Cold fronts control multiscale spatiotemporal hydroperiod patterns in a man-made subtropical coastal delta (Wax Lake Region, Louisiana USA)

Atmospheric cold fronts quasi-periodically produce storm surges and generate significant subtidal oscillations of water levels and water transport in coastal environments. Yet, it is unclear how these weather events—at regional scales —control the hydrodynamics in delta-dominated coasts. Here, we used a numerical model (SCHISM) to simulate the inundation/drying and water circulations generated by varying winds associated with cold front passages across the Atchafalaya Bay in the northern Gulf of Mexico, specifically the Wax Lake Delta (WLD) region. Water transport induced by winds through major channels of the WLD and that between the adjacent Vermilion Bay and inner shelf were quantified to evaluate the impact of cold fronts. Results show that significant wetting/drying conditions are highly correlated with wind direction and strength. Southerly/easterly winds tend to cause water set-up, thus inundating the delta region, while northerly and westerly winds cause water set-down, draining the bay into the continental shelf. As a result, up to 60