ESMF/OpenMI Coupling for Hydrological Applications
Participants
Kathy Saint/ESMF Core Team, Sylvia Murphy/ESMF Core Team, Cecelia DeLuca/ESMF Core Team, Jon Goodall/University of South Carolina
For questions on this project, please contact curator_hydro@list.woc.noaa.gov.
Motivation
In order to examine the effects of environmental changes on local watersheds, it has become increasingly important to be able to interoperate between diverse models and document and share the resulting data. To this end, we are prototyping an end-to-end workflow that executes multiple, distributed models, loosely coupling the model components, and disseminating the model results and metadata using a data portal. The models being coupled are a high performance atmospheric model (currently represented by a stubbed-out ESMF Component) and the hydrological model, SWAT (Soil and Water Assessment Tool). Each model is accessed via standard interfaces (OpenMI, ESMF), set up as web services, and in the final product, the resulting data will be published to the ESG (Earth System Grid) data portal. Managing the model execution and coupling is initially handled by the OpenMI Configuration Manager, to eventually be replaced by a more extensive workflow application, such as Kepler. The resulting product is an end-to-end, self-describing and repeatable workflow that demonstrates one-way interactive systems involving climate and other models can be created to address emerging questions about climate impacts
Approach
This project seeks to utilize the Earth System Modeling Framework (ESMF)) and OpenMI to couple a global atmospheric model with a hydrological model. Both systems will be controlled by an overarching driver and the data from both systems will be archived and described on a common science gateway.
Earth System Modeling Framework
ESMF is a high-performance, flexible software infrastructure that increases the ease of use, performance portability, interoperability, and reuse of Earth science applications. ESMF provides an architecture for composing complex, coupled modeling systems and includes data structures (Arrays, Fields, and States) as well as utilities for developing individual models. The software includes tools to describe and organize models and the ability to interface with model components via web services.
OpenMI
OpenMI is a software library that provides the hydrological community with a standardized interface that focuses on time dependent data transfer. It is primarily designed to work with systems that run simultaneously, but in a single-threaded environment. Regridding and temporal interpolation are also part of the package.
System Architecture
Below is a diagram of the system architecture. At the highest level, this coupled system is comprised of three main components: a hydrological model, an atmospheric model, and a driver application. The atmospheric model is implemented as an ESMF component and is wrapped with an OpenMI interface, which facilitates the communication with the OpenMI-compliant hydrological model. The hydrological model, driver, and the two OpenMI wrappers physically exist on a personal computer running Windows. The ESMF component itself exists on a multi-threaded Linux computer. An ESMF web services interface is used to bridge the two computer platforms.
Soil Water Assessment Tool (SWAT)
The hydrological model chosen for this project is the Soil Water Assessment Tool (SWAT). It is a river basin scale model developed to quantify the impact of land management practices in large, complex watersheds. It was chosen for this project because it is widely used, is open source, and runs on a Windows platform. The OpenMI version that has been made into a LinkableComponent, was downloaded with permission from the United Nations Educational, Scientific and Cultural Organization- Institute for Water Education (UNESCO-IHE). Inputs to SWAT include maximum and minimum temperatures, daily precipitation, relative humidity, solar radiation data, and wind speed data
Community Atmospheric Model (CAM)
CAM is part of the Community Climate System Model (CCSM), It is an atmospheric model that runs on a high-performance computing (HPC) Unix-based platforms. In order to interface CAM with SWAT, an OpenMI interface will be implemented on the Windows platform that will include a wrapper class that implements the OpenMI interface on the front-end, and remotely accesses CAM on the backend. Access on the backend will be handled using ESMF's web services protocol that interfaces with the model via an ESMF Component.
Earth System Grid (ESG)
The Earth System Grid is a federated data service specializing in the archival of geoscience data. Its evolving capabilities include tools to explore and compare datasets and the models that created them.
References
End-to-End Workflows for Coupled Climate and Hydrological Modeling, Edwin Sumargo (University of Illinois), Kathy Saint (SGI) and Sylvia Murphy (NOAA/CIRES), SIParCS Final Presentation, July 27, 2010. (Download PowerPoint file)
End-to-End Workflows for Coupled Climate and Hydrological Modeling, Kathy Saint (SGI) and Sylvia Murphy (NOAA/CIRES), iEMSs 2010, Ottawa Canada, July 5-8, 2010 (Download PowerPoint file)
Saint, K., and S. Murphy (2010. End-to-End Workflows for Coupled Climate and Hydrological Modeling, Accepted at the International Environmental Modelling and Software Society (iEMSs) 2010 International Congress on Environmental Modelling and Software Modelling for Environment's Sake, Fifth Biennial Meeting, Ottawa, Canada (Download PDF)
Source Code
The code for this system and instructions to reproduce our results is publically available on SourceForge at: esmfcontrib/HydroInterop
