IN21B-1055 INVITED
A COUPLED AIR/OCEAN/WAVE MESOSCALE PREDICTION SYSTEM
A significant advance in the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) is described. Using the Earth System Modeling Framework (ESMF), the COAMPS atmospheric model together with the NRL Coastal Ocean Model (NCOM) and a wave model are integrated into a relocatable, single executable application. Careful code design maintains the integrity of each model, allowing each to function both within the coupled system and as a stand-alone model. Exchange of fields between components, which may execute on non-overlapping sets of processors, is efficiently handled by the regridding and inter- processor communication methods provided by ESMF. Description of how the system is used to study air/ocean/wave coupling and its impact on some regional weather scenarios is also presented.
IN21B-1056
Two-Way Coupled Watershed-Nearshore Modeling Using DBuilder and ESMF
Since 2005, the DoD High Performance Modernization Program has sponsored the Battlespace Enivronment Institute (BEI) to migrate existing DoD climate/weather/ocean modeling and simulation, environmental quality modeling and simulation and space weather applications to the Earth System Modeling Framework (ESMF). One task in the BEI is to perform the coupling of two finite element models---a watershed model (pWASH123D) and a nearshore model (ADCIRC)---with the ESMF and DBuilder (a parallel data management toolkit) to provide the software architecture and parallel data management including all the functional support for data exchange between two models. The coupler component leverages the provision of the "nodes to elements" mapping along the coupling interface of these two models. On the coupling interface, the water level that ADCIRC simulates is imposed as the boundary condition for pWASH123D, while the nodal fluxes computed from pWASH123D serves as source/sink terms to ADCIRC. This presentation will include (1) the ESMF framework for control of the models, (2) DBuilder coupler interface, (3) parallel algorithms in DBuilder for couplers, and (4) two test examples for demonstration. One demonstration example presents the watershed and nearshore storm surge simulation around the Biloxi Bay area during the Hurricane Katrina in August 2005.
IN21B-1057
Linking ESMF Applications With Data Portals Using Standard Metadata
This talk describes the development of a prototype data portal to support a NCAR Advanced Study Program colloquium entitled Numerical Techniques for Global Atmospheric Models, held in Boulder during July, 2008. The colloquium focused on the comparison of thirteen atmospheric dynamical cores, a key element of next- generation models. Dynamical cores solve the governing equations that describe the properties of the atmosphere over time, including its motion. An efficient, accurate dynamical core is needed to achieve the high spatial resolutions that can improve model fidelity and enable the model to span predictive scales. In support of this event, ESMF, the Earth System Curator project, and the Earth System Grid (ESG) collaborated on the creation of a prototype portal that relies on standardized metadata to directly link datasets generated at the colloquium with information about the model components that generated them. The system offers tools such as dynamically generated comparison tables, faceted search, and trackback pages that link datasets to model configurations. During the colloquium, the metadata describing the dynamical cores was provided by the participants and manually added to the portal. Since then two developments have occurred to facilitate two important steps in the metadata lifecycle: creation of the metadata and ingestion into data archives. First, ESMF has been modified to enable users to output metadata in XML format. Because ESMF data structures already contain information about grids, fields, timestepping, and components, it is natural for ESMF to write out internal information in a standardized way for use by external systems. Second, modifications to the prototype portal were completed this summer to enable XML files output by ESMF to be ingested automatically into the portal. Taken together with the prototype web portal, the new metadata-writing capabilities of ESMF form part of an emerging infrastructure in support of the full modeling workflow, including metadata generation, metadata curation, and discovery services for scientists and other end users. This integrated approach to modeling and data archival encourages controlled experimentation of the sort demonstrated at the dynamical core colloquium and facilitates intercomparison and interoperability of model components and output datasets. This talk will cover the technical details associated with ESMF's new capabilities, discuss the end-to-end workflow created, review some of the colloquium metadata, and finally discuss the rationale for the use of XML and RDF/OWL as the conceptual representation of the generated metadata.
