Affiliation:
1. Department of Marine Sciences University of Gothenburg Gothenburg Sweden
2. Scripps Institution of Oceanography University of California San Diego La Jolla CA USA
3. Indian Institute of Technology Madras Chennai India
Abstract
AbstractWe analyze 15‐year of observational data and a 5‐year Southern Ocean model simulation to quantify the transformation rates of Circumpolar Deep Water (CDW) and the associated heat loss to the surface. This study finds that over the continental shelves of East Antarctica and the Weddell and Ross Seas, surface buoyancy fluxes transform ∼4.4 Sv of surface waters into CDW, providing a path for CDW to lose heat to the surface. In addition, ∼6.6 Sv of CDW are mixed with surface waters in the Weddell and Ross subpolar gyres. In contrast, enhanced stratification inhibits the outcropping of CDW isopycnals, reducing their transformation rates by a factor of ∼8 over the continental shelf and by a factor of ∼3 over the deeper ocean in the Amundsen and Bellingshausen Seas. The CDW retains its offshore warm properties as it intrudes over the continental shelves, resulting in elevated bottom temperatures there. This analysis demonstrates the importance of processes in subpolar gyres to erode CDW and to facilitate further transformation on the continental shelves, significantly reducing the heat able to access ice shelf fronts. This sheltering effect is strongest in the western Weddell Sea and tends to diminish toward the east, which helps explain the large zonal differences in continental‐shelf bottom temperatures and the melt rates of Antarctic ice shelves.
Funder
National Centre for Polar and Ocean Research, Ministry of Earth Sciences
Horizon 2020 Framework Programme
National Aeronautics and Space Administration
National Science Foundation
Publisher
American Geophysical Union (AGU)
Subject
Earth and Planetary Sciences (miscellaneous),Space and Planetary Science,Geochemistry and Petrology,Geophysics,Oceanography
Cited by
1 articles.
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