''Grid''-based Particle Tracking in Florida Bay

In recent years, grid computing has emerged as an attractive approach to solve large problems through the coordinated sharing of resources. While successful in other fields, e.g. high energy physics, few studies focusing on coastal and estuarine problems have been performed; thus, a pilot study was performed to illustrate how coastal and estuary modeling could use grid computing technologies. To this end, several coastal and estuarine models were dynamically coupled and then executed in a local computational grid environment composed of Silicon Graphics computers connected by a fast ethernet network. The models: a robust hydrodynamic model (CH3D), a particle tracking model, and a visualization model communicated through the network using a grid-enabled version of MPI, MPICH-G2. The grid-enabled, coupled modeling system was then tested on a real estuary, Florida Bay, USA. Using simulated hydrodynamics (Node 1), the trajectories of 2000 particles were simulated by two independent instances of the particle tracking model (Nodes 2 and 3). Updated particle positions were then visualized (Node 4) and compared with those calculated with a statically coupled version of the modeling system running on a single node. The dynamically coupled system was shown to reproduce the particle trajectories exactly with some speedup due to the two particle tracking models running in parallel. A graphical interface to the modeling system was then created using the advanced web portal and grid middleware software In-VIGO. The robustness of the results shown along with relative ease of converting an existing modeling system into a dynamically coupled system running in a grid environment demonstrated the feasibility of using grid technologies on coastal and estuarine modeling.