Posted on June 8, 2021
Winds primarily cause the apparent sea ice ‘breakup’ in late spring through the widening of persistent polynyas and shore leads. This year the development of critical open water areas in Canada (which are important feeding areas for polar bears) is on track with previous years in most areas, although there is a lot of year-to-year variability.
Below are sea ice charts for Canada from 6 June 2021 compared to others back to 2013 at about the same date from the Canadian Ice Service.
See the video below of Sea Ice in the Beaufort Sea, April 25 to May 17, 2021 (from NSIDC, 8 June 2021):
Compare the above to previous years at about the same time.
2014 (17 June is the closest I have in my archive for 2014)