Arctic ice extent (at 14.1mkm2) on 15 April, was virtually identical to 2014 on that date, and higher than 2006. But the record goes to Davis Strait, which recorded the highest ice extent since 1971 for the week of April 16, while the waters of Eastern Newfoundland to the south (where most harp seals have their pups) had the third highest ice extent since 1969. Lots of fat baby seals are just what polar bears need at this time of year.
Figure 1. From NSIDC, 2015 sea ice extent (dark blue, 14.1mkm2) compared to 2006 and 2014 at April 15 (latest date available). Click to enlarge.
Polar bears gorge on young seals they catch from the sea ice between March and June, so the condition of sea ice in spring is critical. As I suggested earlier this month, the prognosis for polar bear habitat this spring is excellent, despite suggestions otherwise (picked up by Breitbart London here).
So, despite calling an alarming-sounding “record low” maximum extent for late February, followed by a bit of a climb-down, NSIDC ice charts show that spring sea ice is not lower than ever this year.
Figure 2. Davis Strait ice cover from1971 to 2015 for the week of 16 April: 2015 had the highest extent on record for this week, well above the long-term average. Canadian Ice Service graph. Click to enlarge.
Figure 3. Eastern Newfoundland ice cover from1969 to 2015 for the week of 16 April: 2015 had the third highest extent on record for this week, well above the long-term average. This region (see red inset map, upper left) is the largest pupping grounds for harp seals, which has been good news for southern Davis Strait polar bears, one of the most southerly subpopulation segments. Click to enlarge.
Figure 4. Barents Sea ice (Norwegian Ice Service, 16 April 2015) is lower than average in 2015 for this date and lower than the last few years (see “Icechart Archive”). However, there appears to have been enough ice over the last few weeks for females that spent the winter in land-based dens to get their new cubs out onto the ice and begin hunting. Once they are on the ice, they can travel with it as it moves.
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