Saturday, August 11, 2012

Storm exacerbates Arctic predicament

Image created by Sam Carana from sea ice maps generated by Polar View at the University of Bremen 
"What a difference a day makes", Sam Carana said when posting above image well before the Arctic was even bearing the full brunt of the storm. The NASA image below was captured on August 6, 2012, and shows that the center of the storm at that date was located in the middle of the Arctic Ocean.

Image by By NASA Goddard Photo and Video
John Nissen, Chair of the Arctic Methane Emergency Group (AMEG), comments:

"The storm is huge, and breaking up and destroying the sea ice that has become thin, as we feared would happen as the thickness has been declining steadily from year to year. Thus, as the end game for the ice, we are seeing more positive feedback and no sign of any negative feedback to rescue the situation.

There are at least three positive feedbacks working together to reinforce one another - and now a fourth on salinity:
  1. The albedo flip effect as sea ice is replaced by open water absorbing more sunlight, warming and melting more sea ice.
  2. As the sea ice gets very thin, it is liable to break up easily and get blown into open water where it will melt more easily.
  3. The open warmer water is allowing increased strength of storms, which break up the ice to make for more open water.
  4. The storms are churning up the sea to a depth of 500 metres, producing salinity at the surface that will mean slower ice formation in winter and more open water next year.
These feedbacks are dangerous for methane. AMEG has been warning that, as the sea ice retreats, storms will warm the sea bed, leading to further release of methane. In ESAS, we only need mixing to a depth of 50 metres - so a storm capable of mixing to 500 metres will really stir things up.

These feedbacks are also dangerous for food security, already damaged through climate extremes induced by Arctic warming, hence our piece in the Huffington Post.

The only way to head off catastrophe is to cool the Arctic, which must involve geoengineering as quickly as possible. We must try to remain positive and determined about this, despite the gloomy news."

Above image shows a retreat in sea ice area to 3.15521 million km2 on the 221st day of 2012, down from 3.91533 million km2 on the 212th day of 2012, from The Cryosphere Today.

The image below, from Polar View at the University of Bremen, shows sea ice concentration at August 10, 2012, with huge chunks of ice visibly detached from the main ice.

(Click here for full-size image)