By Liat Clark, Wired UK

The Arctic ice cap is on course for a record-breaking melt session following a summer of unstable conditions, says the National Snow and Ice Data Center.

[partner id="wireduk"]"The numbers are coming in and we are looking at them with a sense of amazement," the center's director Mark Serrez said. "If the melt were to just suddenly stop today, we would be at the third lowest [ice level] in the satellite record. We've still got another two weeks of melt to go, so I think we're very likely to set a new record."

The center, based at the University of Colorado, has been comparing the data against 2007 sea ice levels, when the Arctic cap shrank to a record low of 4.25 million square kilometres. That rapid decrease was expected and explainable because of enduring patterns of high pressure over the central Arctic Ocean combined with low pressure over the northern Eurasian coast. Throughout 2012, however, conditions have not been consistent – from the end of June the rate of loss was recorded as being 100,000 square kilometers per day, but this figure dramatically doubled for several days in August when a cyclone brought warm winds to the region, with the expanse of open water in the Atlantic continually contributing to the loss. Over the course of just a few days, 200,000 square kilometers of ice disappeared in the East Siberian Sea alone.

Both below and above average temperatures have also been recorded, with areas of Greenland, northern Canada and Alaska seeing temperatures above the water's surface remain between one and three degrees Celsius (higher than average temperatures recorded from as far back as 1981) and parts of eastern Siberia and its sea reaching lower than average temperatures.

On August 13 the remaining surface area was estimated to be 5.09 million square kilometers – that's 2.69 million square kilometers below the 1979 to 2000 average for the same date.

Rather than blaming one-off dramatic atmospheric conditions, such as the summer cyclone, Serrez says if the levels reach an all-time low global warming is to blame.

"The ice now is so thin in the spring, just because of the general pattern of warming, that large parts of the pack ice just can't survive the summer melt season anymore," he said.

While predictions of a total melt during the summer months and its potentially devastating effects on the planet has many worried (Serreze says the rapid melting may have contributed to severe storms in the US in recent years), commercial enterprises are busily jumping at the opportunity to open shop in the Northern Passage. China sent its first vessel along the Arctic route in August, trimming its usual route length by 40 percent, while Germany and Russia are already established players.

Source: Wired.co.uk

Image: NASA Goddard Photo and Video/Flickr