Atmospheric Influence Over the Residence Time in the Bahia Blanca Estuary, Argentina

An integrated hydrodynamic and Lagrangian transport model was used to estimate the average residence time in the Bahia Blanca estuary (Argentina) for wind conditions of different seasons. The Bahia Blanca estuary consists on an elongated system of meandering bays surrounded by tidal flats and salt marshes where the tide is the principal forcing. Modelling results show that both the tidal amplitude and wind forcing affect significantly the residence time, since river discharge is very low. An increase in the wind intensity along the bays main axis causes a considerable increase in the intensity of the residual current and thus a modification of the average residence time over the model domain. In all seasons, the overall residence time ranges from 12 to 77days. The values allow establishing a hydrodynamic performance for each of the estuary sectors over each seasonal period. These findings provide useful information to quantify the transport processes on the different sectors of the Bahia Blanca estuary necessary to understand temporal and spatial variations.