1. NOAA-CoRP Symposium, Aug 15-18, 2006 Radiative Transfer Modeling for Simulating GOES-R imagery Manajit Sengupta 1 Contributions from: Louie Grasso 1, Jack Dostalek 1, Dan Lindsey 2 and Mark DeMaria 2 1. CIRA/Colorado State University, 2. NOAA/NESDIS Fort Collins, CO

2. NOAA-CoRP Symposium, Aug 15-18, 2006 Methodology for simulating GOES-R imagery Mesoscale model output Inputs for radiative transfer Compute gaseous absorptionCompute cloud optical properties Compute GOES-R radiance or reflectance Forward Observational Operator

3. NOAA-CoRP Symposium, Aug 15-18, 2006 Mesoscale Model components for more accurate Radiative Transfer computations RAMS Numerical Cloud Model Non-hydrostatic cloud model developed at CSU Sophisticated two-moment cloud microphysics mass mixing ratio and number concentration are prognosed aggregates, graupel, hail, pristine ice, rain, snow, and cloud water Two-way interactive nested grids Four grids: 50 km, 10 km, 2 km (GOES-R) and 400 m (NPOESS). RAMS initial condition from NCEP ETA model analysis Run cloud model and use output as input to an observational operator to generate synthetic GOES-R satellite observations for different channels.

4. NOAA-CoRP Symposium, Aug 15-18, 2006 OPTRAN (part of JCSDA CRTM) used to calculate gaseous absorption GOES-R ABI coefficients obtained from JCSDA (3.9 – 13.3µm) Modified anomalous diffraction theory (MADT) for cloud optical properties assumes gamma distribution for the calculation of a mean diameter single scatter albedo, extinction coefficient, asymmetry factor for 7 hydrometeor types weighting by hydrometeor number concentration from RAMS for bulk optical properties Other possible methods for computing optical properties Mie theory for water drops Ice scattering tables from explicit computations. Observational Operator Highlights

5. NOAA-CoRP Symposium, Aug 15-18, 2006 Observational Operator Highlights Radiative transfer models Infrared Delta-Eddington scheme Visible and near-infrared Plane-parallel version of Spherical Harmonics Discrete Ordinate Method (SHDOMPP)

6. NOAA-CoRP Symposium, Aug 15-18, 2006 Case Studies May 8-9, 2003 :Severe thunderstorm outbreak over Oklahoma and Kansas. September 30-October 4, 2002: Hurricane Lili February 12-14, 2003: Lake effect snow

7. NOAA-CoRP Symposium, Aug 15-18, 2006 Synthetic 2 km GOES-R ABI Bands 7-16 8 May Severe Weather Case 3.9 µm 6.2 µm 7.0 µm 7.3 µm 8.5 µm 9.6 µm 10.35 µm 11.2 µm 12.3 µm 13.3 µm

8. NOAA-CoRP Symposium, Aug 15-18, 2006 Comparison of simulations from 3.9 µm with 10.35 µm of GOES-R ABI 3.9 µm 10.35 µm

9. NOAA-CoRP Symposium, Aug 15-18, 2006 Comparison of observations from Ch 3 (6.7 µm) of GOES-12 with Simulations ObservationsModeled May 8, 2003: thunderstorm outbreak

10. NOAA-CoRP Symposium, Aug 15-18, 2006 Comparison of observations from Ch 4 (10.7 µm) of GOES-12 with Simulations ObservationsModeled

11. NOAA-CoRP Symposium, Aug 15-18, 2006 Screened thunderstorm Brightness temperature <243 K observation model ObservationsModeled

12. NOAA-CoRP Symposium, Aug 15-18, 2006 Histograms of observed and modeled brightness temperatures ObservationsModel

13. NOAA-CoRP Symposium, Aug 15-18, 2006 Percentile scatter plot of 1 hour of observed versus modeled brightness temperatures Percentile Brightness temperature

14. NOAA-CoRP Symposium, Aug 15-18, 2006 Conclusions Mesoscale cloud model should contain 2 moment microphysics for cloud radiance/reflectance simulations. For simulation of all channels gaseous absorption coefficients should be available for OPTRAN. Optical properties for ice crystals and water droplets in clouds should be accurately computed. Radiative transfer modeling should be accurate but reasonably quick. Our current capabilities allow us to simulate different weather events.

15. NOAA-CoRP Symposium, Aug 15-18, 2006 Questions? Comments……….