geostationary earth orbit at oxygen absorption and water absorption band. The atmospheric humidity and temperature profiles of typhoon domain were retrieved from geostationary sub-millimetre atmospheric sounder. The results show that the profile retrievals using BP-NN algorithm have a best agreement with those from radiosonde, which is less than 20% and 1 K of root mean square error, respectively. For precipitation rate retrievals, much better agreement with rain gauge and ECMWF datasets, the RMS is between 0.84 to 32.4 mm/h for sea surface 0.89 and 36.13 mm/h for land surface according to the classification by precipitation type.
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 89 and 150 GHz channels operated in window are sensitive to precipitation and humidity. The 183 GHz humidity-sensitive channels and 118 GHz temperature-sensitive channels of the Microwave Humidity and Temperature Sounder (MWHTS) on the Chinese Feng Yun 3C MWHTS (FY-3C MWHTS) polar-orbit meteorological satellite responds in part to precipitation. Combining 118 and 183 GHz channels, the paper develops a passive sub-millimeter atmospheric profile and precipitation retrievals algorithm for MWHTS onboard the FY-3C (Feng Yun-3C) satellite. The retrieval algorithm employs a number of back propagation neural network estimators trained and evaluated using the validated global reference physical model NCEP/WRF/ARTS and works for land and seawater with latitude between -40 to 40 degree. NCEP data per 6 hours were downloaded to run the Weather Research and Forecast model WRF, and to derive the typical precipitation data for the whole world. The Atmospheric Radiative Transfer Simulator ARTS is feasible for performing simulations of atmospheric radiative transfer. The results show that the profile retrievals using BP-NN algorithm has the best correlation with those from radiosonde, which is less than 18% and 1 K of root mean square error, respectively. For precipitation rate retrievals, a much better agreement is reached with rain gauge and ECMWF datasets, the RMS is between 0.80 to 30.24 mm/h for sea surface and 0.789 to 33.11 mm/h for land surface according to the classification by precipitation type. Also, the analysis of retrievals located in Tibetan plateau is provided as an example to justify the robustness and performance of retrieving 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.
基金Supported by the National Key Research and Development Program of China(2018YFB0504900 and 2018YFB0504902)National Natural Science Foundation of China(41775020,42005105,and 41905034)。
文摘Atmospheric water vapor is an essential climate variable(ECV)with extensive spatial and temporal variations.Microwave humidity observations from meteorological satellites provide important information for climate system variables,including atmospheric water vapor and precipitable water,and assimilation in numerical weather prediction(NWP)and reanalysis.As one of the payloads onboard China’s second-generation polar-orbiting operational meteorological Fengyun-3(FY-3)satellites,the Microwave Humidity Sounder(MWHS)has been continuously observing the global humidity since 2008.The reprocessing of historical FY-3 MWHS data is documented in detail in this study.After calibrating and correcting the data,the quality of the reprocessed dataset is evaluated and the improvement is shown in this study.The results suggest that MWHS observations bias is reduced to approximately 0.8 K,compared with METOP-A Microwave Humidity Sounder(MHS).The temporal variability of MWHS is highly correlated with the instrument temperature.After reprocessing,the scene temperature dependency is mitigated for all 183 GHz channels,and the consistency and stability between FY-3A/B/C are also improved.
