Arctic sea ice nearing annual minimum extent: data centre

Arctic sea ice extent for August was 5.61 million square kilometres. The magenta line shows the 1981 to 2010 median extent for that month. The black cross indicates the geographic North Pole. (IMAGE COURTESY OF THE NSIDC)

A downward trend: this graph from the National Snow and Ice Data Center above shows Arctic sea ice extent as of Aug. 31, along with daily ice extent data for four previous years. 2015 is shown in blue, 2014 in green, 2013 in orange, 2012 in brown, and 2011 in purple. The 1981 to 2010 average is in dark gray. The gray area around the average line shows the range of the data. (IMAGE COURTESY OF THE NSIDC)

If you live near Baffin Bay or Hudson Bay, you might have trouble accepting the forecasts showing that this year’s minimum sea ice extent, which typically occurs in mid to late September, is likely to come in as the third or fourth lowest in the satellite record.

But that’s the latest from the Colorado-based National Snow and Ice Data Center, which issued its latest news last week, based on recent satellite images.

Sea ice extent remains below average in nearly every place around the Arctic except in Baffin Bay and Hudson Bay, where some ice still persists in sheltered coastal areas, the NSIDC said.

And there’s even smooth sailing in the Northwest Passage, if you stick to the southerly route, its images show.

This route passes south of Prince of Wales Island and Victoria Island before entering the Beaufort Sea south of Banks Island.

Overall, August saw “a remarkably steady decline in Arctic sea ice extent” — and at a rate that’s slightly faster than the long-term average, the NSIDC said.

While the rapid pace of daily ice loss seen in late July 2015 slowed somewhat in August, the data centre said the pace of loss increased slightly toward the end of the month so that by Aug. 31, Arctic sea ice extent was only slightly greater than on the same date in 2007 and 2011.

Sea ice loss for August averaged 75,100 square kilometres per day, compared to the long-term 1981 to 2010 average value of 57,300 sq km per day, and a rate of 89,500 sq km per day for 2012, the NSIDC said.

The NSIDC’s forecast places the upcoming daily Arctic sea ice minimum extent between third and fourth lowest since the satellite record started in 1978, with fourth more likely.

All four of the lowest extents have occurred since 2007, the NSIDC said.