The Coastal Storm Modeling System (CoSMoS) applies a predominantly deterministic framework to make detailed predictions (meter-scale) of storm-induced coastal flooding, erosion and cliff failures over large geographic scales (100s of kilometers). CoSMoS was developed for hindcast studies, operational applications (i.e., nowcasts and multi-day forecasts) and future climate scenarios (i.e., sea level rise + storms) to provide emergency responders and coastal planners with critical storm hazards information that may be used to increase public safety, mitigate physical damages, and more effectively manage and allocate resources within complex coastal settings.
Although the modeling system was initially developed for use on the high wave energy environment of the U.S. West Coast, CoSMoS is not empirically-based, and can be utilized on sandy and/or cliff-backed coasts throughout the world. The prototype system, developed for the California coast, uses the global WAVEWATCH III wave model, the TOPEX/Poseidon satellite altimetry-based global tide model, and atmospheric forcing data from either the U.S. National Weather Service (operational mode) or Global Climate Models (future climate mode), to determine regional wave and water level boundary conditions, which are dynamically downscaled using a series of nested Delft3D wave (SWAN) and tide (FLOW) models. These data are ultimately linked at the coast to tightly-spaced XBeach (eXtreme Beach) cross-shore profile models and a Bayesian probabilistic cliff failure model.
Above: CoSMoS model framework illustrating interactions amongst the global, regional, and local models, boundary data used to drive the models, and model outputs used to produce local flood projections. [Larger version]
CoSMoS has been used and is in development for several applications: