April 2008 Christopher M. Hill Patrick J. Fitzpatrick Valentine G. Anantharaj Mississippi State University Lars-Peter Riishojgaard Global Modeling and Assimilation Office / NASA Joint Center for Satellite Data Assimilation An Observing System Simulation Experiment to Evaluate ATMS and CrIS Observations

General Overview component sensors of NPOESS and NPP to include:component sensors of NPOESS and NPP to include: –Advanced Technology Microwave Sounder ( ATMS ) across track scanning microwave radiometer cross-track resolution: 1.5 km –Cross-track Infrared Sounder ( CrIS ) Fourier transform spectrometer cross-track resolution: 14.0 km vertical resolution: ~ 3.0 km Combination of ATMS / CrIS should improve profiles of T and q Mesoscale OSSE needed to assess the impact of ATMS / CrIS 2

3 MSU OSSE plan mesoscale nature run (MSNR) using “global” WRFmesoscale nature run (MSNR) using “global” WRF –nested (one-way), initialized with ECMWF T511 NR data sensitivity experiments using second model (MM5?)sensitivity experiments using second model (MM5?) –cold start simulation –assimilate synthetic surface, rawinsonde observations –assimilate data representing ATMS / CrIS –initial analyses tuned to model background errors –use second model to avoid similarity in model error (fraternal twin problem) investigate significant mesoscale weather events with preferred focus at the U.S. coast of the Gulf of Mexicoinvestigate significant mesoscale weather events with preferred focus at the U.S. coast of the Gulf of Mexico –identified several case events through review of ECMWF NR output

4 Case events identified from ECMWF T799 NR May 2-4: squall line affecting all points along US Gulf coast May 7-8: decaying squall line over TXOct 10-11: squall line / tropical wave MSLP (hPa)3-h convective precipitation (mm) MSLP (hPa)3-h convective precipitation (mm).

5 Case events from full resolution ECMWF T799 NR May 2-4: squall line affecting all points along US Gulf coast May 7-8: decaying squall line over TXOct 10-11: squall line / tropical wave MSLP (hPa)3-h convective precipitation (mm) MSLP (hPa)3-h convective precipitation (mm).

Mesoscale NR WRF v3.0 global grid Global grid Initialized with ECMWF T511 NR dataInitialized with ECMWF T511 NR data ∆x ~ 40 km∆x ~ 40 km New WRF global domain capabilityNew WRF global domain capability –all synthetic data to be assimilated –no boundary condition issue Integration periods surrounding case events:Integration periods surrounding case events: –27 September - 11 October –23 April - 08 May (2 case events) Regional nested grid broad domain centered over Gulfbroad domain centered over Gulf ∆x ~ 14 km ( CrIS resolution )∆x ~ 14 km ( CrIS resolution ) integration periods:integration periods: case event duration ( h) Images adopted from Shuttle Radar Topography Mission WRF regional grid 6

Sensitivty tests with second model Image adopted from Shuttle Radar Topography Mission mesoscale model grid 135°W 45°W 60°N 0°0°0°0° Runs performed with MM5 (?)Runs performed with MM5 (?) MSNR as initial conditionsMSNR as initial conditions ∆x ~ 14 km (+ nested grid?)∆x ~ 14 km (+ nested grid?) domain focused on Gulfdomain focused on Gulf integration periods:integration periods: duration of case events ( h) compare against MSNR and against ECMWF HRNRcompare against MSNR and against ECMWF HRNR Houston / Galveston North Central Gulf Coast Tampa Bay region 7

8 Status of MSU OSSE Progress to dateProgress to date –HRNR data ready for OSSE –HRNR assessment yields cases Requirements for OSSERequirements for OSSE –synthetic observations –simulated ATMS / CrIS data –generate synthetic data with CRTM? Next step is to conduct MSNRNext step is to conduct MSNR (ATMS / CrIS) MM5/WRF MSNR