Potential vorticity dynamics of the arctic halocline
Citable URI
https://hdl.handle.net/1912/26683As published
https://doi.org/10.1175/JPO-D-20-0056.1DOI
10.1175/JPO-D-20-0056.1Keyword
Eddies; Ekman pumping/transport; Ocean circulation; Ocean dynamics; Potential vorticity; Shallow-water equationsAbstract
An idealized two-layer shallow water model is applied to the study of the dynamics of the Arctic Ocean halocline. The model is forced by a surface stress distribution reflective of the observed wind stress pattern and ice motion and by an inflow representing the flow of Pacific Water through Bering Strait. The model reproduces the main elements of the halocline circulation: an anticyclonic Beaufort Gyre in the western basin (representing the Canada Basin), a cyclonic circulation in the eastern basin (representing the Eurasian Basin), and a Transpolar Drift between the two gyres directed from the upwind side of the basin to the downwind side of the basin. Analysis of the potential vorticity budget shows a basin-averaged balance primarily between potential vorticity input at the surface and dissipation at the lateral boundaries. However, advection is a leading-order term not only within the anticyclonic and cyclonic gyres but also between the gyres. This means that the eastern and western basins are dynamically connected through the advection of potential vorticity. Both eddy and mean fluxes play a role in connecting the regions of potential vorticity input at the surface with the opposite gyre and with the viscous boundary layers. These conclusions are based on a series of model runs in which forcing, topography, straits, and the Coriolis parameter were varied.
Description
Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(9), (2020): 2491-2506, doi:10.1175/JPO-D-20-0056.1.
Collections
Suggested Citation
Spall, M. (2020). Potential vorticity dynamics of the arctic halocline. Journal of Physical Oceanography, 50(9), 2491-2506.Related items
Showing items related by title, author, creator and subject.
-
Formation of intrathermocline eddies at ocean fronts by wind-driven destruction of potential vorticity
Thomas, Leif N. (2008-02)A mechanism for the generation of intrathermocline eddies (ITEs) at wind-forced fronts is examined using a high resolution numerical simulation. Favorable conditions for ITE formation result at fronts forced by “down-front” ... -
Temporal dynamics of Prochlorococcus cells with the potential for nitrate assimilation in the subtropical Atlantic and Pacific oceans
Berube, Paul M.; Coe, Allison; Roggensack, Sara E.; Chisholm, Sallie W. (Elsevier B.V., 2015-10-30) -
Potential vorticity constraint on the flow between two basins
Yang, Jiayan; Price, James F. (American Meteorological Society, 2007-09)This paper examines the role of potential vorticity (PV) balance in source- and sink-driven flows between two basins. As shown in previous studies, PV advection into a basin, say a positive PV advection, requires a negative ...