Earth Simulator Center

ESC seminar No. 51

The South Indian subtropical countercurrent

Date

Apr. 10 (Fri.), 2009, 13:30-14:30

Place

Seminar Room. 1F, Earth Simulator Research Building, YES, JAMSTEC

Speaker

Dr. Ryo Furue (IPRC University of Hawaii)

Language

English

Abstract

In the North and South Pacific and in the South Indian, there exist near-surface currents flowing eastward in the equatorward half of the subtropical gyre, where the Sverdrup flow is generally westward. They are generally called subtropical countercurrents (SICCs). In the South Indian Ocean, SICCs form a broad flow impinging onto the coast of Australia. The southern-most branch of this flow is recently discovered to be narrow and strong and is called the South Indian countercurrent (SICC). In the present study, we describe the three-dimensional structure of the broad eastward flow and the SICC in Argo climatology and ocean-only numerical models.

The STCCs are confined to top ~200m, below which there are westward currents, which seem to form a baroclinic pair with the surface eastward currents. The SICC is deeper and stronger than the broad eastward flow to the north. The deep flow below the SICC seem to come from a westward current along the south coast of Australia. On the basis of these results, we propose hypotheses to explain the dynamics of the SICC and show some preliminary results of simple layer models to test the hypotheses.

Contact

Wataru Ohfuchi
Earth Simulator Center
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