Genesis and Decay of Mesoscale Baroclinic Eddies in the Seasonally Ice-Covered Interior Arctic Ocean

Type Article
Date 2021-01
Language English
Author(s) Meneghello Gianluca1, Marshall John1, Lique CamilleORCID2, Isachsen Pål Erik3, 4, Doddridge Edward1, 5, Campin Jean-Michel1, Regan Heather2, Talandier Claude6
Affiliation(s) 1 : Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
2 : Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale, IUEM, Brest, France
3 : University of Oslo, Oslo, Norway
4 : Norwegian Meteorological Institute, Oslo, Norway
5 : Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
6 : Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale, IUEM, Brest, France
Source Journal Of Physical Oceanography (0022-3670) (American Meteorological Society), 2021-01 , Vol. 51 , N. 1 , P. 115-129
DOI 10.1175/JPO-D-20-0054.1
WOS© Times Cited 2
Keyword(s) Arctic, Baroclinic flows, Eddies, Ocean circulation, In situ oceanic observations, Quasigeostrophic models
Abstract

Observations of ocean currents in the Arctic interior show a curious, and hitherto unexplained, vertical and temporal distribution of mesoscale activity. A marked seasonal cycle is found close to the surface: strong eddy activity during summer, observed from both satellites and moorings, is followed by very quiet winters. In contrast, subsurface eddies persist all year long within the deeper halocline and below. Informed by baroclinic instability analysis, we explore the origin and evolution of mesoscale eddies in the seasonally ice-covered interior Arctic Ocean. We find that the surface seasonal cycle is controlled by friction with sea ice, dissipating existing eddies and preventing the growth of new ones. In contrast, subsurface eddies, enabled by interior potential vorticity gradients and shielded by a strong stratification at a depth of approximately 50 m, can grow independently of the presence of sea ice. A high-resolution pan-Arctic ocean model confirms that the interior Arctic basin is baroclinically unstable all year long at depth. We address possible implications for the transport of water masses between the margins and the interior of the Arctic basin, and for climate models’ ability to capture the fundamental difference in mesoscale activity between ice-covered and ice-free regions.

Full Text
File Pages Size Access
Publisher's official version 15 3 MB Open access
Supplementary Materials 90 MB Open access
Top of the page

How to cite 

Meneghello Gianluca, Marshall John, Lique Camille, Isachsen Pål Erik, Doddridge Edward, Campin Jean-Michel, Regan Heather, Talandier Claude (2021). Genesis and Decay of Mesoscale Baroclinic Eddies in the Seasonally Ice-Covered Interior Arctic Ocean. Journal Of Physical Oceanography, 51(1), 115-129. Publisher's official version : https://doi.org/10.1175/JPO-D-20-0054.1 , Open Access version : https://archimer.ifremer.fr/doc/00665/77743/