Didwischus, Sven-Helge, Brandt, Peter and Greatbatch, Richard John (2012) Atlantic Equatorial Deep Jets. [Talk] In: Tropical Atlantic Variability Meeting, PIRATA-17 Meeting . , 10.09.-15.09.2012, Kiel .

Preview

Slideshow 120911_TAV_EDJ_shd.pdf Download (2MB) | Preview

Abstract

The Equatorial Deep Jets (EDJ) are a dominant signal in the deep Atlantic at the equator. EDJs are vertical alternating zonal currents with a vertical wavelength of only a few hundred meters. They are found from below the Equatorial Undercurrent down to about 2500m. They were also observed in the Pacific and Indian Ocean. The EDJs are focused on the equator and have a meridional extent of about 1.5°S to 1.5°N. In the Atlantic, EDJs oscillate at a period of about 4.5 years as could be shown by analyzing different datasets including CTD, moored velocity and Argo drift data. Here, we use mooring data, at 23°W, cross-equatorial sections, at 10°, 23° and 35°W, and Argo float data to analyze the space-time structure of the deep jets. The mooring data and the ship sections were decomposed into baroclinic normal modes. These decompositions show energy maxima in a range of the 14th to 21st baroclinic mode at 23°W for both datasets that could be associated with the EDJs. The meridional structure of the 17th baroclinic mode derived from the ship sections is comparable to the meridional structure of a 4.5 year harmonic cycle derived from the Argo float data corresponding to 1000m.

Actions (login required)

View Item