Arctic sea ice formation off to slow start in 2016
But 2015 saw one of the lowest sea ice maximums on record
The first week of 2016 has seen very slow Arctic sea ice growth, the Colorado-based National Snow and Ice Data Center said in a Jan. 5 update.
That’s not a big surprise, given the warmer temperatures recorded in Arctic regions in recent weeks. And it’s consistent with the positive phase of Arctic wind currents through the month of December, which bring lower-than-normal pressure over polar regions.
Sea ice extent for December averaged 12.3 million square kilometres, the fourth lowest December extent in the satellite record.
The start of the New Year caps 2015, which saw one of the lowest sea ice maximums on record.
An NSIDC review notes 2015’s record-low Arctic sea ice maximum was recorded on Feb. 25, among the lowest noted in the 37-year satellite record.
The NSIDC says this was likely a result of very warm conditions in Russia’s Sea of Okhotsk and the Barents Sea, both registering temperatures four degrees Celsius above average.
The fourth-lowest Arctic minimum took place in September 2015, likely the result of a warm July and increasingly young and thin ice cover, the NSIDC reported.
Across the Arctic, sea ice growth slowed towards the end of 2015, nearly stopping altogether in the first days of the New Year, due to a period of unusual warmth.
And that appears to support a trend seen in recent years, the NSIDC said, where large polynyas appear in the Beaufort and Chukchi seas in late summer.
Another big event in 2015: the Antarctic region’s return to average levels of sea ice extent, after more than two years of record and near-record highs.
From February 2013 through June 2015, Antarctic sea ice was at near-record daily extents, setting winter records in 2012, 2013 and 2014.
But during 2015’s mid-winter period in the southern hemisphere, Antarctic sea ice growth slowed.
Since then, ice extent in the southern hemisphere has been slightly above average, likely due to a strong El Nino effect.