Basis of GV for Japans Hydro-Meteorological Process Modelling Research GPM Workshop Sep. 27 to 30, Taipei, Taiwan Toshio Koike, Tobias Graf, Mirza Cyrus Raza, Thomas Pfaff, University of Tokyo and JAXA 2 Overview Remote Sensing of Solid Precipitation Ground Based Radiometer Observation of Snowfall over the Ocean Cloud Microphysics Data Assimilation System Cloud Microphysics Data Assimilation System GV Needs GV Needs 3 Methodology Physical Based Retrieval of Snowfall: Minimizing the difference between modeled and observed brightness temperature data.Minimizing the difference between modeled and observed brightness temperature data. Consider all parameters effecting radiative transfer.Consider all parameters effecting radiative transfer. 4 Model Parameterisation Many parameters need to be considered in RTM, which can be derived from additional data sources: Humidity, Pressure,Temperature: Observation, NWP Model Output/AIRSHumidity, Pressure,Temperature: Observation, NWP Model Output/AIRS Cloud Position: Satellite Observation in Infra-red Region, CeilometerCloud Position: Satellite Observation in Infra-red Region, Ceilometer Boundary Condition:Boundary Condition: Ocean => Wind SpeedOcean => Wind Speed SpaceSpaceMissing: SnowfallSnowfall Cloud WaterCloud Water 5 Snow Water Path/Cloud Water TB observation is only integrated view of all parameters can't get Profile of Snowfall and Cloud Water can't get Profile of Snowfall and Cloud Water assume uniform profile (integrated snowfall) assume uniform profile (integrated snowfall) Model Parameterisation Reality Model 6 Wakasa Bay 2003 Application: AMSR/AMSR-E Validation Project AMSR/AMSR-E Validation ProjectData: Humidity, Temperature & Pressure => Global Reanalysis (GANAL) Data, Radio SondeHumidity, Temperature & Pressure => Global Reanalysis (GANAL) Data, Radio Sonde Cloud Top => MODIS Product, GMSCloud Top => MODIS Product, GMS Wind Speed => AMSR-E ProductWind Speed => AMSR-E Product Brightness Temperature => AMSR-E, Ground Based RadiometerBrightness Temperature => AMSR-E, Ground Based Radiometer Comparison with Radar Observation and Gauge Data Ground-Based Radiometer Snowfall Observation 8 Radiative Transfer Simulations Lookup Table Ground Based Observation Snowfall Rate Cloud Liquid Water Relative Humidity, Temperature and Pressure Profile Cloud Top and Bottom Passive Microwave Brightness Temp. at 36.5 and 50.8 GHz Radar Observation liquid solidSnowfall Profiles => Radar Observation liquid solid Precise (spatial) Information about cloud coverPrecise (spatial) Information about cloud cover 25 Basic Concept Satellite only provides observation during overpass => Continuous Representation of Precipitation => Data Assimilation Satellite only provides observation during overpass => Continuous Representation of Precipitation => Data Assimilation Data Assimilation of Cloud Water and Water Vapor => (Solid) Precipitation in Future 26 Assimilation Window ARPS Model Simulation 16:30z 16:30z 17:10z Assimilation Window: 40 mins TB obs AMSR-E Initial Guess 29 th Jan th Jan 2003