Simulation and prediction of storm surges and waves using a fully integrated process model and a parametric cyclonic wind model

Authors: DING, YAN - Us Army Corp Of Engineers (USACE); DING, TAIDE - Stanford University; RUSTIN, ANDI - Tadulako University; ZHANG, YAOXIN - University Of Mississippi; JIA, YAFEI - University Of Mississippi

Submitted to: Journal of Geophysical Research: Oceans
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/14/2020
Publication Date: 5/19/2020
Citation: Ding, Y., Ding, T., Rustin, A., Zhang, Y., Jia, Y. 2020. Simulation and prediction of storm surges and waves using a fully integrated process model and a parametric cyclonic wind model. Journal of Geophysical Research: Oceans. 125.e2019JC015793. https://doi.org/10.1029/2019JC015793.
DOI: https://doi.org/10.1029/2019JC015793

Interpretive Summary: Coupled storm surge and wave models have been widely used for predicting coastal flooding and inundation induced by hurricanes. However, most models are computationally expensive. The methods used to couple physical mechanisms (submodels) are often cumbersome and in-accurate. In the paper, a fully integrated coastal process model, CCHE2D-coast, and a novel parametric wind model are presented to predict hurricane wind, storm surges, waves, tidal currents, and river flows. All the submodels are written into a single code, sharing with the same computational grid, and passing information between submodels through local memory/cache. By using a regional-scale high-resolution mesh for the northern Gulf Coast, this model was successfully validated for reproducing winds, waves, tides, and river inflows in Hurricane Gustav (2008). This site-specifically validated model was then applied to forecast real-time storm surge flood using the advisory tracks of Hurricane Isaac (2012). High efficiency and accuracy coast-flood solutions can be achieved by this fully integrated model using a PC.

Technical Abstract: This paper presents a fully integrated coastal process model and a simple parametric cyclonic wind-pressure model for simulation of wind, storm surges, waves, tidal currents, and river flows. By sharing one computational grid within all those process modules and no need for switching executable codes from one module to another, this full-coupling feature eliminates possible errors and loss of information due to interpolation and extrapolation of variables between different grids. To generate better cyclonic wind speed and barometric pressure, this parametric wind model includes nonlinear decay effect on wind intensity after hurricane's landfall. By implementing a new wind energy source term, the wave action model is capable of computing wave growth, propagation, and deformation through a regional-scale domain from deepwater to shallow waters. Model validation and model skill assessment were performed by hindcasting wind, storm surges, waves, and river flows during Hurricane Gustav (2008) by using a high-resolution grid covering the northern Gulf Coast. With improved wind fields estimated by the new parametric wind model, this fully integrated process model produced high-quality wavefields in deep and shallow waters and storm tidal levels in the northern Gulf Coasts. Because of computing efficiency provided by seamless integration of process modules and optimized numerical solution schemes, faster-than-real-time predictions of storm surges for the advisories during Hurricane Isaac (2012) were achieved by running the validated model in a desktop computer.