Despite pronouncements from one polar bear specialist that “ice in Hudson Bay is in rapid retreat” a look back in time shows that there is more thick first year ice over the Bay this year for the week of the summer solstice than there was in 2004 – and much less open water than 1998.
Below, 2018, June 18 (the week of the summer solstice):
Compare the above to the same week coverage chart for 2004, below:
Ice coverage for some other recent years are shown below compared to 1998, the year the ice breakup pattern on Hudson Bay changed. Speed and melt sequences vary according to the amount of thick first year ice present, discussed previously here.
PS. If you’re wearing white today, flaunt it! Tell your friends and colleagues that you’re celebrating the success of polar bears despite such low summer sea ice since 2007 that 2/3 of them were predicted to disappear.
Posted in Sea ice habitat
Tagged breakup, decline, freeze-up, Hudson Bay, melt, observations, polar bear, retreat, sea ice, solstice, thick first year ice
Wednesday 21 June is the longest day of the year: wear something white tomorrow to acknowledge and celebrate the success of polar bears despite such low summer sea ice since 2007 that 2/3 of them were predicted to disappear.
White tie, white shirt, white socks work too. Keep cool and signal to the world that you love outstanding survivors of climate change, fat though they may be.
Read here and here.
Global sea ice extent at 19 June 2018, well past the end of the intensive spring feeding period for polar bears:
Five years worth of sea ice maps for the same date is hard to come by in this country, since the Canadian Ice Service does not archive their daily sea ice maps. However, due to some forethought, I have at hand ice maps going back to 2012 for the longest day of the year for Canada and archives for other regions provide similar perspective at the solstice.
Few photos of polar bears in June likely exist – too early for most bears to come ashore and the ice too unstable for humans to be offshore [photo above is dated March].
Compare the five maps for Canada and eastern Alaska below. Notice the differences for Hudson Bay: it may seem ironic, but 2012 (which had the lowest September minimum since 1979 due to an August storm) had the most typical Hudson Bay breakup/melt pattern compared to previous years. [Keep in mind this recent post about how much ice can remain even when almost none is visible on the ice maps]
In many regions, polar bear hunting efforts are seldom successful after early June because young-of-the-year seal pups have taken to the water to feed, which means the only prey still on the ice are predator-savvy adults and subadults that have an easy time escaping in the rapidly breaking up ice fields. Bears that come ashore in June likely are not missing much – a little less ice than usual at this time of year is not going to make much difference.
Overall, despite doom and gloom predictions we heard in March 2016 (“wintertime extent hits another record low”), sea ice extent (courtesy NSIDC) at 20 June 2016 was the same at this date as it was in 2010 and 2012 at this time of year – which essentially marks the end of the primary feeding period for polar bears (except for those that live in the Canadian Arctic Archipelago, where seals give birth a bit later in the spring).
And did polar bears die in droves due to conditions in 2010 or 2012, in any subpopulation around the Arctic affected by low sea ice levels? No, they did not. In fact, the subpopulation that had the most recent survey done (Svalbard portion of the Barents Sea – 2015) was not only found to be thriving but numbers had increased markedly (42%) over 2004 levels. Now that’s resilience!
Posted in Life History, Sea ice habitat
Tagged Barents Sea, breakup, Canada, facts, Hudson Bay, polar bear, record low, resilience, sea ice, seals, solstice, Svalbard