SEDIMENT-TRANSPORT EVENTS ON THE NORTHERN CALIFORNIA CONTINENTAL-SHELF DURING THE 1990-1991 STRESS EXPERIMENT

Measurements of currents and light transmission were made at bottom tr ipods and moorings arrayed across the northern California continental shelf along the Coastal Ocean Dynamics Experiment (CODE) ''C'' transec t as part of the 1990-1991 Sediment Transport Events on Shelves and Sl opes (STRESS) experiment. In combination with meteorological and wave data from the National Data Buoy Center Buoy 46013, these measurements provide information about the physical forcing and resultant resuspen sion and transport of bottom material between 21 November and 8 March. Sixteen events were identified in the wave, wind and current-meter re cords for this period. Only two were local storms with southerly winds , but they caused about half of the seasonal net transport. Seven were swell events that combined long-period waves generated by distant sto rms with local currents. At the 90-m site, swells interacted with the mean northward flow to produce northward transport. During six norther ly wind events, upwelling-favorable winds often were sufficient to slo w or reverse the mean northward flow and thus caused southward transpo rt. A single current event, which produced moderate southward transpor t, was observed at the 130-m site. Net transport during the winter exp eriment was offshore at all sites, northward at the inner- and mid-she lf sites, but southward at the outer-shelf site. The results suggest t hat local storms with southerly winds may dominate seasonal transport, as on the Washington shelf, but significant transport also can occur during fair weather and during periods of northerly winds.