30 March 2011
Maximum Ice Extent Ties Record Low
Every winter, the Arctic ocean freezes and you can literally walk from Canada across the Pole to Russia (except in a few areas that rarely freeze). The stunning loss in Arctic ocean sea ice continues, and while the summer melt gets most of the attention, this winter the amount of Arctic ice was tied for the lowest on record. Here are the official numbers from the National Snow and Ice Data Center:
“On March 7, 2011, Arctic sea ice likely reached its maximum extent for the year, at 14.64 million square kilometers (5.65 million square miles). The maximum extent was 1.2 million square kilometers (463,000 square miles) below the 1979 to 2000 average of 15.86 million square kilometers (6.12 million square miles), and equal (within 0.1%) to 2006 for the lowest maximum extent in the satellite record.”
My good friend Joe Witte at NASA sent me a link to this video showing the freeze up from September 2010 to the beginning of the melt in March:
Why The Arctic Is Warming So Fast
For those who might not know, what’s happening in the Arctic is positive feedback. It’s actually called the ice-albedo feedback and was predicted by climate researchers over 30 years ago. The albedo of an object is how much it reflects the light shined on it and ice has an albedo of around .5 or higher.
As the Arctic ocean air and waters warm, there is less ice. Dark ocean water now covers areas that were bright white, and this dark water absorbs most of the sun’s energy, instead of reflecting it. This of course causes more increase in temperature, resulting in less ice, and increasing the temperature even more. (A very detailed look at this effect is here.)
Even in the 1970′s, many scientists who looked closely at the situation were expecting climate change to first become apparent in the Arctic and that temperatures there would warm much more than in the tropics. So, has it happened? Look at the temperature anomalies for 2010 from the NCDC:
Yes, but that’s just one year you say! Look below:
Now, this comes out just days after a Montana representative introduced a bill that declares climate change a hoax. Fortunately, the U.S. Navy is a bit smarter than a scientifically illiterate representative in Montana, who made his state the laughing stock of the nation. This is the first I’ve ever heard of a lawmaker attempting to repeal the laws of physics.
Good luck with that buddy!