The past winter saw a surprising number of powerful lows cross Barents Sea into Kara Sea, with the north winds behind these gales pulling sea-ice south around Svalbard. The most recent gale took a more traditional route, hooking back west in a retrograde manner and passing right over Svalbard.
The MOSAiC Expedition, in the sea-ice about a third of the way to the Pole from Svalbard, experienced winds of 83 km/hr north of the gale, as the sea-ice accelerated from a nearly stationary drift to a drift of over a kilometer an hour for a while. The bow-radar on the Polarstern showed a lead open and close, but not a great break-up of sea-ice. The sea-ice, which had been showing a slow drift southeast, was jerked west-southwest.
The MOSAiC Expedition, north of all the Barent Sea storms, has seen sea-ice in the Transpolar Drift move about twice as fast as usual. The hook to the southeast was unusual, and perpendicular to the drift the Fram saw, New Years to Mayday, in 1896.
The recent jerk to the west-southwest is more in line with the Fram’s Track. It will be interesting to study the condition of the sea-ice, once the weather clears and the satellite view improves. Currently it looks like the gale tore the sea-ice from the north coast of Svalbard.
What I wonder about is how much the sea-ice was compressed between Svalbard and the MOSAiC expedition. The Polarstern is suppose to head south towards Svalbard to be resupplied, and what they desire for such a journey is leads, and not pressure ridges.
There is an excellent video of part of the Russian icebreaker Kapitan Dranitsyn”s trip south from the MOSAiC site to port, showing how it has to back up and then ram to get through even ordinary sea-ice, yet has a far easier time once it finds leads skimmed with baby-ice.
In all, the journey of the Kapitan Dranitsyn from the MOSAiC site to port took three and a half weeks. The ship made it about halfway back to port in the thick sea-ice, and then was met by the Russian icebreaker Admiral Makarov, that refueled it. I think it took four days to complete the refueling. They then proceeded to the edge of the sea-ice in Barents Sea, but had to wait before venturing out into the open water because a gale was raging and the seas were too high. (I guess icebreakers are not designed for ocean storms.) They had to wait a week for the waves to subside under fifteen feet, but the MOSAiC scientists aboard got to observe how sea-ice fractures under the duress of huge swells. When the gale subsided they rushed across Barents Sea and two days later safely arrived in Tromso. (Likely some of the scientists had further adventures getting back to their home countries through the travel-bans of the Pandemic.)
It will be interesting to see what the Polarstern experiences, heading south.
The storm brought milder air over the arctic sea, including the year’s first patch of above-freezing air north of the Laptev Sea.
The sea-ice “extent graph” shows the typical decline for this time of recent years:
Interestingly, the “volume” graph hasn’t fallen much, suggesting much of the sea-ice lost on the “extent” graph is baby-ice at the periphery, without much bulk to it.