 |
|
 |
||||||
|
||||||
 |
Home
| Mission
|
about SciDAC
|
Contact Us |
|||||
 |
 |
 |
||||
|
Alumni ProjectDecadal Regional Climate Studies and Applications with Variable-Resolution GCMs Using Advanced Numerical Techniques J. Côté, SummaryThis study is devoted to research in parallel computing and numerical methods, atmospheric chemistry related to climate issues, validation of regional climate modeling strategies for nested- and stretched-grid models, decadal time-scale investigation with the Global Environmental (GEM) model, the limited-area version of GEM model experiments with the same regional resolution. This project reflects a trend in the modeling and broader communities to move towards regional and sub-regional assessments and applications important for the U.S. and Canadian public, business and policy decision makers, as well as for international collaborations on regional, and especially climate related issues. This study is done collaboration with M. Fox-Rabinovitz et al. from the Univ. of Maryland.The research has led to the distributed memory version of the Global Environmental Multiscale (GEM) model being implemented as an operational weather forecast model for North America. It is now evaluated for forecast at 15 km rather that 24 km, almost doubling the number of degrees of freedom. A crucial element was the use of solvers based on optimized matrix multiplication kernels. We have been also investigating efficient parallel iterative methods. The hybrid vertical coordinate system for the GEM model has been further tested and implemented both for global and mesoscale modeling.
The LAM and SGMIP also show similar surface results, although more works needs to be done over the LAM's nesting areas. A more comprehensive comparison will shortly be done of the three model configurations in a further investigation of one- and two-way nesting strategies with the Big Brother Experimental Setup, which is a rigorous and well-defined experiment used for addressing some important one-way nesting issues. In the next year or two, we plan to continue research on iterative methods for massively parallel computers with performance in the Teraflops range. We intend to pursue the second phase of the international Stretched Grid Intercomparison Project (SGMIP) initiated by our collaborator M. Fox-Rabinovitz. Our interactions with other teams of SciDAC have been mainly though specialized workshops such as “Partial Differential Equation on the Sphere” and the Canadian Regional Climate Modeling Meeting. We have close contacts with the joint team at the U. of Maryland and with the Program for Climate Model Diagnosis and Intercomparison (PCMDI) team at Lawrence Livermore National Laboratory which is responsible for the AMIP2 project. Reference Caya, D., and S. Biner, 2003: Internal variability of RCM simulations over an annual cycle. Climate Dyn. , 24 , 33-46. de Elía, R., and R. Laprise, 2003: Predictability of Limited-Area Models: Twin and Big-Brother Experiments. Research activities in Atmospheric and Oceanic Modelling, WMO/TD , J. Côté, Ed., 1161 (33): 5.7-5.8. Denis, B., R. Laprise, and D. Caya, 2003: Sensitivity of a regional climate model to the resolution of the lateral boundary conditions. Climate Dyn. , 20 , 107-126. Édouard, S, B. Dugas, 2003: The Use of a hybrid vertical coordinate in the CMC-MRB Global Environnemental Model (GEM) model. Research activities in Atmospheric and Oceanic Modelling, WMO/TD , J. Côté, Ed., 1161 (33): 6.3-6.4. Erfani, A., A. Méthot, R. Goodson, S. Bélair, K.-S. Yeh, J. Côté and R. Moffet, 2003: Synoptic and mesoscale study of a severe convective outbreak with the non-hydrostatic Global Environmental Multiscale (GEM) model. Meteor. Atmos. Phys. 82 , 31-53. Laprise, R., 2003: Resolved scales and nonlinear interactions in limited-area models. J. Atmos. Sci. , 60, 768-779. Lucas-Picher, P., D. Caya, S. Biner, 2004: RCM's internal variability as function of domain size. Research activities in Atmospheric and Oceanic Modelling, WMO/TD , J. Côté, Ed., (34), 2 pages. Qaddouri, A., and J. Côté, 2003: Preconditioning for an iterative elliptic solver on a vector processor. High Performance Computing for Computational Science -VECPAR'2002, Springer, Palma, Dongarra, Hernandez and Sousa Eds, 343-353. Qaddouri, A., and J. Côté, 2004: Optimization of a direct elliptic boundary value problem solver by the combined use of symmetry and Strassen's algorithm. Accepted by Mon. Wea. Rev. For further information on this subject contact:
|
|||||
Home | ASCR | Contact Us | DOE disclaimer |
|
|
Figure 1. The mean precipitation field for January obtained in the Stretched Grid Model Inter-comparison Project simulation.