IN21B-1058
Coupling HYCOM and CICE Using ESMF
The Hybid Coordinate Ocean Model (HYCOM) and the Los Alamos Sea-Ice Model (CICE) have been coupled on the same horizontal grid using the Earth System Modeling Framework (ESMF). Details of the coupling and initial results will be discussed.
IN21B-1059
Use of ESMF in the GEOS-5 Modeling and Assimilation System
The GEOS-5 system was developed during the last five years, alongside the development of ESMF. It was, therefore, designed and built as an ESMF-based system. It consists of some thirty ESMF gridded components connected in a hierarchical topology, using fine-grained ESMF componetization. In the atmospheric GCM, in particular, ESMF components are used down to the level of individual parameterizations. To maintain a uniform structure over some many ESMF components, we needed to develop standard methods and practices for using ESMF. These standards were codified in an ESMF-based software layer called MAPL. MAPL-ESMF gridded components are easily coupled and manipulated within the GEOS-5 structure, but appear as ordinary, fully-compliant ESMF gridded components if used in non-MAPL applications. The use of ESMF's component design has allowed us considerable flexibility in extending the GEOS-5 system. The current atmospheric model, for example, runs seamlessly with two dynamical cores: either the traditional latitude-longitude core or one recently developed at GFDL using a cubed-sphere grid. The development of this capability was greatly simplified by the MAPL-ESMF design. The coupled atmospheric-ocean model uses the MOM4 OGCM, also developed at GFDL, which has been wrapped as a MAPL-ESMF that allows us to keep up with the latest distributions coming from GFDL. Several atmospheric chemistry and aerosol components are also available, most notably the GMI chemistry and the GOCART aerosol model, which also run in the system with MAPL-ESMF wrappings. Finally, MAPL-ESMF versions of the radiation and fast physics used an NCEP and of the MIT ocean GCM have been developed and are now being tested as optional components in the system. In addition to the model components, GEOS-5 also includes analysis components for assimilation atmospheric, oceanic and land surface data. These components are also integrated in the system using the MAPL-ESMF methodology, which is now supporting both 3d_var and Ensemble Kalman filter approaches. A 4d-VAR atmospheric assimilation with forward and adjoint components is also in advanced stages of testing.
IN21B-1060
Superparmeterization in Ocean Modeling Using General Multiscale Techniques: A Deep- Convection Case Study Employing ESMF.
Multiscale approaches allow explicit modeling of the many different phenomena that are present in real ocean dynamics. In this work we use multiscale-superparameterization approach to efficiently model oceanic deep- convection. We present results and methodology for a multiscale simulation in which several hundred high-resolution, two-dimensional, non-hydrostatic process models are coupled, as separate ESMF components, to a large-scale hydrostatic ocean model. One process model is embedded in each grid cell of the large-scale three-dimensional hydrostatic model. The process models take the place of conventional one-dimension empirical parameterizations, producing a simulation more accurately grounded in underlying physical equations. The individual MITgcm process models, and the hydrostatic MITgcm model into which they are embedded, are implemented as ESMF components. The ESMF library is used to orchestrate data flows between components and to steer the overall computation, including spreading the workload over multiple parallel processors. We measure the impact of our approach, in terms of both improved numerical accuracy and computational cost, by comparing quantitative metrics with respect to a fully resolved, three-dimensional, non-hydrostatic "ground- truth" simulation. In comparison with a purely hydrostatic numerical experiment, the time evolving state and statistics of the multiscale system are found to be significantly closer to the ground-truth model solution. For example, in the embedded simulation, the slanting of convective plumes due to large scale flow vertical shear is reproduced and higher order statistics, such as the variance and skewness of the model fields, are all much closer to the ground-truth model solution. The improved accuracy of the multi-scale model is achieved for a computational cost far less than that of a fully resolved non-hydrostatic model. By exploiting parallelism amongst the embedded models, we can achieve a wall-clock time to solution that is a small multiple of a pure hydrostatic simulation. The approach we have taken is by no means limited to parameterization of deep convection and can be generalized fairly broadly. For example mixed-layer processes, biogeochemical processes, eddy flux coefficients could all be estimated by appropriate local, prognostic sub-models that are then coupled to a larger scale model, provided the factors and analysis we described are appropriately considered.
