Tuesday, August 14, 2012

Disturbing Arctic Sea Ice News

Before my concentration on Penn. Marcellus news and the summer blogging doldrums, I was frequently posting on climate change and suggesting is it should be a big issue in the election - "It's the climate stupid."  During my slowdown, weather and climate have become big news with the record heat and drought.  Jeff Master's Weather Underground blog has become a drumbeat of a destabilized climate. Here are just a few entries from July:
   Record warmth at the top of the Greenland Ice Sheet
   Historic 2012 U.S. drought continues to expand and intensify
   June 2012: Earth's 4th warmest June; heavy rains in Beijing kill 37
   Greenland experiences melting over 97% of its area in mid-July
   Oil industry-funded "BEST" study finds global warming is real, manmade
   July 2012: hottest month in U.S. history
You get the picture. Now one thing I used to post quite regularly were Arctic sea ice coverage images from the National Snow and Ice Data Center.  We've seen some high amounts of melting this year, but I found the data posted yesterday unsettling. First, look at the trend and see how the rate of melting had recently increased:
Then look at the ice coverage, notice the the big break-up near the Bering Sea along the Siberian coast:

The reason I find this image disturbing is because it reminds me of ice on a frozen puddle just before it completely melts, when it's soft, fragile, thin and full of holes.

The accelerated melting and break-up is due in part to an unusually strong summer storm in the Arctic. In and of itself this is not earth-shattering. Though uncommon, strong summer storms are not unknown, but this one comes as part of a package deal with more heat and moisture in the Arctic and more melting.  Recent data suggests that the sea ice is melting faster than expected, maybe as much as 50% more, and the volume is decreasing as well. The volume is a crucial element here.  The Arctic will continue to freeze over in the winter, but much of that will now melt in the summer. Thus the we will see more and more thin (low-volume) single-year ice instead of thicker multi-year ice. This ice is more susceptible to melting, which leads to more melting in the summer, less high-albedo ice to reflect sunlight, more exposed water to absorb and retain heat, delayed onset of winter freezing and thinner ice. Rinse and repeat.

The rapid decrease in Arctic sea ice is what caused me to change my thinking that climate change was a long-term problem that would incrementally affect us to a short-term unpredictable crisis. A change in the Arctic climate affects storm generation and jet-stream patterns, more convoluted jet stream paths means greater and more unpredictable shifts in weather at lower latitudes and we could see wide swings in winter from intense snow and rain storms to record warmth, maybe in a single season.

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