Forecasting the Environment of the Littoral Waters in the Northern Gulf of Mexico

Abstract

A regional scale forecasting system of the Mississippi Sound and Bight and adjoining estuarine and bay systems has been developed as part of the Northern Gulf of Mexico Littoral Initiative (NGLI) to provide a reliable means of predicting the littoral circulation and salinity structure of the region. The modeling framework adopts a high-resolution orthogonal curvilinear grid, which resolves the relevant bathymetric and coastline features, especially the area in the vicinity of the barrier islands and ship channels. The Mississippi Sound and Bight model represents the highest spatial resolution component of a triple-nested series of three-dimensional circulation models. At its eastern and southern boundaries, the Mississippi Sound and Bight model is coupled to a regional Gulf of Mexico model, which in turn is coupled to a global circulation model. Spatially variable wind and pressure fields generated from an operational Navy atmospheric circulation model have been integrated in the modeling system. The model has been calibrated for the January–April 2000 period. The estuarine processes controlled by winds and freshwater discharges have been identified and quantified for Mobile Bay, Biloxi Back Bay and Bay St. Louis through a series of model sensitivity simulations. During the initial efforts of the NGLI, significant improvements and enhancements have been made to the model and the modeling system. The focus will now shift towards model calibration/validation, sensitivity analysis and maintaining the operational status of the modeling system.