This summer, the Arctic sea ice retreated to 1.70 million square miles (4.41 million square kilometers), hitting its annual minimum on Sept 11, according to a joint analysis by the space agency and the National Snow and Ice Data Center (NSICD) in Boulder, Colorado. This year’s minimum is 699,000 square miles (1.81 million square kilometers) lower than the 1981-2010 average.
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Any day now Arctic sea-ice is going to hit its lowest extent for the year, and once again it’s set to be one of the lowest years on record (the four lowest years have all occurred since 2007).
The animation below, released by NASA researchers together with their report, shows the Arctic sea ice dropping from its wintertime maximum, reached earlier this year on February 25 and found to be the lowest on record, to the summertime minimum documented on September 11.
“The marked energetic mixing we are seeing here at the heart of the Arctic ice-melt zone may prove key in understanding a potential new climate feedback”, Alford said.
On a final note, while it’s true that, as NSIDC added, “the nine lowest extents in the satellite era have all occurred in the last nine years”, why is it that satellites are suddenly relevant? “Dwindling sea ice is a stark reminder of the destruction climate change wages on our most vulnerable wildlife and communities”.
Prof Andrew Shepherd, Director of the Centre for Polar Observation and Modelling at the University of Leeds, told the Guardian that it was also important to establish the sea ice thickness, which can not be picked by satellites over the summer months. The lower ice levels in both seasons confirm predictions of scientists who have long argued that declining Arctic ice would constitute solid evidence that the Earth is warming. As a result, heat is being mixed up towards the surface, and the remaining ice, at a remarkable rate.
“There will always be some years when the amount of sea ice is above the downward trend line and some years when it is below the line”.
Minimum Arctic sea ice extent is probably not the only reason 2015 will go down in the record books. There was no giant late-summer storm to break up ice and lead to melt. The ocean could only attack it from the sides.
The Arctic ice melt didn’t accelerate in June as it typically does due to the higher solar energy the region receives. But faster-than-normal melt began in July and continued through August.
Each summer, Meier says warming ocean waters are finding their way into new imperfections in the sea ice, melting the cover from within. A big “hole” appeared in August in the ice pack in the Beaufort and Chukchi seas, north of Alaska, when thinner seasonal ice surrounded by thicker, older ice melted.
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