Adding Metadata to the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) Using the Earth System Modeling Framework

Participants

Peter Bosler/University of Michigan, Sylvia Murphy/ESMF Core Team

For questions on this project, please contact curator@list.woc.noaa.gov.

Motivation

One of the goals of the Curator Project is to facilitate automatic processing between models. One of processes that Curator seeks to affect is model coupling. Coupling involves the transfer of a data from one model to another. Since models are often self-contained units, this data (called an import or export state) needs to be transformed into a structure that is acceptable by the receiving model. Having a model self-describe its current and required grids and units is the first step to the potential automation of this process. Automation of coupling model will in turn increase the modularity and resuse of components within a modeling system.

These objectives have been recognized by the National Unified Operational Prediction Capability (NUOPC), a consortium of U.S. operational centers. NUPOC has chosen the Earth System Modeling Framework as its common modeling architecture for both future model development and for the modification of legacy applications. NUOPC has also specified the incorporation of metadata into climate and weather prediction models as an important goal.

Approach

COAMPS

COAMPS is a high resolution regional weather model used operationally by the Navy on a daily basis. It is the go-to model for forecasting in mesoscale maritime environments out to 72 hours. In can run be run in-situ aboard ship, as well as by operational centers. In its research capacity, it has been used to study all sorts of mesoscale dynamics, from orographic flow to tropical cyclones.

COAMPS by its very nature is a coupled system and a long term goal of the system is the modularity of the ocean component.

Results

A developmental version of COAMPS was transfered to NCAR and modified to run on NCAR's IBM SP system Bluefire. All internal field as well as import and export state variables were modified to include variable names and units utilizing ESMF's attribute capabilities. The model was then run, and an XML file with the metadata was produced. This file served as verification that the metadata was coded correctly.

The next phase of the project investigated Unidata's UDUNITS software as a possible unit conversion option. Unit conversion is necessary to complete the automation process. It was discovered however, that this software is primarily designed to check for the consistency of units and not to actually convert units. This is a feature and not a bug in the software. UDUNITS specifically avoids unit conversions because variables that are non-linear in nature should not be converted by a simple constant. The search for a reasonable unit conversion software library will be necessary to complete this project.

Attribution

This project would not have been possible without the assistance of Tim Campbell of the Naval Research Laboratory. Tim is the lead COAMPS developer and provided the project with much needed guidance.

References

• Bosler, P., (2009), Metadata for the Coupled Ocean/Atmosphere Prediction System Using the Earth System Modeling Framework. (Download PowerPoint file)