Publication Date:
2022-05-25
Description:
© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geophysical Research Letters 45 (2018): 1923–1929, doi:10.1002/2017GL076662.
Description:
Recent evidence from mooring data in the equatorial Atlantic reveals that semiannual and longer time scale ocean current variability is close to being resonant with equatorial basin modes. Here we show that intraseasonal variability, with time scales of tens of days, provides the energy to maintain these resonant basin modes against dissipation. The mechanism is analogous to that by which storm systems in the atmosphere act to maintain the atmospheric jet stream. We demonstrate the mechanism using an idealized model setup that exhibits equatorial deep jets. The results are supported by direct analysis of available mooring data from the equatorial Atlantic Ocean covering a depth range of several thousand meters. The analysis of the mooring data suggests that the same mechanism also helps maintain the seasonal variability.
Description:
This study was supported by the Deutsche Forschungsgemeinschaft as part of the Sonderforschungsbereich 754 “Climate‐Biogeochemistry Interactions in the Tropical Ocean” and through several research cruises with RV Meteor, RV Maria S. Merian, and RV L'Atalante, by the German Federal Ministry of Education and Research as part of the cooperative projects RACE (03F0605B), SACUS (03G0837A), and MiKlip2 (ATMOS‐MODINI; 01LP1517D) and by the European Union 7th Framework Programme (FP7 2007–2013) under grant agreement 603521 PREFACE project. Support for the moored observations was additionally provided by the U.S. National Science Foundation.
Keywords:
Equatorial deep jets
;
Seasonal cycle
;
Momentum flux convergence
;
Tropical instability waves
;
Equatorial basin mode resonance
Repository Name:
Woods Hole Open Access Server
Type:
Article
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