IN21B-1061
Utilizing Kernelized Advection Schemes in Ocean Models
There has been a recent effort in the ocean model community to use a set of generic FORTRAN library routines for advection of scalar tracers in the ocean. In a collaborative project called Hybrid Ocean Model Environement (HOME), vastly different advection schemes (space-differencing schemes for advection equation) become available to modelers in the form of subroutine calls (kernels). In this talk we explore the possibility of utilizing ESMF data structures in wrapping these kernels so that they can be readily used in ESMF gridded components.
IN21B-1062
Using InterComm Enhanced ESMF to Couple TIME-GCM and CAM
This project uses the Earth System Modeling Framework (ESMF) and InterComm to produce a TIME-GCM and CAM coupled model. This project will demonstrate a new ESMF capability for coupling models running as separate executables. This capability is based on the InterComm library. InterComm is a runtime library and programming model for coupling separately executing parallel (and sequential programs), and is being used as the component coupling technology within the NSF Center for Integrated Space Weather Modeling. ESMF interfaces to InterComm have been contributed to the ESMF code repository, making it easy to use InterComm to transfer data into and out of ESMF components such as CAM. This project's work to couple TIME-GCM and CAM is motivated by the goal of understanding the day-to-day behavior of the ionosphere-thermosphere system. Doing this requires unraveling the relative strengths of forcing mechanisms of the I-T system, including solar ultraviolet, extreme-ultraviolet, and X-ray fluxes, magnetospheric processes resulting in geomagnetic activity and auroral effects, and propagation of dynamical variations driven by lower atmosphere weather and middle atmosphere tides. The National Center for Atmospheric Research (NCAR) Thermosphere - Ionosphere - Mesosphere -Electrodynamic - Global Circulation Model (TIME-GCM) is used to simulate this region depending on its forcing by the Sun. Recent work on improving the forcing of this model by including an improved description of the Extreme Ultra Violet (EUV) radiation has increased its ability to predict observed parameters such as satellite drag, but it does not capture all the observed hemispheric asymmetries. The implication is that forcing from the lower atmosphere, which is clearly asymmetric due to the location of continental masses, and is known to have very different dynamical features at solstices, is controlling the thermosphere. However, the TIME-GCM, with its 30-km lower boundary, does not contain these effects. The Community Atmosphere Model (CAM) simulates the variation in the atmosphere, and by coupling it to the TIME-GCM we plan to investigate how much of these asymmetries can be addressed by this forcing from below.
IN21B-1063
The Space Weather Modeling System: An ESMF Compliant Solar Wind and Ionospheric Forecast System
Ionospheric storms can severely impact communications, navigation and surveillance systems. These ionospheric disturbances are driven by solar activity. A key challenge in space science is to understand the causes of the ionospheric response to solar forcing. Attempting to accurately forecast the time-dependent behavior of the ionosphere is the only way to truly test our understanding of the ionosphere. Space weather forecasters for the DoD face this challenge on a daily basis. The Air Force Weather Agency is meeting this challenge through the development of an operational Space Weather Modeling System (SWMS). The SWMS is a Battlespace Environments Institute (BEI) project that couples Earth system environmental models together under the Earth System Modeling Framework (ESMF). BEI is sponsored by the High Performance Computing (HPC) Modernization Office. The first two coupled components in SWMS are the Hakamada-Akasofu-Fry version 2 (HAFv2) solar wind model and the Global Assimilation of Ionospheric Measurements (GAIM) model. The HAFv2 model produces quantitative forecasts of solar wind parameters at Earth and elsewhere in the inner heliosphere. The Ionosphere Forecast Model (IFM) is the physics-based ionosphere model within GAIM. IFM provides highly representative specifications of plasma conditions in the global ionosphere. The one-way coupling of HAFv2 to IFM links the solar storm drivers to the ionospheric response. Predicted solar wind quantities are fed as inputs to IFM, which computes the solar wind energy deposition into the high latitude ionosphere, enabling GAIM to provide multi- day forecasts of ionospheric electron density, currents and upper atmosphere dynamics. The SWMS development is a structured project, moving from partial to full ESMF compliance. Bringing the HAFv2 and IFM models into the ESMF allows significant improvements in computational efficiency and data throughput. Modifying these computer codes for the HPC environment opens the door for other new capabilities. These include the ability to: 1) ingest diverse data sets at higher resolution and cadence; 2) use denser computational grids; and 3) perform ensemble forecasts. The HAFv2-IFM coupling provides the first operational, physics-based forecasts of the near-earth space environment that anticipate solar storm effects. The SWMS effort will shed light on our understanding of the underlying physics and ultimately lead to more accurate ionospheric forecasts to better support DoD missions
IN21B-1064
Quantifying the impact of different ESMF regridding algorithms in a simplified coupled geophysical flow problem as coupled system resolution ratio is varied.
