1. Experimental El Niño/Southern Oscillation Predictions by the UCLA Atmospheric General Circulation Model (GCM) Coupled to the MIT and POP Oceanic GCMs using the Earth System Model Framework (ESMF) C. R. Mechoso (1), Gabriel Cazes-Boezio (1, 3), J. A. Spahr (1), D. Menemenlis (2), and S.J. Zhou (4) (1) Dept. Atmospheric and Oceanic Sciences, UCLA, USA (2) NASA/Caltech Jet Propulsion Laboratory, USA (3) On leave from IMFIA, Universidad de la Republica, Uruguay (4) Software Integration and Visualization Office, NASA/GSFC and Northrop Grumman This talk presents the first independent adoption of ESMF technology.

2. Model components: UCLA Atmospheric GCM LANL Parallel Ocean Program (POP) UCLA ACTM (which can include up to 64 species) Simple NASA/JPL Ocean Chemical Transport Model Distributed Data Broker UCLA Earth System Model Atmospheric General Circulation Model (AGCM) Data Broker Oceanic General Circulation Model (OGCM) Atmospheric Chemical Tracer Model (ACTM) Oceanic Chemical Tracer Model (OCTM)

3. Increasing the Interoperability of an Earth System Model: Atmospheric-Ocean Dynamics and Tracer Transports NCC4-624 C. R. Mechoso, PI Major thrusts of the project: to further our understanding of an ability to predict the dynamic interaction of physical and chemical processes affecting Earth to incorporate the use of NASA data and highlight its importance to demonstrate interoperability of codes used in the community of Earth Science.

4. UCLA AGCM - MIT OGCM

6. UCLA AGCM - LANL POP

8. Model components: UCLA AGCM with upgraded PBL parameterization LANL Parallel Ocean Program (POP) and MIT OGCM, both in a quasi-global domain with the same grid. UCLA ACTM (which can include up to 64 species) Simple NASA/JPL Ocean Chemical Transport Model UCLA Earth System Model Atmospheric General Circulation Model (AGCM) Data Broker Oceanic General Circulation Model (OGCM) Atmospheric Chemical Tracer Model (ACTM) Oceanic Chemical Tracer Model (OCTM) ESMF

9. Porting Strategy 1)Model codes (AGCM, OGCM) were restructured to isolate Initialize, Run and Finalize tasks (i.e., were made ESMF compliant) 2)An ESM Driver Program (EDP) was created to control the sequence in which those Initialize-Run-Finalize tasks and data transfers are executed, as well as to keep track of simulation time.

10. Coupled Atmosphere-Ocean Application in ESMF- Superstructure Initialize Run Finalize Initialize Run Finalize UCLA AGCM MIT OGCM POP OGCM Import/Export States Atmos to Ocean Coupler Ocean to Atmos Coupler AGCM AppOGCM App ESM Application Infrastructure

11. The difference in prediction between with and without ESMF is possibly due to the different regridding methods --- to be verified!

12. Generic Coupler in ESMF Observation: couplers for UCLA AGCM/LANL OGCM and for UCLA AGCM/MIT OGCM are almost identical

13. Issues in Coupling Model Components (e.g., From Ocean to Atmosphere) Atmo Init1_a(…) Init2_a(…) Run_a(…) Final_a(…) ssta ua va Ocean Init1_o(…) Init2_o(…) Init3_o(…) Run_o(…) Final_o(…) Sst_o S_o U_o V_o Sea_o F_o 1. Function names in model components are different:  ESMF’s solution:  Uses three standard functions with a stage option, initialize, run, and finalize  Use a function registration service, setEntryPoint and setService 2.The names of import variables of a “use” component are different from those of export variables of a “provide” component. 3.The number of import variables of a “use” component are different from that of export variables of a “provide” component. exportimportexportimport Coupler Regrid(…)

