Observed Spatioâ€Temporal Variability of the Eddyâ€Sea Ice Interactions in the Arctic Basin

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Cassianides, Angélina, Lique, Camille, Tréguier, Anneâ€Marie, Meneghello, Gianluca, De Marez, Charly
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2023
• Subjects: Earth and Planetary Sciences (miscellaneous); Space and Planetary Science; Geochemistry and Petrology; Geophysics; Oceanography; Arctic; Arctic Basin; ice pack; Sea ice
• Online Access: https://doi.org/10.1029/2022jc019469

In the Arctic Basin, the ocean dynamics at mesoscale and submesoscale under sea ice are poorly quantified and understood. Here, we analyze comprehensive data sets from Ice Tethered Profilers and moorings from the Beaufort Gyre Observing System spanning the period 2004–2019 in order to characterize the space and time variations of the (sub)mesoscale flow. In seasonally ice-covered regions, the dynamics in the surface layer is largely determined by the presence of sea ice, with an increased eddy kinetic energy and numerous eddies in summer. Beyond these regions, the influence of the sea ice conditions on the first order dynamics is less clear. A wavenumber spectra analysis of observations at the surface and at depth under the sea ice pack reveals that a large variety of regimes can be found, independently of the time and space variations of the sea ice conditions. Focusing on a census of individual eddies, and their potential signature in sea ice, we found that around 500 eddies can be detected in the subsurface layer over 2004–2019, including both submesoscale (radius between 3 and 10 km) and mesoscale (up to 80 km) structures. Based on simple scaling calculations, we quantify the dynamical or thermodynamical signature that these eddies may imprint at the surface. While they do not induce any significant heat flux and subsequent sea ice melt, subsurface eddies can induce a dynamic height anomaly of the order of a few centimetres, resulting into a surface vorticity anomaly strong enough to impact sea ice locally. © 2023. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. This work was supported by the French ANR through the project ImMEDIAT (Grant ANR-18-CE01-0010), and a PhD studentship from Ifremer. G. M. was supported by NASA Grant 80NSSC21K0557. C.D.M. was supported by NASA Grant 80NSSC20K1140. We thank Carolina Dufour for a careful edit of ...