The Earth System Modeling Framework (ESMF) supports generalized regridding algorithms that are designed for flexibly coupling models at different spatial and temporal scales. In the context of atmosphere ocean modeling these ESMF capabilities provide a solid basis for coupled experiments in which atmosphere and ocean components are configured independently with significant differences in spatial and temporal resolution. In these scenarios the choice of regridding method can introduce numerical artifacts. In this talk we look at the impact of different ESMF regridding algorithms in a range of idealized scenarios in order to develop guidance on when one regridding algorithm should be favored over another. The results provide useful pointers for coupled experiments connecting atmospheric and ocean simulations on different meshes and at different resolutions. Our approach uses the classic Stommel ocean gyre problem as its basis. In this problem an ocean gyre is driven by surface wind-stress and the equilibrated solution is a balance between vorticity input from the wind and dissipation due to mixing and boundary drag. For our study we configure an MITgcm ocean ESMF component and a pseudo atmosphere ESMF component that maps an analytical wind stress to an arbitrary numerical mesh. Using different ESMF regridding schemes we vary the ratio of the atmosphere to ocean mesh resolution and the absolute ocean resolution. The results clearly illustrate the benefits of preserving C2 or greater continuity in interpolation schemes for problems where the ratio of mesh resolutions is large. Finally we repeat selected experiments for a, simple geometry, global ocean simulation, showing how the same rules hold. This work illustrate the flexibility now available in ESMF and assesses accuracy and computational cost trade offs and inherent biases associated with interpolation algorithm selection.
IN21B-1065
The Incorporation of ESMF at NCEP
The Earth System Modeling Framework (ESMF) is being incorporated in the operational prediction models at the NOAA National Weather Service's National Center for Environmental Prediction (NCEP). ESMF will be used to couple several large geophysical models together, as well as to couple the atmopheric dynamics and physical parameterization package together. In addition, the nesting of atmospheric models is being developed using ESMF. The model clock, grid, state data, and metadata are managed using ESMF.
IN21B-1066
Social Science Studies of ESMF as Cyberinfrastructure: A New Project
Model-based cyberinfrastructure has dramatically integrated a few fields, such as global operational weather forecasting. In many research disciplines, however, modeling remains a form of craftwork. Models are often the signature products of individual labs and investigators. Complex scientific models often are poorly documented, requiring hands-on experience and tacit knowledge, so that even where model sharing is an explicit goal, in practice investigators have often found it easier to build new ones. The Earth System Modeling Framework offers the promise of sharing models and model components more easily, but the problem of incentives to meet and maintain framework standards remains substantial. Emergent cyberinfrastructures such as ESMF can vastly enlarge the range of potential users. Therefore, issues of trust, institutional structures, and other social dynamics may be more problematic than technical concerns in effective implementation. This paper presents a new project by an interdisciplinary team of social scientists to investigate these dynamics. Ethnographic, historical, and information-scientific methods will be applied in a three-year, longitudinal study of four multi-disciplinary, multi-institutional cyberinfrastructures, with ESMF as one of four target projects. Results from an earlier pilot study of issues in scientific cyberinfrastructure will be presented.