CCSM ESMF Implementation and Evaluation Project

Name: Stage 1 ESMF Evaluation for CCSM

Mission Statement:

To perform a Stage 1 evaluation of the use of ESMF in CCSM and provide an assessment of the accompanying risks and advantages. If Stage 1 evaluation is accepted, then Stage 2 evaluation will be performed.

Goals:

To assess the long-term suitability of using ESMF in CCSM production model codes and have CCSM make a commitment (yes/no/conditional) on whether ESMF will be formally adopted in future code releases. We will create an evaluation prototype code based on stand-alone CAM. CAM and each CAM surface model will be treated as ESMF gridded components. ESMF couplers will be utilized to to exchange surface data between CAM and each of its surface components. This projects will include the following:

• Creation of quantitative acceptance metrics
• Creation of qualitative survey metrics
• Creation of code based off of stand-alone CAM that uses ESMF to couple between CAM and the CAM surface models CLM, CAM-CSIM, and CAM-DOCN as ESMF-components.
• Distribution of this code and version without ESMF to CAM collaborator's
• Validation of quantitative and qualitative metrics on the evaluation code.

On-Line Project Reports

• Stage-1 Release Schedule
• CCSMF ESMF Project Page

Motivation:

The decision to evaluate ESMF based on stand-alone CAM is due largely to the fact that CAM is already a sequential SPMD model, thereby making the validation of ESMF much more straightforward. Both numerical integrity as well as performance metrics can easily be monitored as CAM is migrated to a system where CAM and CAM surface components become ESMF gridded components. Furthermore, the stand-alone configuration of CAM has a much larger external collaborator base than CCSM3. Distributing the ESMF version of stand-alone CAM to this community will result in a much more thorough as well as expedient validation of ESMF than starting from the full CCSM3 model system.

Authority:

Bill Collins

Project Lead:

Mariana Vertenstein

Scientific Lead:

None

Resources:

• Brian Eaton -- Project review
• Brian Kauffman -- Project design and review
• Erik Kluzek -- CAM programming
• Mariana Vertenstein -- Project lead and CLM programming
• CSEG, CCSM scientists and CCSM/CAM community