Progress in Community Radiative Transfer Model for Satellite Radiance Assimilation Quanhua (Mark) Liu 1,2, Paul van Delst 1,3, Ming Chen 1, David Groff 1,3, Yong Chen 2, Andrew Collard 3, Sid-Ahmed Boukabara 1, Fuzhong Weng 4, John Derber 3 1 Joint Center for Satellite Data Assimilation; 2 ESSIC, University of Maryland, College Park, MD 3 NOAA/NCEP; 4 NOAA/NESDIS Center for Satellite Applications and Research; 1. Introduction The Community Radiative Transfer Model (CRTM), developed at the Joint Center for Satellite Data Assimilation, has been applied to the NOAA/NWS operational radiance assimilation in supporting of daily weather forecasting, to the NOAA Microwave Integrated Retrieval System for operational satellite products, and to international remote sensing community for remote sensing sensor calibration, air quality application, and others including projects at CICS/ESSIC. The latest CRTM version 2.1.3, which is applicable for passive microwave, infrared and visible sensors. It supports all NOAA satellite instruments, NASA MODIS, and many foreign meteorological satellites. 3. CRTM Modules and Supported Sensors 4. CRTM Transmittance Model 7.1 Stratosphere Sounding Unit(SSU) Forward model SfcOptics (Surface Emissivity Reflectivity Models) AerosolScatter (Aerosol Absorption Scattering Model) AtmAbsorption (Gaseous Absorption Model) CloudScatter (Cloud Absorption Scattering Model) RTSolution (RT Solver) Source Functions public interfaces CRTM Initialization CRTM Clearance Jacobian model Tangent-linear model Adjoint model Molecular scattering CRTM main modules The transmittance model is to compute atmospheric transmittance from absorbing gases In addition to ODAS model, a new transmittance model ODPS (Optical Depth in Pressure Space) has been implemented in version 2. Variable absorbing gases: H2O, CO2, O3, CO, N2O and CH4 4.1 Transmittance Model 7.3 SSMIS Radiance Assimilation for Hurricane Prediction CRTM 2.1 Release CRTM was initially proposed to support primarily the JCSDA partners to assimilate satellite radiance data into global/regional forecast systems It is now also supporting the US satellite program developments through generating a high quality proxy data for algorithm tests, developments and integrations It has been used in the NOAA/NESDIS microwave sounding product system It can be used to generate the synthetic satellite radiances from NWP nature runs for observation system simulation experiments (OSSE) It is linked to other key projects such as climate reanalysis and satellite cal/val Joint Center for Satellite Data Assimilation (JCSDA) Partner Organizations 2. CRTM CRTM simulated IASI, AIRS and CrIS spectrum SSU mission was started onboard TIROS-N in October 1978 ended onboard NOAA-14 in Using the CRTM, we removed the effects of atmospheric and cell CO 2 for a long-term data record of stratospheric temperatures. SSU showed that stratospheric temperatures may gradually recovered after Microwave sound unit (MSU) data supported the finding. Liu, Q., and F. Weng, 2009: Recent stratospheric temperature observed from satellite measurements, SOLA, 5, 53-56, doi: /sola Support more than 100 Sensors GOES-R ABI TIROS-N to NOAA-19 AVHRR TIROS-N to NOAA-19 HIRS GOES-8 to 14 Imager GOES-8 to 14 sounder Terra/Aqua MODIS METEOSAT-SG1 SEVIRI Aqua AIRS, AMSR-E, AMSU-A, HSB NOAA-15 to 19 AMSU-A NOAA-15 to 17 AMSU-B NOAA-18, 19 MHS TIROS-N to NOAA-14 MSU, DMSP F13 to 15 SSM/I DMSP F13,15 SSM/T1 DMSP F14,15 SSM/T2 DMSP F16-20 SSMIS Coriolis Windsat TiROS to NOAA-14 SSU METOP-A IASI AMSUA, MHS, HIRS, AVHRR FY-3 IRAS, MWTS, MWHS, MWRI SNPP CrIS/ATMS/VIIRS AMSR2, AMSR-E, TMI others 4.2 Specific Transmittance Model Zeeman-splitting effect into account for affected microwave channels Stratospheric sounder unit transmittance for accounting for onboard CO2 cell pressure leaking. NLTE Model 5. Aerosol and Cloud Models Aerosols: Global Model, GOCART Dust, Sea Salt, Organic carbon, Black carbon, Sulfate Regional Model CMAQ is under implementation. Aerosol are assumed to be spherical particles. Spheroid shape for dust is under consideration. Clouds: Liquid, Rain, Snow, Ice, Graupel, and Hail Non-spherical particles for ice cloud are used for Visible and IR bands. Effect of non-spherical particles. Ding, et al. TAMU 6. Surface Emissivity and Reflectance The surface is divided as Water, Land, Ice, and Snow. CRTM computes emissivity and reflectance internally. CRTM accepts user defined emissivity data. CRTM uses Ocean BRDF IR model. Other BRDF is under development. 7. Applications 7.2 Monitoring Sensor Performance Using the CRTM simulation, we identified that VIIRS M12 image striping over oceans at daytime was caused by the difference among 16 detectors. Liu, Q., C. Cao, and F. Weng, 2013: Striping in the Suomi NPP VIIRS Thermal Bands through Anisotropic Surface Reflection, J. Atmos. Oceanic. Technol., 30, 2478–2487. doi: D D Strong absorption above 20 hPa for NOAA-16 because of out-of-band. The SSMIS measures radiances in 24 channels covering a wide range of frequencies (19 – 183 GHz) conical scan geometry at an earth incidence angle of 53 degrees maintains uniform spatial resolution, across the entire swath of 1700 km. Satellite information contents: SSMIS brightness temperature varies as Hurricane developed and degraded. Liu and Weng, 2006: GRL,V33, L06817 Impact studies. Control the operational result; Test using SSMIS radiance assimilations. Liu and Weng, 2006: GRL, V33, L CRTM release is available from ftp.emc.ncep.noaa.govftp.emc.ncep.noaa.gov at jcsda/CRTM/REL Using the CRTM IR BRDF model, simulations over oceans agree with measurements. SSU Zeeman effect: The O 2 transition line is split into many sublines, which can change transmittance. 5 hPa 15 hPa