Landfast Ice Controls on Turbulence in Antarctic Coastal Seas

Knowledge of the ocean surface layer beneath Antarctic landfast ice is sparse. In this article surface layer turbulent and fine structure are quantified with and without landfast ice at the same West Antarctic Peninsula location. Landfast ice reduced turbulence levels locally to an order of magnitud...

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Bibliographic Details
Published in:Journal of Geophysical Research: Oceans
Main Authors: Inall, Mark E., Brearley, J. Alexander, Henley, Sian F., Fraser, Alexander D., Reed, Sarah
Format: Article in Journal/Newspaper
Language:English
Published: 2022
Subjects:
Online Access:https://pure.uhi.ac.uk/en/publications/f95f0ff1-01d0-4648-88ed-9fe08863a023
https://doi.org/10.1029/2021JC017963
https://pureadmin.uhi.ac.uk/ws/files/17316641/JGR_Oceans_2021_Inall_Landfast_Ice_Controls_on_Turbulence_in_Antarctic_Coastal_Seas.pdf
https://onlinelibrary.wiley.com/doi/10.1029/2021JC017963
Description
Summary:Knowledge of the ocean surface layer beneath Antarctic landfast ice is sparse. In this article surface layer turbulent and fine structure are quantified with and without landfast ice at the same West Antarctic Peninsula location. Landfast ice reduced turbulence levels locally to an order of magnitude less than ice-free values, and near-inertial energy and sub-inertial tidal energy levels to less than half their ice-free values. Vertical turbulent heat and nutrient fluxes were, respectively, 6 and 10 times greater than previously estimated. Under-ice tidal energy dissipation over the entire Antarctic continental shelf due to seasonal landfast ice cover is estimated to be between 788 MW to ∼6 GW. The total rate of wind-generated turbulence in the surface ocean is greatly reduced by the presence of seasonal landfast ice to an average of 14% of the ice-free value, but with large sectoral variations. Counter-intuitively, however, tides and wind contribute approximately equally to the turbulent kinetic energy budget of the upper ocean between the Antarctic coastline and the maximal landfast ice extent, with large sectoral variations, attributed to geographic variations in the strength of the barotropic tide