Tidal Flats, Muddy Seafloors, Sandy Coasts, and Inlets

The long-term goal is to develop field-verified models for the evolution of surface-gravity waves, circulation, sediment transport, and the subsequent morphological response in shallow, coastal waters. The objectives of our studies in FY11 were to analyze observations of currents, waves, and bathymetry on tidal flats, and to develop, test, and improve models for tidal-flat processes. Specific goals related to tidal flats were to investigate the relative importance of riverine and tidal flows to the circulation and density stratification. Additional goals in FY11 included developing models for mud-induced dissipation of waves, analyzing waves, currents, and morphological change on sandy beaches, providing ground truth for remote sensing of littoral areas, and planning a study of waves and circulation in the vicinity of a strong, narrow jet of water at an inlet. Our approach is to collect field observations to test existing hypotheses, to discover new phenomena, to provide ground truth for remote sensing studies, to initialize and test data assimilative models that invert for bathymetry, and to calibrate, evaluate, and improve models for tidal flat hydrodynamics and morphological evolution and for waves propagating in shallow water across muddy and sandy seafloors.