Submesoscale Sea Ice-Ocean Interactions in Marginal Ice Zones

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Manucharyan, Georgy E., Thompson, Andrew F.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2017
• Subjects: Sea ice melt; Submesoscale eddies; ocean heat flux; marginal ice zone; melt water fronts; localized upwelling; Arctic Ocean; Global warming; Sea ice
• Online Access: https://doi.org/10.1002/2017JC012895

Signatures of ocean eddies, fronts, and filaments are commonly observed within marginal ice zones (MIZs) from satellite images of sea ice concentration, and in situ observations via ice-tethered profilers or underice gliders. However, localized and intermittent sea ice heating and advection by ocean eddies are currently not accounted for in climate models and may contribute to their biases and errors in sea ice forecasts. Here, we explore mechanical sea ice interactions with underlying submesoscale ocean turbulence. We demonstrate that the release of potential energy stored in meltwater fronts can lead to energetic submesoscale motions along MIZs with spatial scalesO(10 km) and Rossby numbersO(1). In low-wind conditions, cyclonic eddies and filaments efficiently trap the sea ice and advect it over warmer surface ocean waters where it can effectively melt. The horizontal eddy diffusivity of sea ice mass and heat across the MIZ can reachO(200 m2s−1). Submesoscale ocean variability also induces large vertical velocities (order 10 m d−1) that can bring relatively warm subsurface waters into the mixed layer. The ocean-sea ice heat fluxes are localized over cyclonic eddies and filaments reaching about 100 W m−2. We speculate that these submesoscale-driven intermittent fluxes of heat and sea ice can contribute to the seasonal evolution of MIZs. With the continuing global warming and sea ice thickness reduction in the Arctic Ocean, submesoscale sea ice-ocean processes are expected to become increasingly prominent. © 2017 American Geophysical Union. Received 17 MAR 2017; Accepted 25 OCT 2017; Accepted article online 2 NOV 2017; Published online 5 DEC 2017. All information necessary to reproduce the numerical experiments is included in the manuscript; MITgcm name lists and configuration files could be found at http://web.gps.caltech.edu/~andrewt/publications/MIZconfigFiles.tar.gz. G.E.M. and A.F.T. gratefully acknowledge support from the Stanback Postdoctoral Fellowship Fund and the Davidow Discovery Fund at Caltech. ...