Forcing of the Atlantic Equatorial Deep Jets derived from Observations.

Claus, Martin , Greatbatch, Richard John , Brandt, Peter and Toole, John M. (2016) Forcing of the Atlantic Equatorial Deep Jets derived from Observations. Open Access Journal of Physical Oceanography, 46 (12). pp. 3549-3562. DOI 10.1175/JPO-D-16-0140.1.

[thumbnail of claus_etal16.pdf]
Preview
Text
claus_etal16.pdf - Published Version
Available under License Creative Commons: Attribution 4.0.

Download (1MB) | Preview

Supplementary data:

Abstract

The Equatorial Deep Jets (EDJs) are an ubiquitous feature of the equatorial oceans; in the Atlantic Ocean, they are the dominant mode of interannual variability of the zonal flow at intermediate depth. On the basis of more than 10 years of moored observations of zonal velocity at 23°W, the vertically propagating EDJs are best described as superimposed oscillations of the 13th to the 23th baroclinic modes with a dominant oscillation period for all modes of 1650 days. This period is close to the resonance period of the respective gravest equatorial basin mode for the dominant vertical modes 16 and 17. It is argued that since the equatorial basin mode is composed of linear equatorial waves, a linear reduced gravity model can be employed for each baroclinic mode, driven by spatially homogeneous zonal forcing oscillating with the EDJ period. The fit of the model solutions to observations at 23°W yields a basin wide reconstruction of the EDJs and the associated vertical structure of their forcing. From the resulting vertical profile of mean power input and vertical energy flux on the equator, it follows that the EDJs are locally maintained over a considerable depth range, from 500-2500 m, with the maximum power input and vertical energy flux at 1300 m. The strong dissipation closely ties the apparent vertical propagation of energy to the vertical distribution of power input and, together with the EDJs’ prevailing downward phase propagation, require the phase of the forcing of the EDJs to propagate downward.

Document Type: Article
Funder compliance: info:eu-repo/grantAgreement/EC/FP7/603521
Research affiliation: OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-TM Theory and Modeling
OceanRep > GEOMAR > FB1 Ocean Circulation and Climate Dynamics > FB1-PO Physical Oceanography
OceanRep > SFB 754
Kiel University
Refereed: Yes
Open Access Journal?: No
Publisher: AMS (American Meteorological Society)
Projects: MODINI, SFB754, RACE, SACUS, PREFACE, PIRATA
Expeditions/Models/Experiments:
Date Deposited: 06 Sep 2016 07:21
Last Modified: 18 May 2021 12:27
URI: https://oceanrep.geomar.de/id/eprint/33716

Actions (login required)

View Item View Item