Sediment transport

Large image of sediment transport

In early January 1997 an extreme storm with strong winds and rain induced fast, organized currents in the ocean off northern California. The evolution of an eddy off the Eel River, just north of Cape Mendocino, California, is seen in modeled surface salinity (color contours) and surface velocity (arrows). The eddy develops as the severe storm passes over, causing a rotation in the wind stress field. Intense precipitation from the storm floods the Eel River leading to a salinity signature of the Eel River in the adjacent coastal waters. Fixed ADCP and mooring locations instrumented by Strata Formation on Margins (STRATAFORM) are indicated with crosses. The ONR-sponsored STRATAFORM is a marine geology observational program aimed at understanding the sedimentary processes associated with flood events. The strong currents received sediment-laden runoff from the Eel River and thus influenced the fate of sediment on the continental shelf. The simulations were used to investigate the mechanisms of the coastal ocean response during winter 1996-1997, and to aid geologists in interpreting the movement of sediments.

The model fields shown were from the interior nest of a series of three model domains. The outermost model was the Naval Research Laboratory’s Pacific West Coast model (PWC), with approximately 9 km horizontal resolution. For these modeling studies, nests of 3 km and 1 km resolution were inserted within the PWC model to focus on the region around Cape Mendocino. All model configurations utilized 30 vertical sigma levels. The models were forced by wind stress fields from the Navy Operational Global Atmospheric Prediction System (NOGAPS) and by observed river discharge from the USGS stream gauge.

Sherwood, C. et al. “Sediment dynamics in the Adriatic Sea investigated with coupled models,” Oceanography, 17 (4), 2004 (pdf)

Pullen, J. and J. S. Allen, “Modeling studies of the coastal circulation off northern California: Statistics and patterns of wintertime flow,” Journal of Geophysical Research, 106, 26959-26984, 2001 (pdf)

Pullen, J. and J. S. Allen, “Modeling studies of the coastal circulation off northern California: Shelf response to a major Eel River flood event,” Continental Shelf Research, 20, 2213-2238, 2000 (pdf)