Subtidal exchanges between Corpus Christi Bay and Texas inner shelf waters

Air pressure and water level data from the Texas coast, along the northwestern rim of the Gulf of Mexico, are used to infer surface winds tress and investigate subtidal, meteorological forcing in a cause-and-effect sense. A 49-day study period in 1972 is selected to investigate the response of shelf waters to windstress forcing. The cross-shelf component of windstress, as inferred from the surface pressure gradient, forces bay-shelf exchanges over time scales of 2-4 days; the longshore component of windstress is coherent with bay-shelf exchanges over longer time scales, suggesting a cross-shelf EKMAN transport. A 196-day study in 1975 documents inverse barometric forcing over time scales in excess of about two days. A one-dimensional numerical model simulates the tidal and nontidal influx of Gulf water into Corpus Christi Bay as a response to coastal water level variations. Results suggest that tidal exchanges dominate subtidal exchanges in this coastal setting. Tidal forcing pumps Gulf water into the Bay at an average rate of 17 million cubic meters per day; nontidal forcing imports water to the Bay at an average rate of approximately l4 million cubic meters per day.