Hydrological aspects in the Peruvian seabed associated with the Cromwell Current Southern Extension (CCSE) between 3° and 7°S

Abstract

To determine seasonal and spatial variability on the seabed in northern Perú during the last 30 years (1980-2009), we studied the temperature and dissolved oxygen between latitudes 3°-7°S. We found a higher latitudinal projection of the dissolved oxygen (DO), greater than 1.0 mL/L in the fall season, bounded by the isotherm of 15 °C at the edge of the platform. This projection would be associated with subsurface flows to the south, which form the Southern Extension of the Cromwell Current (SECC), at depths of 90-180 m. The oxygen would be influenced by the increase or withdrawal of the SECC present in the area. The mean change from 0.7 to 1.3 oxygen values recorded mL/L in summer and 0.8 to 1.6 mL/L in the fall. Paita (5°S) presents average values of 1.0 mL/L in summer and 1.4 mL/L in the fall. The highest DO values are associated with lower latitudes in both seasons; the fall season provides the highest oxygen content associated with a greater intensity of ESCC.