The East Pacific Rise current: Topographic enhancement of the interior flow in the South Pacific Ocean

Citation:
Zilberman, NV, Roemmich DH, Gille ST.  2017.  The East Pacific Rise current: Topographic enhancement of the interior flow in the South Pacific Ocean. Geophysical Research Letters. 44:277-285.

Date Published:

2017/01

Keywords:

Argo data, budget, circulation, East Pacific Rise, intermediate, Meridional circulation, ocean interior, Sverdrup balance, topographic steering, variability, velocities

Abstract:

Observations of absolute velocity based on Argo float profiles and trajectories in the ocean interior show evidence for an equatorward current, the East Pacific Rise current, between 42 degrees S and 30 degrees S, along the western flank of the East Pacific Rise. The East Pacific Rise current carries predominantly intermediate water masses, including Subantarctic Mode Water and Antarctic Intermediate Water, and deeper waters, from the southern edge of the subtropical gyre toward the Equator. The 2004 to 2014 mean East Pacific Rise current transport extrapolated through the 0-2600m depth range is 8.11.6 sverdrup (Sv) (1 Sv=10(6)m(3)s(-1)), consistent with a wind-driven interior transport influenced by the East Pacific Rise topography. While deep ocean mixing and geothermal heating can both create pressure gradients that support geostrophic flows in the deep ocean, this study indicates that about half of the East Pacific Rise current transport is associated with topographic steering of the deep flow over the East Pacific Rise.

Notes:

n/a

Website

DOI:

10.1002/2016gl069039