1. 1 ESMF @ NCEP Mark Iredell Chief NCEP/EMC Global Climate and Weather Modeling Branch May 23, 2006 NCEP: “where America’s climate, weather, and ocean services begin”

2. 2 Outline Motivation Vision Progress Issues Conclusion

3. 3 Motivation

4. 4 Why ESMF @ NCEP? Most of the improvement in weather forecast skill over the past 20 years is due to improving numerical forecast system technology. However, national investment in computing and model development in the geophysical sciences is limited and dispersed. Therefore, it behooves us to leverage this investment with a common modeling framework and shared software development.

5. 5 Impact of Observations and Numerical Forecast System Technology Growth on Global Forecasts Obs only NFS Tech Growth + Obs NFS Tech Growth: Computing Data Assim. Models Ensembles

6. 6 Why ESMF @ NCEP? Most of the improvement in weather forecast skill over the past 20 years is due to improving numerical forecast system technology. However, national investment in computing and model development in the geophysical sciences is limited and dispersed. Therefore, it behooves us to leverage this investment with a common modeling framework and shared software development.

7. 7 Vision* *my vision anyway, not necessarily everyone’s

8. 8 ESMF Component Framework Application Change Resolution Surface Cycling Atmosphere ATM Dynamics ATM Physics Post Vertical Post Product Generator Output GRIB/BUFR some other coupler some other component

9. 9 NCEP component list (incomplete*) I/O components ATM gridded component GFS physics component NAM physics component GMAO physics component GFS dynamics component UMO dynamics component Finite volume dynamics component Post component Surface cycling component Coupler components Land component Ocean component Ice component Aerosol component Ionosphere component Mesoscale component Hurricane components GSI 3DVAR component Radiative Transfer component Change resolution coupler component Dynamics/Physics coupler component Ensemble coupler component Atmosphere/Land coupler component Atmosphere/Ice/Ocean coupler component Atmosphere/Aerosol coupler component Atmosphere/Ionosphere coupler component Analysis/Model coupler component Model/Post coupler component Other couplers *only includes components with active ESMF plans

10. 10 Progress

11. 11 Progress with ESMF @ NCEP The NCEP global forecast system (GFS) with a fully compliant ESMF adoption should be implemented operationally in June 2006. (Yang, Moorthi, Young) Features –Stand-alone gridded component –Uses clock, config, logerr –No effect on results or timings

12. 12 Progress with ESMF @ NCEP The GFS already runs successfully in ensemble mode (14 members run concurrently). A stochastic ensemble coupler is being developed. (Yang, Hou) Promising progress toward making GFS a gridded rather than spectral component. (Juang) The B-grid global model (UMO) is near to being ready as a gridded component. (Black) Several other collaborations already support ESMF gridded components.

13. 13 Issues

14. 14 Costs/Benefits of ESMF @ NCEP + Community involvement and lovefests + Common framework for collaboration + Shared software burden - Significant conversion effort - Increased code complexity - More black boxes

15. 15 Costs/Benefits of ESMF @ NCEP Ultimately, the key resources for NCEP (and other institutions) are its working scientists. We must ensure that any framework decisions are the best for our people to continue to develop and maintain world-class geophysical models. ESMF allows each institution to find its comfort level in adopting the framework.

16. 16 Conclusion NCEP continues to participate as a partner in the EMSF experience