The Arctic Ocean’s ice cover has decreased to its lowest ever recorded size, and scientists say the melt season still has a few more weeks left.
The records are based on satellite records dating back to 1979, and scientists use five-day averages when calculating measurements to account for day-to-day anomalies.
The above image shows the extent of Arctic sea ice on August 26, 2012.
The area covered by ice stood at 4,1 million square kilometres on Sunday, which was the average after five consecutive days, according to data compiled by the US National Snow and Ice Data Center (NSIDC) in Boulder, Colorado, the Japanese Aerospace Exploration Agency, and Norwegian, Danish and other government monitoring organisations like the NASA Goddard Space Flight Centre.
The previous lowest recorded level was 4,17 million square kilometres in September 2007.
Walt Meier, a research scientist at the NSIDC, said the ice was shrinking at a record pace this year, and was one of the most visible signs of climate change.
It shrank about 17 per cent in the past 11 days.
According to Meier:
We’ve lost over a million square kilometres in the last few weeks. I would definitely bet we’d go below 4 million square kilometres in the next few days and that’s never been seen before in our satellite records.
If one looks at the average annual minimum area the ice cap covered from 1979 to 2010 – 6,29 million square kilometres – it’s easy to see that something is different.
Arctic temperatures from June through mid-August were two degrees Celsius to three degrees Celsius warmer than in a typical year.
Meier continued:
It used to be that the Arctic ice cover was a huge block of ice — it melted from the edges – but now it’s more like crushed ice. Parts of the Arctic have become like a giant slushy. The ice cover gets more and more vulnerable to these extreme conditions. The Arctic has become like a fighter with a glass jaw.
Sea ice melts every summer and typically starts to freeze again in September, and the NSIDC says that oceans with less ice reflect less sunlight, exacerbating rising temperatures. So once it gets quite bad, it can get worse. And with two weeks of melting still to come, the record may again be beaten this year.
[Source: Bloomberg]
