The effect of salinity on density in the California Current system

Abstract

There are some indications that in large measure the density anomaly field of the California Current system (CCS) follows temperature, salinity playing a significantly lesser role. These indications have been used as justification for not taking as extensive salinity as temperature observations in the CCS, as well as for using fixed or prescribed salinity fields in density calculations in dynamic models of the CCS. An extensive data base of temperature-salinity observations from the CCS is used to show that there are noticeable differences between the dynamic height field calculated with and without the inclusion of salinity variations. Hence the distribution of salinity is important in defining the large-scale circulation of the CCS. In particular, owing to the combined effect of temperature and salinity on density, the dynamic height fields show a significant equatorward component along the coast of California and a strong offshore component adjacent to Baja California. Based on these observations, it is concluded that descriptively and dynamically, both temperature and salinity are essential to accurately characterize the large-scale structure of the CCS.