EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Deep Ocean Circulation in the Subpolar North Atlantic Observed by Acoustically-tracked Floats

Sijia Zou1, Amy Bower2, M. Susan Lozier3, and Heather Furey2
Sijia Zou et al.
  • 1State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China (
  • 2Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
  • 3School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA

As part of the Overturning in the Subpolar North Atlantic Program, 122 acoustically-tracked subsurface floats were deployed at 1800-2800 dbar to understand the deep ocean circulation in the subpolar North Atlantic. Gridded mean velocity and eddy kinetic energy (EKE) maps have been constructed using velocity vectors derived from the floats. The mean velocity field reveals a relatively strong deep boundary current around Greenland and in the Labrador Sea, with a weaker deep boundary current over the eastern flank of the Reykjanes Ridge, and near-zero mean flow over the western flank, implying a discontinuous deep boundary current across the subpolar basin. Over most of the subpolar basin, deep EKE resembles that at surface, albeit with smaller magnitudes. A surprising finding about deep EKE is an elevated EKE band east of Greenland. This high EKE band is possibly attributed to the combined influence from propagating Denmark Strait Overflow Cyclones, variability of the wind-driven recirculation offshore of southeast Greenland, and/or topographic waves. The float-based flow fields constructed in this study provide an unprecedented view on the kinematic properties of the large-scale deep circulation in the subpolar North Atlantic.

How to cite: Zou, S., Bower, A., Lozier, M. S., and Furey, H.: Deep Ocean Circulation in the Subpolar North Atlantic Observed by Acoustically-tracked Floats, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-1821,, 2023.