14. Generic Coupler: design (automatically name mapping and regridding) T_surf S_surf U_surf V_surf Sea_level frazil Sst_o S_o U_o V_o Sea_o F_o T_surf U_surf V_surf ssta ua va Ocean Atmos Atmo Ssta Ua Va Ptr_Sst_o Ptr_S_o Ptr_U_o Ptr_V_o Ptr_Sea_o Ptr_F_o Ptr_Ssta Ptr_ua Ptr_va ssta ua va Sst_o U_o V_o Destination field Match name regrid remake export state needed source field Ptr_Sst_o Ptr_U_o Ptr_V_o Ptr_Ssta Ptr_ua Ptr_va Output import state register For the case of only interpolation operation is needed. CFnamepointer

15. SUMMARY The coupled atmosphere-ocean model shows skill in ENSO prediction from six months in advance. The skill is higher for the UCLA AGCM/MIT OGCM combination. The UCLA AGCM was coupled to the MIT OGCM and LANL POP using ESMF services. The most time demanding task was to make the model components ESM compliant. Much more work with the ESMF is needed for debugging, increased capability and user friendliness. Model codes integrated into the ESMF require maintenance if the framework is to become a standard for Earth System Modeling.

16. Project Organization Tier I: Upgrade the UCLA Earth System Model (ESM). The principal upgrades are in the planetary boundary layer (PBL) parameterization of the AGCM and domain extension of the OGCM. Perform ENSO predictions. Tier II: Address issues of code interoperability by using the ESMF services to couple the UCLA AGCM with either LANL POP or the MIT OGCM and by performing forecasts of El Niño/Southern Oscillation (ENSO). Tier III: Assess the impact of NASA data by comparing ENSO forecasts using initial states provided by JPL’s ECCO project (http://ecco.jpl.nasa.gov). The MIT OGCM is a component in the ECCO’s data assimilation system, while POP is not.

17. Module AGCM_GridComp AGCM_Initialize AGCM_Run(start time, end time) AGCM_Finalize The AGCM as ESMF Compliant

18. Call gridded components to perform finalize functions Call gridded components drivers (time advance) Call coupler components for regridding and transfers Register components Create data bases Initialize components ESM Application

19. Clean up and close communications Retrieve SST from import state Create ESMF grid Create fields and attach them to import/export states Read control files Set up node distribution Component Driver in EDP (e. g., AGCM) Advance in time Strore updated fields in export state

20. Modeling Focus: PBL in UCLA AGCM Traditional Framework Suarez et al. (1983) Revised Framework Konor and Arakawa (2005)

21. AGCM Exec E OGCM Exec CPL Ctrl CPL Ctrl AGCM Coupler OGCM Data Fields Data Fields I I E Time executionTime execution I E Import State Export State Data Reference Data Flow

22. “Double ITCZ” Problem Hypothesis 1: Poor heat transport by ocean eddied from upwelling regions - Insufficient OGCM resolution? Hypothesis 2: Poor simulation of the zonal circulation - Difficulties in the simulation of resolved and subgrid processes? Annual Mean SST Model Observation UCLA AGCM - MIT OGCM

23. ESMF Class Structure MachineModel Layout DistGrid PhysGrid State Bundle Gridded Component Array Utilities: TimeMgr, Config, LogErr, I/O etc. F90 Superstructure Infrastructure Field Grid Regrid Comm Data Communications Route Coupler Component C++ Application Component

24. ESMF Component Registration Components provide a single externally visible entry point, which register the other entry points with the ESMF. Components can: -Register one or more Initialization, Run, Finalize, and Checkpoint entry points. -Register a private data block which can contain all data associated with this instantiation of the Component. Higher level Comp cmp_register() cmp_run() cmp_final() cmp_init() ESMF Framework Services Public subroutine Private subroutine

25. Coupler Components Import/Export States The AGCM does not have access to the internals of the OGCM, and vice versa. The exchange data is through a coupler component, which exchanges the roles of Export State from one component to Import State for the other component. The coupler components also do the grid transformations. coupler ocn_component subroutine ocn_run(comp, & ImportState,ExportState, Clock, rc) atm_component subroutine atm_run(comp, & ImportState,ExportState, Clock, rc)