The Atmospheric Forcing modeling components of CSTORM-MS provide the dominant driving force for coastal storm simulations. The accuracy of modeled waves, surges, and morphologic response is critically dependent on the accuracy of the wind and pressure fields used to force the coastal processes models. A robust storm atmospheric forcing system is an important research and development element of CSTORM-MS. Improvements have been made to wind and pressure field estimations for tropical storms within the planetary boundary layer (PBL) model. There is also easy access to hurricane and tropical storm databases, such as HURDAT, for creating and perturbing synthetic storms and for setting up, running, and visualizing PBL and other wind models.
The Wave modeling components include both a deepwater wave model (WAM) and nearshore wave model (STWAVE). CSTORM-MS is making advancements in critical wave modeling areas, including the improved representation of bottom friction and diffraction in STWAVE as well as improvements to the numerics within STWAVE that allow for the use of larger domains and finer resolutions and either half-plane or full-plane physics. GUI’s within the SMS have been added for both WAM and STWAVE and allow for easy set-up, running and result analysis for both models. A primary focus of the next spiral of developments for waves will be a new time-stepping unstructured wave model (TSWAVE) in an effort for advancement of both deepwater and nearshore wave modeling technology to include consistently scaled spectral source terms and the ability to accurately conform to complicated coastlines and coastal structures.
In general, the modeling of sediment movement and associated morphological changes has not undergone significant advancement in recent years in part due to the complexities involved and incomplete understanding of surf zone sediment processes. New physics-based tools are being developed within spiral 2 with capabilities to predict profile and shoreline change. CSTORM-MS nearshore technologies currently under development as part of spiral 2 include the Coastal 2D (horizontal) steady-state nearSHORE morphology response model (C2SHORE). This model includes such features as dune erosion and overtopping. The C2SHORE model is being incorporated into simulations of nearshore hydrodynamics by tightly coupling it with the Adaptive Hydrology/Hydraulics (ADH) model as part of a larger sediment library, SEDLIB.
Circulation and Storm Surge
CSTORM-MS is advancing the development of 2D and 3D circulation modeling technology for the accurate and reliable prediction of inundation and flooding from extra-tropical storms and hurricanes. Winds, tides, waves, rainfall, and river influx influence coastal circulation and storm surge levels. To simulate the effect these processes have on inundation, flooding, sediment transport, and beach erosion, CSTORM-MS is advancing the development of Advanced Circulation (ADCIRC) two- and three-dimensional modeling systems for setting up, running and analyzing model results within the SMS. This includes the use of the internal Holland wind models and the spatially varying datasets within ADCIRC.
Test and Evaluation
Modeling studies typically require many simulations to fully explore output sensitivity to a variety of controlled inputs, source-term settings, and grid resolution. The CSTORM-MS test bed links model output with historical data through robust statistical tools such as the Interactive Model Evaluation and Diagnostics System (IMEDS) for winds, waves, and water levels; and the Coastal Morphology toolbox (CMorph) for morphologic evolutions. Both of these tools provide an in-depth error analysis and performance assessment of model results to facilitate continued model improvements.
CSTORM-MS is a user-friendly integrated system of fully coupled coastal process modeling tools. A physics-based modeling capability must necessarily link the simulation of winds, water levels, waves, currents, sediment transport, and coastal response (erosion, accretion, breaching) during extreme events in an integrated system. A flexible and expandable computational coupler has been developed that utilizes the ESMF standards and currently links the atmosphere, circulation, and waves, and for spiral 2 will include nearshore dynamics models, like C2SHORE, for application on desktop computers or high-performance computing resources. The computational coupler employs a two-way coupling scheme that not only enhances the represented physics but also results in significant improvements in computational time when compared to file-based approaches.