gyre doesn't have to mean gyre
'I don't know what you mean by "gyre",' Alice said. Humpty Dumpty: 'Of course you don't — till I tell you. I meant 'there's a nice little drift for you!' 'But "gyre" doesn't mean "a nice little drift",' Alice objected, 'it's meant circular for several thousand years.' 'When I use a word,' Humpty Dumpty said, 'it means just what I choose it to mean — neither more nor less.' I saw a partial full ice gyre once on an oblique low resolution 40-year youtube
A pity you didn't take note of the date.
there's a distinction between an ocean gyre and an ice drift gyre.
Right. Many oceanographic writings avoid ice motion, or the lack of it, that we see in buoy tracks and satellite time series. They are talking about inferred deep water currents and a large pool of slightly reduced salinity (confusingly called "fresh water"). There is
not a single drop of fresh water anywhere in or under the central Beaufort Sea. T
he 28-frame gif below collects some of the silliness surrounding 'Beaufort Gyre' depictions -- it's whatever and wherever you want it to be! Publishing garbage diagrams undermines public trust in overall climate science -- we cannot afford that.
https://sci-hub.se/https://doi.org/10.1029/2018JC014379 rare serious treatment
https://cpom.org.uk/glimpsing-under-the-ice-measuring-the-ice-covered-arctic-ocean-from-space/OsiSaf/GFS have shown over and over that when the wind does not blow, the ice does not move. That means no surface currents of any significance (Nares, Fram, Yermak, FJL, Bering excepted). Ice motion in the central Arctic Ocean is entirely wind-driven.
That's a problem for the 'Beaufort Ice Gyre' because the 'Beaufort High' is rarely where it needs to be. Often the high is bounded on its south by land, causing strong winds up the Alaskan coast that make ice drift rapidly west there (before breaking apart melting out in the Chukchi as 'Big Block' did in 2016). The problem is the opposite side of the 'Beaufort High' is often elsewhere, failing to move the pack ice in a gyre (Fig.2).
The Polarstern measured currents, tides, turbulence and eddies under the ice during their long drift but has not released any data. The TransPolar Drift, while highly variable and largely unpredictable, is not as frothy a subject as
non-existent Beaufort Ice Gyre but might better be called the CircumPolar Drift because in the last decades, ice has rarely drifted over the north pole ('trans' means across) as it did during the Mosaic year.
CMEMS, our main online source for oceanographic time series, provides very detained views of Arctic Ocean ice motion from 01 Nov 2018 into late Dec 2020 with its daily neXtSIM product. At some point, that product will be extended much farther back in the satellite record (that's used for daily assimilations).
For now, it allows complete coverage of the Mosaic year, as well as regions elsewhere in the Arctic. However file size is an issue for the full 781 days, especially for the 2.1 GB gif. A small preliminary version of the western sea ice motion is attached below.
Although neXtSIM overlaps (ie extends) Polarstern 6-hourly bow radar scale, the latter is confined to its drift track. The current persistent high associated with the anti-cyclone has allowed an extraordinary and continuing basin-wide view of heat-leaking leads via Suomi Band 15 infrared.
The attached gif shows the full range of scale zooms for the available resolution. While ice fractures aren't really fractal in the mathematical sense, new leads become visible the larger the scale -- the Beaufort ice shown has had a surprisingly extensive history of fracture. These continue to leak heat more rapidly than their matrix until such time as the thicknesses more or less equalize.
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