Neven:
As soon as the winds turn, those gaps will close presto."
John33:
...the only forcings on it are barometric changes and tides" and "The winds are not so different from previous years"
& binntho:
Everything that is happening in the arctic can be explained with reference to increases in temperature..."
All, please let's keep an open mind.
This 2018 paper by McFarlin et al. (
https://www.pnas.org/content/115/25/6357 ) came up with a new interpretation of the early Holocene heat anomaly NW of Greenland. They suggested summer temperatures 3-5 C higher than present, mainly driven by astronomical forcing.
This 2007 paper by Nørgaard-Pedersen et al. (
https://doi.org/10.1029/2006PA001283 ) documented two periods in the past, when subarctic foraminifers were abundant in ocean sediments NW of Greenland (Lincoln Sea). Isotopic substage 5a and LIG (5e) also known as the Eemian, may be good analogues for a soon to come "Giant Gap" N of Greenland.
Most likely interpretation is that polynias NW and NE of Greenland "merged" N of Greenland and a direct E- or W-going current of Atlantic origin existed N of Greenland. Several drivers of this W-bound current have been suggested:
1) Offshore (S-ly) winds off the Greenland Icesheet
2) Tides
3) Temperatures
Several additional factors may be at play here:
4) An over-abundance of Atlantic hurricanes may contribute to extreme S-ly winds over Greenland over the next few months
5) The Lomonosov Ridge or the Cape Morris Jesup Rise may play key roles in the rearrangement of current Arctic currents
6) The warming of Laptev and other Siberian Seas may have "forced" the Atlantic current in a W-ly direction
However, the physics involved have not yet been dealt with, and this may require a separate thread in order to not stir this one up. I must admit that I "miss the old days" when one of Neven's ASIB entries led to a broad, informed discussion at a fairly low pace for several days or weeks. At that time, contributors were allowed to think between their posts.
In order to make the connection to our immediate present and near future calamities, this recent paper based on a new version of the Hadley Centre model ( HadGEM3 ) resolving meltponds on the Arctic sea ice (
https://www.sciencedaily.com/releases/2020/08/200810113216.htm ) points to an early ice-free Arctic Ocean already in 2035. Since it is behind a paywall, and not all details in the marine part of the model spectrum are freely available, it would be nice to get a hint of what the currents in the model will look like in about 15 years.