A Numerical Study of Oceanic Circulation in San Juan, Peru. Calibration of Princeton Ocean Model During 1991-2000

ABSTRACT

The Eastern Tropical and Subtropical Pacific, particularly the coastal region of the western South America, is affected by the El Niño Southern Oscillation (ENSO) event. In this work ERS-1 and ERS-2 scatterometer data of wind stress climatology are used to study Ekman pumping/suction and transport in the coastal ocean at 15°S off San Juan, Peru. The Princeton Ocean Model (POM) was run to study oceanic circulation and Ekman dynamics along the Peruvian coast when La Niña (1996-1997) and El Niño (1997-1998) events occur. The model is forced by the wind stress and I use the temperature and salinity are taken from levitus climatology The analysis confirm that when strong El Niño events occur, the meridional wind stress has a dominant role in the intensity of coastal upwelling, the speed of Ekman pumping was nearly six (6) times larger than the normal speed of Ekman suction and offshore Ekman transport nearly doubled.

Keywords:

Coastal upwelling, ekman pumping, humboldt current, offshore ekman transport, onshore-offshore ekman transport, princeton ocean model.