As pointed out by Andrew Kakoona, for Shishmaref, this fall freeze-up was somewhat delayed, not just in the Bering Straits region, but all the way up to Barrow. At Shishmaref during the past 20 years, first ice has appeared on average during the third week of November, based on satellite images, as found by Andy Mahoney and colleagues here at UAF (University of Alaska Fairbanks). A late appearance of first ice would have occurred by the first week of December.
Based on those long-term observations, this year’s delay into the last week of December is unusual. This late freeze-up is part of a very warm year in Alaska, with ocean temperatures much higher than normal and many of the weather stations on land reporting a record warm year for 2016. A climate pattern in the North Pacific, called the Pacific Decadal Oscillation (or PDO) is in part responsible, along with the longer-term warming trend. The big storm that came through the region before New Year’s then added to the lack of ice by blowing out what little ice had formed, throughout the region.
Shishmaref is located in a spot where shore-fast ice stabilizes comparatively late in the year, based on what satellites show for neighboring regions in Kotzebue Sound and elsewhere. Hunters from the area have commented on this in past years. Based on the weather patterns we expect to see it continue for part of the winter, formation of shore-fast ice will likely be further delayed and may not form to the same thickness and stability as in past years. For those interested in a technical paper that has more detail on the normal dates of freeze-up and shore-fast ice formation, here’s the link.
We know from tagged spotted seals that animals typically travel close to the coast during the fall southward migration and tagged animals have all been south of Shishmaref and Bering Strait by late December. As of 3 January 2017, even though most spotted seals have traveled south, a couple of tagged spotted seals remain north of Shishmaref. Updates to tagged animals and archived previous years data can be found here.
No sea ice along the coast of Shishmaref (Photo by Andrew Kakoona)