Simulation of Storm Surge Using Grid Computing

Grid computing is emerging as an attractive approach to solve large problems of importance to the estuarine and coastal modeling community through the coordinated sharing of resources. Using the simulation of storm surge as a proxy for a typical estuarine and coastal modeling application, two examples of computation using Grid computing are undertaken. The applications used in the examples are Grid-enabled through virtualization techniques available through the In-VIGO web portal and Grid middleware. Virtualization allowed both examples to be Grid-enabled without modification of the source codes in any way, thus requiring minimal IT expertise by the modeler. In the first example, regional Grid computational resources at three institutions, UF, LSU and VIMS are used to perform a series of ensemble simulations of storm surge using the CH3D component of the CH3D Storm Surge Modeling System (CH3D-SSMS). Ensembles consist of the response of Tampa Bay, FL to various forecasted tracks of Hurricane Charley (2004). The Grid-calculated ensemble Maximum of Maximum (MOM) water level is identical to the MOM simulated on a single host or set of resources at one institution with the advantage that the computations can be performed in parallel across the regional Grid's resources. A 1% increase in wall clock time is shown when solving the simulations on different Grid resources. In the second example, the execution of the local-scale surge model (CH3D), the local-scale wave model (SWAN) and the regional-scale surge model (ADCIRC) components of the CH3D-SSMS are used to determine if coupled modeling systems can perform adequately across Grid resources. With CH3D running at VIMS, SWAN at LSU and ADCIRC at UF and coupling performed via simple file I/O through a virtual file system, the entire coupled system shows an increase in wall clock time of 13%. As with the ensemble simulations, simulated parameters are identical to those computed on one host. The relative ease of Grid-enabling both examples combined with the minimal increase in wall clock time demonstrates that typical estuarine and coastal modeling applications can successfullly use Grid technologies across a regional Grid, which, in turn, opens up estuarine and coastal modeling to the possibility of using resources from larger Grid projects, e.g. SURAgrid or Open Science Grid.