Younger Sea Ice Bad for Planet

January 13th, 2008 by Joshua S Hill

New studies will continue to pop up as long as we're alive, I can guarantee you that. There is always something new for us to find, especially on a planet that changes as much as ours does, and already has. So sometimes it's a little hard to give all our attention to every new study that comes our way. It seems as if we need to just take a break every now and then; surely not everything is as important as they say.

Well, I don't think I need to say it, but this latest study is.

A new study from the University of Colorado at Boulder indicates that older ice is giving way to younger ice. And while this may seem a little silly and almost a bit of a given, it is drastically important when it comes to the conditions being suffered by our polar regions.

Consider a baked cake cooked to perfection. A few days after it is cooked it begins to go a little stale, a bit longer if you leave it in the right climate. A week or two later, it's getting staler and harder. Eventually, if you're lazy, you are left with an object most criminals would be fearful of if they ventured too close to your home.

And though that disastrous analogy does nowhere near enough explaining, the same case can be applied to ice. The longer it is formed, the stronger it will get. It builds cohesion, get's thicker, and is harder to melt.
Sadly, the study in question shows that the older ice is giving way to younger ice. And just like your newly baked cake, it is very easy to break it apart while it is new.

Of course these results have vast implications, especially when set up next to the warming waters. "This thinner, younger ice makes the Arctic much more susceptible to rapid melt," said Research Professor James Maslanik of CU-Boulder's Colorado Center for Astrodynamics Research (CCAR). "Our concern is that if the Arctic continues to get kicked hard enough toward one physical state, it becomes increasingly difficult to reestablish the sea ice conditions of 20 or 30 years ago."

The team, led by Maslanik, studied satellite data going back to 1982 and reconstructed Arctic sea-ice conditions over that time. What they found was disturbing; there has been a near total loss of all the oldest, thickest ice, and that 58% of the ice that is left, the perennial ice, is thin ice that is only 2 to 3 years old.

Another study, conducted in September of 07 by CU-Boulder's National Snow and Ice Data Center, showed that last year's average sea ice extent minimum was the lowest on record. This new record shattered the previous record low of September 2005 by a massive 23%, or by about 1 million square miles; that is an area about the size of Alaska and Texas combined.
The team tracked these changes using a method developed around creating signatures of individual ice sections, roughly 15 miles square. Using their thickness, roughness, snow depth and ridge characteristics, they tracked them through the study period as they were maneuvered by the Arctic winds and currents.

"We followed the ice in sequential images and track it back to where it had been previously, which allowed us to infer the relative ages of the ice sections," said CCAR's William Emery.

"These conditions are setting the Arctic up for additional, significant melting because of the positive feedback loop that plays back on itself," said another author, CCAR's Sheldon Drobot.

"Taken together, these changes suggest that the Arctic Ocean is approaching a point where a return to pre-1990s ice conditions becomes increasingly difficult and where large, abrupt changes in summer ice cover as in 2007 may become the norm," the research team wrote in Geophysical Research Letters.

University of Colorado at Boulder - Older Arctic Sea Ice Is Giving Way To Young, Thin Ice, Says CU-Boulder Study

Photo Courtesy of oliptang via Flickr

Posted in Climate Science & Research |