| Launched by Japan in 2014,the new generation of geostationary meteorological satellite Himawari-8 in 2014 is equipped with an Advanced Himawari Imager(AHI)with high spatial and temporal resolution of visible,near-infrared and infrared channels.It provides possibility for analyzing or evaluating the variation characteristics of the water vapor content of different reanalysis datastes and the clouds simulated by numerical models.For evaluating the water vapor content of reanalysis datastes,this paper involves an Efficient Radiative Transfer Model(ERTM)to simulate the brightness temperatures(BTs)of European Centre for Medium-Range Weather Forecasts Re-Analysis-interim(ERA-interim)?European Centre for Medium-Range Weather Forecasts Re-Analysis-5(ERA5)and Modern-Era Retrospective analysis for Research and Applications,Version 2(MERRA-2)at multiple water vapor channels under the clear sky,and compares simulated BTs with AHI observations.Taking July 2016 as an example,it is found that ERA-interim underestimates the amount of water vapor above 280 h Pa,while overestimates that between 394 and 328 h Pa,but it performs well between 320 and 260 h Pa;ERA5 and MERRA-2 also significantly underestimate the water vapor content above 300 h Pa,but they are relatively accurate between 425 and 300 h Pa,and MERRA-2 is more accurate than ERA5.In addition,ERTM is also used to simulate the cloud top BTs of the weather research and forecasting model(WRF).The simulated BTs are compared with observed BTs at thermal infrared channels for assessing the cloud field structure simulated by WRF.The results show that WRF can accurately simulate the location of the cloud and the general cloud characteristics of Typhoon "Hato" and "Higos",but it tends to underestimate the coverage of typhoon area.Moreover,WRF overestimates the cloud optical thickness or cloud top height in typhoon area,while underestimates those features out of the typhoon region. |
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