Flow and suspended particulate transport in a tidal bottom layer, South San Francisco Bay, California

Field investigations of the hydrodynamics and the resuspension and transport of particulate matter in a bottom boundary layer were carried out in South San Francisco Bay, California during March-April 1995. The GEOPROBE, an instrumented bottom tripod, and broad-band acoustic Doppler current profilers were used in this investigation. The instrument assemblage provided detailed measurements of 1) turbulent mean velocity distribution within 1.5 m of sediment-water interface; 2) characteristics of 3-D tidal current in the water column; 3) friction velocity u. or bottom shear stress and bottom roughness length z(o); 4) hydrodynamic conditions conducive for sediment resuspension; and 5) circulation patterns which are responsible for transporting suspended particulate matter in South San Francisco Bay. An unusual flow event was recorded by these instruments during March 8-11, 1995. A 3-D numerical model was implemented which reproduced, qualitatively, the unusual observations and supported the hypothesis that the unusual flow event was caused by a combination of wind driven circulation and weak neap tides.