Arctic sea ice at the middle of winter (January-March) is a measure of what’s to come because winter ice is the set-up for early spring, the time when polar bears do most of their feeding on young seals.
[Mid-winter photos of polar bears are hard to come by, partly because the Arctic is still dark for most hours of the day, it’s still bitterly cold, and scientists don’t venture out to do work on polar bears until the end of March at the earliest]
At 12 February this year, the ice was similar in overall extent to 2013 but higher than 2006.
Most polar bears that spend the spring feeding in the peripheral seas of the Arctic Basin (such as the Beaufort, Chukchi, Kara, and Barents Seas) remain on the persistent pack ice of the central Arctic during the summer and this August, that refugium is still larger than Greenland. Most of these bears do not use this July-September Arctic Basin ice as a hunting platform unless they are very lucky: the few seals available are hard to catch. For the most part, polar bears fast or eat very little during the summer whether they are on land or on ice (see references in this post).
Since early June, sea ice experts have been wringing their hands over the melting of Arctic sea ice and offering breathless speculation that this year’s September minimum could be – gasp! – as low as or less than 2012 or even less. But now, as the graph of ice cover at 28 August shows below, that outcome is looking not just unlikely but virtually impossible (the blue line is 2019 extent, red dashed line is 2012, and the brown line is 2016):
As expected, the failure of the ice to remain on track to set a new record September low due to global warming is shrugged off with a reminder that summer ice extent “is sensitive to changes in daily weather conditions.”
Polar bear habitat update for the first week of August 2019 shows there is still more sea ice than average in Hudson Bay, the southern-most area of continuous habitation for this species. That certainly wasn’t part of the predictions of doom, especially since freeze-up in that region for the last two years has also been earlier-than-average which means a shorter ice-free season than we’ve seen for decades.
Despite ice coverage for the Arctic ice as a whole being marginally lower than it has been since 1979 for this time of year, sea ice for the first week of August was also above average around Svalbard in the Barents Sea and higher than the last few years in the Central Arctic, which is a critical summer refugium for polar bears that live in the peripheral seas of the Arctic Ocean, including the Chukchi (see photo below, taken in early August 2018).
Posted in Polar bear attacks, Sea ice habitat
Tagged Central Arctic, Churchill, facts, Hudson Bay, polar bear, prediction, problem bear, range, sea ice, southern, Svalbard, tagged bears
In late June, one of the most powerful icebreakers in the world encountered such extraordinarily thick ice on-route to the North Pole (with a polar bear specialist and deep-pocketed, Attenborough-class tourists onboard) that it took a day and a half longer than expected to get there. A few weeks later, in mid-July, a Norwegian icebreaker also bound for the North Pole (with scientific researchers on board) was forced to turn back north of Svalbard when it unexpectedly encountered impenetrable pack ice.
A polar bear on hummocked sea ice in Franz Josef Land. Photo by Michael Hambrey, date not specified but estimated based on tour dates to be 22 or 23 June 2019.
Apparently, the ice charts the Norwegian captain consulted showed ‘first year ice‘ – ice that formed the previous fall, defined as less than 2 m thick (6.6 ft) – which is often much broken up by early summer. However, what he and his Russian colleague came up against was consolidated first year pack ice up to 3 m thick (about 10 ft). Such thick first year ice was not just unexpected but by definition, should have been impossible.
Ice charts for the last few years that estimate actual ice thickness (rather than age) show ice >2 m thick east and/or just north of Svalbard and around the North Poie is not unusual at this time of year. This suggests that the propensity of navigational charts to use ice ‘age’ (e.g. first year vs. multi-year) to describe ice conditions could explain the Norwegian captain getting caught off-guard by exceptionally thick first year ice. It also provides an explanation for why the polar bear specialist onboard the Russian icebreaker later failed to explain that first year ice of such shocking thickness was truly extraordinary, not just a bit thicker than usual.
Posted in Advocacy, Sea ice habitat
Tagged Barents Sea, extent, first year ice, Franz Josef Land, ice age, icebreaker, North Pole, polar bear, sea ice, Svalbard, thick ice, thin ice
Results from spring Norwegian fieldwork in the Svalbard region of the Barents Sea are in and they show that despite having to deal with the most extreme loss of summer sea ice in the Arctic, polar bears in this region continue to thrive.
Svalbard polar bear territory (managed by Norway) includes sea ice to the Russian boarder to the east as well as the area around the Svalbard archipelago: the map below is from Aars et al. 2017.
Observations were collected around Svalbard by a team lead by Jon Aars and Magnus Andersen of the Norwegian Polar Institute between March and May this year, and posted online 4 June 2019. Kudos to them for making their on-going observations and analysis available, in a timely manner for all to see.
Note that Svalbard is the western half of the ‘Barents Sea’ polar bear subpopulation: in recent years, most of the region’s polar bears have been living around Franz Josef Land in the eastern (Russian) sector where Norwegian researchers are not permitted to work.
Posted in Conservation Status, Population, Sea ice habitat
Tagged Barents Sea, condition, data, litter size, males, Norway, number of cubs, observations, polar bear, sea ice, Svalbard
Abundant ice in Svalbard, East Greenland and the Labrador Sea is excellent news for the spring feeding season ahead because this is when bears truly need the presence of ice for hunting and mating. As far as I can tell, sea ice has not reached Bear Island, Norway at this time of year since 2010 but this year ice moved down to the island on 3 March and has been there ever since. This may mean we’ll be getting reports of polar bear sightings from the meteorological station there, so stay tuned.
Sea ice extent as of 11 March 2019, from NSIDC Masie:
Much of the ice that was blown out of the Bering Sea early in the month has returned and ice in the Gulf of St. Lawrence on the East Coast of Canada is the highest its been in years, threatening to impede ferry traffic between Nova Scotia and Newfoundland, as it did in 2015 and again in 2017. The fishing season off Newfoundland might also be delayed by the heavy ice, as it was in 2017.
Posted in Polar bear attacks, Sea ice habitat
Tagged Barents Sea, Bear Island, Bering Sea, facts, Gulf of St. Lawrence, heavy ice, Labrador, Newfoundland, polar bear, science, sea ice, Svalbard