1. Metadata for the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) using the Earth System Modeling Framework (ESMF) Peter Bosler University of Michigan NCAR SIParCS Program August 4, 2009

2. Outline SIParCS Project – Sylvia Murphy, NCAR ESMF – Tim Campbell, Navy Research Lab. Stennis Space Center MS COAMPS Overview Why ESMF? – NUOPC – Metadata Project Results and Applications – Using COAMPS Metadata (internal & external)

3. SIParCS Project Describing Models – Add Metadata attributes to COAMPS Fields have Name, StdName, and Units attached Components have Model Name, Version, Coding Language, Web URL, etc.. attached Export metadata in XML format for each component Automating Models – ESMF already has coupling functions like parallel regridding – My job: Build an ESMF Attribute-based unit converter Use attributes to decide if conversion is necessary Perform the conversion using Unidata’s UDUnits Update the attributes to reflect conversion

4. COAMPS Basics “Coupled Ocean/Atmosphere Mesoscale Prediction System” Standard Navy model for “On-Demand” forecasting Regional weather prediction out to 72 hours (operational) High resolution, non-hydrostatic model

5. Motivation Earth System Modeling Framework – Chosen as Common Model Architecture and model-to-model interface standard by National Unified Operational Prediction Capability (NUOPC) – Facilitates modularity and flexibility by providing user-defined methods to couple independent components Metadata – Formally structured information with a controlled vocabulary embedded within the model itself, i.e., the ESMF Attribute class. – ESMF includes NUOPC recommended metadata capabilities – Metadata allows model components to be “self-describing”

6. Components – Gridded Components Atmosphere Component, Ocean Component, Wave Component Run on separate PETs in distributed environment – Coupler Components Handle communication between Grid. Comps. – COAMPS uses 5 ESMF Gridded Components States – Import/Export – Basic data structure for coupler communication Fields/Field Bundles – Data and Grid in one package – Field Bundles are collections of fields that share the same grid ESMF Terminology

7. ESMF Metadata ESMF “Attributes” implement standard ontologies such as the NetCDF Climate and Forecast Convention (CF) Attributes can be attached to most ESMF objects (i.e., Components, Field Bundles, Fields, etc.) Mechanism for fast search capability of both models and their datasets via online data portals (External Usage) Mechanism for component to component communication through an ESMF coupler (Internal Usage)

8. SIParCS Project (Part 1) Built ESMF & COAMPS on Bluefire – ESMF 4.0 beta snapshot 6 – COAMPS Version 4 Modified COAMPS code to include ESMF Attributes – Fields & States – Components (Atmosphere, Ocean, Wave, Ocean Bkgd, Wave Bkgd) – Linked Components to associated States and Fields Export COAMPS metadata XML

9. Sample XML Output

11. Internal Usage Example Coupler Ocean Export Atmos. Import During Initialize Phase, Coupler detects difference in attributes of the SST field between two components. Attributes of SST Export are degrees Celsius Attributes of SST import are degrees Kelvin

12. Internal Usage Example Coupler Ocean Export Atmos. Import Run Phase : Coupler receives Ocean SST data from Ocean Comp. in Celsius RunPhase: Export SST in °C RunPhase: Export SST in °C

13. Internal Usage Example Coupler Atmos. Import Ocean Export Run Phase: Coupler performs unit conversion to Kelvin using UDUnits and updates Field Attribute

14. Internal Usage Example Coupler Atmos. Import Ocean Export Run Phase: Coupler sends converted SST Field to Atmos. Comp. Atmos. Comp. receives SST field in °K

15. ESMF Superstructure ESMF Infrastructure COAMPS Atmos. Comp. Atmos. COAMPS Ocean Comp. Ocean Wave Watch 3 Wave Data Manipulation (Regridding, unit conversion, etc.) Data Transfer (Import/Export States, Fields & Field Bundles, and Metadata) SWAN

16. SIParCS Project (Part 2) Get to know UDUnits – UDUnits 2.1.8 – C library/API – XML database How to use UDUnits in ESMF? – Overlap with ESMF_Attributes – Error checking capability – Parallelization / numeric efficiency Write and test ESMF Physical Units module – In progress…

17. Summary ESMF is becoming the technical basis for operational numerical weather prediction COAMPS is an example of “modular modeling” using ESMF through component interoperability ESMF: – http://www.esmf.ucar.edu/ http://www.esmf.ucar.edu/ COAMPS: – http://www.nrlmry.navy.mil/coamps-web/web/home http://www.nrlmry.navy.mil/coamps-web/web/home UDUnits: – http://www.unidata.ucar.edu/software/udunits/ http://www.unidata.ucar.edu/software/udunits/