NCEP data assimilation systems status and plans

1. NCEP data assimilation systems status and plans John C. Derber Environmental Modeling Center NCEP/NWS/NOAA With input from: Many others

2. Data Assimilation • At EMC we do not have resources to develop and maintain Global, Regional, Mesoscale, RTMA, AQ, Analysis of Record systems of different structures and characteristics • Unified system – GSI – GSI/ENKF hybrid • Enhancements meant for one application of the system should be applicable for other systems and should benefit other applications. • Must be certain uniformity across systems.

3. Data assimilation group collaborators • GMAO • Global – 4dVar – Constituent and Aerosol assimilation • DTC • Regional/Mesoscale – Support Universities and other users • ESRL • Regional – Rapid Refresh • Hybrid system • NCAR/AFWA • Regional – Operational – ARW • NESDIS • JCSDA • Others welcome

4. Collaborative development Established Code management system Numerous meetings with development groups Code management and oversight group beginning through DTC

5. Future Directions • Hybrid Assimilation - EnKF/variational • 4d-Var • Improved cloud/precipitation analysis • Inclusion of cloudy radiances • Additional observations • Improved balance • Improved use of current data • Storm relocation

6. Hybrid EnKF/GSI assimilation • Part of background error covariance defined by ensembles • Situation dependent background error • Improved balance between variables (includes all variables including ozone and moisture) • Testing beginning for global system (Whitaker based), but computational resources limited • Mingjing working on hurricane system • For regional/hurricane system use global ensembles? Being tested – substantial cost savings • Inter-variable interactions may not always be good (e.g., influence of ozone observations on wind field) • Need to run ensembles and high resolution system whenever changes to either system or the hybrid analysis • Further development work may be necessary to properly handle model bias

7. Improved Cloud/precipitation analysis • CRTM cloud and precipitation capable • Including cloud/precipitation physics in analysis system • Beginning work to include cloudy microwave radiances in analysis • IR radiances being included through partners • Inter-variable covariances will be handled by ensemble covariances • Implications for bias correction and quality control

8. Additional observations • Preparing for use of NPP/JPSS and GOES-R instruments • Working on including more IASI and AIRS moisture channels • Attempting to include SSM/IS F16-18. • Testing AMSRE data • Improving quality control for AMSU-A, AMSU-B and MHS resulting in use of more data • Adding additional GPS-RO platforms • Working on inclusion of SEVIRI radiances • Inclusion of aircraft based doppler wind estimates

9. Improved Balance • Pursuing multiple paths to improve balance in initial state • Post-processing (after relocation and/or after analysis) • Inclusion of improved balance within analysis • Inclusion of TLNMI in regional system • Balance through Hybrid assimilation system

10. Improved use of current observations • Upgrading CRTM – surface emissivity, non-LTE, etc. • Including additional effects in Radiative transfer calculations, FOV size and shape, Clouds, trace gases, aerosols, etc. • Pursuing more accurate observational data base dictionary • Creating revised observational data base to allow improved quality control based on recent history. • Use of GPS-RO bending angles rather than refractivities

11. Hurricane Data Assimilation • Inclusion of aircraft Doppler winds • Develop storm relocation code (w/ MIT) to improve relocation of hurricane. External to analysis code and requiring separate balancing code. • Include diabatic effects into GSI Balance and further enhancements to balance equation • Develop capability to incorporate microwave cloudy radiances • Develop Hurricane hybrid ensemble/GSI capability • Incorporate storm relocation code within GSI (to allow direct use of balance code and account for background error properly)

12. Challenges • Collaborations • Collaborations allow more straightforward inclusion of new developments • Must ensure that collaborations don’t slow us down • Code management becomes much more difficult • External groups must conform to Collaboration requirements. • Multiple funding agencies, multiple bosses, different goals • Data • Processing of new data still slow and difficult because many new formats • Data handling system and quality control • Assimilation of clouds and precipitation • Use of satellite radiances in regional systems (bias correction) • Computational resources • Slow implementation process

13. Global Implementation Q1FY10 • Major components • Inclusion of NOAA-19 AMSU-A/B, HIRS • Inclusion of RARS 1b data • Inclusion of NOAA-18 SBUV/2 and OMI • Assimilate EUMETSAT-9 wind vectors • Use of Hurricane central pressure estimate • Improved use of GPS RO observations • Include Dry mass constraint • Inclusion of 2 additional GPS RO satellites in Q2FY10

14. Prepare for FY11 implementations • All implementations should be snapshots on trunk • short branches created when problem found • Many enhancements completed (extracted from trac pages) • Improved OMI QC • Removal of redundant SBUV/2 total ozone • Retune SBUV/2 ozone ob errors • Relax AMSU-A Channel 5 QC • New version of CRTM 2.0.2 • Inclusion of Field of View Size/Shape/Power for Radiative transfer • Remove down weighting of collocated radiances • Limit moisture to be >= 1.e-10 in each outer iteration and at end of analysis • Include ASCAT winds • Improve location of Buoys in vertical (move from 20 to 10m) • Improved GSI code with optimization and additional options

15. Prepare for FY11 implementations • Many enhancements completed (cont.) • Add Radar and Lightning data IO and cloud analysis for RR • GSI Bundle to generalize code/analysis variables • Hybrid use of ensembles for global (regional soon) system (Dual resolution) • Add analysis tools to repository • Upgrade background error covariance files • Upgrade quality control of MHS/AMSU-B water vapor channels • Add reading of Aerosol data • Regression tests for code

16. Prepare for FY11 implementations • Additional Enhancements underway (extracted from trac) • 4D-Var system using perturbation model • Common Makefile for multiple platforms • Add more tools into repository • Update assimilation of TMI rainrate using improved convection parameterization • Inclusion of moist physics in TLNMI • Include noise reduction in processing of SSM/IS data • Include F16-F18 SSM/IS data in GSI analysis • Updated radiance bias correction (preconditioning, updating channels not used and incorporate angle dependent part inside GSI) • Include external estimates of trace gases in CRTM

17. Prepare for FY11 implementations • Additional Enhancements underway (Cont.) • Inclusion of addition (higher peaking) IASI/AIRS moisture channels • Inclusion of AMSRE data • New localization options for hybrid EnKF/GSI • Use of sensitivity tool • SST analysis within GSI • GPS RO bending angle and use of compressibility factors • Regional strong constraint • Inclusion of aerosols in CRTM • General code clean-up and optimization