EFFECTS OF METEOROLOGIC EVENTS ON WAVE CLIMATE AND CURRENT REGIME IN A SHALLOW, MICROTIDAL BAY

Along coastal Louisiana and within the shallow microtidal Barataria Bay estuary, meteorological events can play a primary role in influencing wave climate and circulation patterns. Understanding the effects of hurricanes and smaller tropical storms on hydrodynamic processes is important for constraining and predicting hydrodynamic variation in Barataria Bay, which, largely due to impacts from wave energy, is currently experiencing rapid wetland loss and is a major focus of coastal restoration efforts. Two bottom-mounted upward-facing Acoustic Current Doppler Profilers and wave, temperature, and depth recorders were installed in the lower portions of Barataria Bay to measure the wave climate and three-dimensional current velocities. These data were used to constrain wave action and current velocity responding to the passage of meteorological events in the fall of 2020 and summer of 2021. Fetch distance, water depth, and local wind speed were used as variables in a linear wave theory model that predicts significant wave height. Model results indicate that variation in fetch contributes relatively more to the overprediction of wave heights during storms compared to depth variation, which results in nearly negligible impacts on wave height prediction within Barataria Bay. In the quiescent periods between events, wave heights and propagation directions were much less predictable, as wind direction had a wider range and magnitude decreased substantially. Analyses of depth-averaged velocities suggests diurnal constituents dominate periodicity. Storms that made landfall to the west of the bay resulted in enhanced subtidal current magnitude during pre-and post-landfall periods while the recorded storm that made landfall to the east of the bay showed much less subtidal current response. The results shed light on the impacts of extreme events on circulation and wave climate in Barataria Bay, with implications for suspended sediment transport in a degradational coastal system