Arctic Sea Ice Continues its Downward Spiral

At 4.6 million square kilometers, this year’s sea ice minimum is the sixth lowest on record.

Arctic sea-ice cover following this summer’s melt was the sixth lowest on record, the US National Snow and Ice Data Center in Boulder, Colorado, announced on 27 September.

Sea-ice extent bottomed out for the season at 4.59 million square kilometers, tying levels seen in 2008 and 2010. The sea ice reached its last minimum this year on 23 September, one of the latest dates observed.

Calculations from 2017 show that Arctic sea-ice coverage in September has declined by 13.2% per decade.

Since satellite records began, the 12 lowest levels have all happened in the past 12 years. The record low came in 2012 with 3.39 million square kilometers.

The loss of sea ice coverage will likely lead to a positive feedback cycle accelerating the rate of sea-ice reduction as sea-ice reflexivity of the sun’s energy decreases and the ocean’s absorption of the sun’s energy increases.


Photo: “In pack ice, Ross Sea” by Polar Cruises is licensed under CC BY 2.0