California Current - Physical Properties

Physical Properties

The Southern California Bight is a sub-region of the California Current and has unique physical properties. Upwelling is fairly weak in the California Bight and Smith and Eppley (1982) stated that the 16-year average for primary production was 0.402 grams Carbon/(meter-squared x day),or approximately 150 grams carbon/(meter-squared x year). Further, Smith and Eppley (1982) found that the highest daily rates of temperature decrease were correlated with the maximum amount of upwelling (Mann and Lazier, 2006). Digiacomo and Holt (2001) used satellite images to study the mesoscale and sub-mesoscale eddies in the Southern California Bight. Their work showed that all eddies were less than 50 km in diameter and 70% of all eddies measured less than 10 km (Mann and Lazier, 2006). The eddies appeared to be caused mostly by topography (particularly islands), wind, and instabilities in the current. The location of these eddies was mainly between the California Current (flowing toward the equator) and the coastline (Mann and Lazier, 2006). The majority of these eddies were cyclonic and had the ability to induce the upwelling of nutrient-rich water. Small scale topographic features such as headlands have been shown to cause substantial effects on the population dynamics of benthic invertebrates, such a change in the settlement patterns of crabs and sea urchin (Mann and Lazier, 2006).