Seabed Drifter Movement in San Diego Bay and Adjacent Waters.
NAVAL UNDERSEA CENTER SAN DIEGO CALIF
Pagination or Media Count:
A study was made on net bottom water movement which effects the flushing of solid waste, sediment transport and circulation of the San Diego estuarine system. 500 Drifters were released in the bay and adjacent ocean waters to delineate bottom flow patterns. Contrary to expectations, off coast drifter results 31 recovery showed a persistent north moving bottom current with shallow near coast drift distances between 4 and 25 kilometers. This could affect residual sewage sludge deposited near the San Diego municipal outfall but probably not the warmer effluent waters. This nearshore north moving bottom current appears to cause a net bottom water inflow into the main San Diego Bay channel 44 recovery complicating the flushing of bottom debris. In the open bay a reverse trend was observed from the 16 of the drifters recovered. At the head of the estuary evaporative densification is believed to occur, with the heavier water sinking and moving outward, toward the estuary mouth, resulting in an area of opposing bottom water currents. In this area an electric power plant takes in an average 150 million gallons of cooling water daily which, discharged as warm surface water, is suggested as the surface divergence mode required to reconcile the observed flow. With 3 San Diego Bay electric power plants utilizing more than 5 of the maximum tidal prism for cooling purposes, this flow may play a major role in overall bay circulation and requires quantitative investigation.
- Physical and Dynamic Oceanography
- Water Pollution and Control