Surface circulation and fronts of the South Pacific Ocean, east of 120°W

Authors

  • Alexis Chaigneau,

    1. Centro de Investigación Oceanográfica en el Pacífico Sur-Oriental (COPAS) and Programa Regional de Oceanografía Física y Clima (PROFC), Universidad de Concepción, Concepción, Chile
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  • Oscar Pizarro

    1. Departamento de Geofísica, Centro de Investigación Oceanográfica en el Pacífico Sur-Oriental (COPAS), and Programa Regional de Oceanografía Física y Clima (PROFC), Universidad de Concepción, Concepción, Chile
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Abstract

[1] The South Pacific surface circulation east of 120°W is studied, using satellite tracked drifters from 1979–2004. The major currents of this region are described such as the Antarctic Circumpolar, the South Pacific, the Chile-Peru and the Cape Horn Currents. We suggest the presence of a branch, exiting from the ACC between 100–120°W, and transporting subantarctic surface water toward lower latitudes. We also show the existence of an anticyclonic recirculation cell north of 35°S. Finally, based on hydrographic sections, we show that in the eastern South Pacific the core of the Subtropical front corresponds to the 14°C isotherm at 150 m depths and to the 2.7 m of dynamic height relative to 3000 m. The Subantarctic front is located by maximum temperature gradients in the range 3–8°C at 100–400 m depth.

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