This year, Arctic sea ice hit a devastating new record low for the summer creating an enormous zone of open water. This vast open area is making sea ice re-freeze more difficult. As a result, rates of re-freeze are lower and slower than in previous years. The effect is that sea ice area anomaly — the gap between the average sea ice for the years 1979-2008 and today’s value is increasing.
Today, that value hit a new record, breaking the old record of 2.65 million square kilometers below average set in 2007 and touching 2.705 million square kilometers below the average range of 1979-2008.
This new record was driven by a slowing down of re-freeze over the past few days, the result of high temperatures and strong storms hampering re-freeze of Arctic seas. Average refreeze rates fell to around 30,000 square kilometers per day over the past few days during a time when a typical re-freeze would indicate 60,000 to 80,000 square kilometers per day or more.
Since the record low anomaly for 2007 is included in the 1979-2008 average, this new record low anomaly is even more substantial than initial estimates would indicate. Thought the gap between today and the average is 2.705 million square kilometers, the gap between today and this date in 1980, for example, is 3.25 million square kilometers. So sea ice area for today is 46% lower than the same day in 1980.
The longer open water remains in the Arctic, the longer that water can contribute to much warmer than normal conditions there. And we can see this now as temperatures over open water areas of the Arctic are between 10 and 18 degrees Celsius above average:
This feedback is an Arctic response to human caused global warming that is currently resulting in more extreme weather within the US and around the world. And, thus far, NOAA’s climate extremes index shows that 2012 is the worst year on record.