Summary of Abstract Submission

Abstract Submission No. IO50-04-0049PresentationPoster

WHAT DECIDES THE ZONAL SCALE OF BUOYANCY FORCED EASTERN BOUNDARY CURRENTS IN THE ABSENCE OF WIND FORCING?

Suyash Bire*1, Christopher Wolfe1

1 Stony Brook University, USA

ABSTRACT :

Observations of eastern boundary currents (EBC) in all the major ocean basins show that they are narrow (~20-30km), equator-ward flowing slow currents (~10-20cm/s) with accompanying poleward undercurrents. In the Pacific and Atlantic basins, upwelling favorable winds along the eastern boundaries tend to decide the direction and scale of their respective EBCs. However, in the South Indian Ocean, where the upwelling favorable winds are weak, the Leeuwin current flows poleward at the surface with an equator-ward undercurrent. We simulated this current in MITGCM using an idealized geometry forced by a restoring buoyancy at the sea surface. We then carried out sensitivity analyses by changing the values of vertical and horizontal diffusion, vertical and horizontal viscosity, and by turning beta on and off. We then compared our results to those obtained from the linear continuously stratified model from McCreary et al 1986. Our preliminary studies show that the width of this current is set by the amount of vertical viscosity and diffusion specified in the model.