Section: Application Domains

Ocean-Atmosphere Simulations

Climatologists have recourse to numerical simulation and particularly coupled models in several occasions: for example, to estimate natural variability (thousand of simulated years), for seasonal forecasting (only a few simulated months) or to study global warming characteristics (some simulated decades).

To take advantage of the Grid'5000 platform, we choose to launch parallel simulations (ensemble) on several nodes, approximatively 10 or more, according to the load of the platform. Scenario simulations, that simulate from present climate to the next century, require huge computing power. Indeed, each simulation will differ from each other in physical parameterization of atmospheric model. Comparing them, we expect to better estimate global warming prediction sensibility in order to model parameterization.

Practically, a 150 year long scenario combines 1800 simulations of one month each, launched one after the other. This partitioning eases workflow and implements checkpointing because the ending state of the simulation of one month is used as the initial state of the next month.

Our goal regarding the climate forecasting application is to thoroughly analyze it in order to model its needs in terms of execution model, data access pattern, and computing needs. Once a proper model of the application has been derived, appropriate scheduling heuristics can be proposed, tested, and compared. We plan to extend this work to provide generic scheduling schemes for applications with similar dependence graphs.