Diabaté, Samuel Tiéfolo and Swingedouw, Didier and Hirschi, Joël J.-M. and Duchez, Aurélie and Leadbitter, Philip J. and Haigh, Ivan D. and McCarthy, Gerard (2021) Western boundary circulation and coastal sea-level variability in Northern Hemisphere oceans. Ocean Science, 17. pp. 1449-1471. ISSN 1812-0784

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Abstract

The northwest basins of the Atlantic and Pacific oceans are regions of intense western boundary currents (WBCs): the Gulf Stream and the Kuroshio. The variability of these poleward currents and their extensions in the open ocean is of major importance to the climate system. It is largely dominated by in-phase meridional shifts downstream of the points at which they separate from the coast. Tide gauges on the adjacent coastlines have measured the inshore sea level for many decades and provide a unique window on the past of the oceanic circulation. The relationship between coastal sea level and the variability of the western boundary currents has been previously studied in each basin separately, but comparison between the two basins is missing. Here we show for each basin that the inshore sea level upstream of the separation points is in sustained agreement with the meridional shifts of the western boundary current extension over the period studied, i.e. the past 7 (5) decades in the Atlantic (Pacific). Decomposition of the coastal sea level into principal components allows us to discriminate this variability in the upstream sea level from other sources of variability such as the influence of large meanders in the Pacific. Our result extends previous findings limited to the altimetry era and suggests that prediction of inshore sea-level changes could be improved by the inclusion of meridional shifts of the western boundary current extensions as predictors. Long-duration tide gauges, such as Key West, Fernandina Beach or Hosojima, could be used as proxies for the past meridional shifts of the western boundary current extensions

Item Type:	Article
Additional Information:	This work is distributed under the https://creativecommons.org/licenses/by/4.0/. Diabaté, S. T., Swingedouw, D., Hirschi, J. J.-M., Duchez, A., Leadbitter, P. J., Haigh, I. D., and McCarthy, G. D.: Western boundary circulation and coastal sea-level variability in Northern Hemisphere oceans, Ocean Sci., 17, 1449–1471, https://doi.org/10.5194/os-17-1449-2021, 2021.
Keywords:	Atlantic Meridional Overturning Circulation (AMOC); Western boundary circulation; coastal sea-level variability; Northern Hemisphere; oceans;
Academic Unit:	Faculty of Social Sciences > Geography Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS
Item ID:	14988
Identification Number:	https://doi.org/10.5194/os-17-1449-2021
Depositing User:	Gerard McCarthy
Date Deposited:	08 Nov 2021 14:25
Journal or Publication Title:	Ocean Science
Publisher:	European Geosciences Union
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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