Wednesday, October 24, 2012

NASA on Earth’s bipolar sea ice behavior

http://wattsupwiththat.com/2012/10/24/nasa-on-earths-bipolar-sea-ice-behavior/

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Opposite Behaviors? Arctic Sea Ice Shrinks, Antarctic Grows
Comparison of (left) Arctic sea ice minimum to (right) Antarctic sea ice maximum for 2012. September 2012 witnessed two opposite records concerning sea ice. Two weeks after the Arctic Ocean’s ice cap experienced an all-time summertime low for the satellite era (left), Antarctic sea ice reached a record winter maximum extent (right). But sea ice in the Arctic has melted at a much faster rate than it has expanded in the Southern Ocean, as can be seen in this image by comparing the 2012 sea ice levels with the yellow outline, which in the Arctic image represents average sea ice minimum extent from 1979 through 2010 and in the Antarctic image shows the median sea ice extent in September from 1979 to 2000. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio and NASA Earth Observatory/ Jesse Allen
The steady and dramatic decline in the sea ice cover of the Arctic Ocean over the last three decades has become a focus of media and public attention. At the opposite end of the Earth, however, something more complex is happening.
A new NASA study shows that from 1978 to 2010 the total extent of sea ice surrounding Antarctica in the Southern Ocean grew by roughly 6,600 square miles every year, an area larger than the state of Connecticut. And previous research by the same authors indicates that this rate of increase has recently accelerated, up from an average rate of almost 4,300 square miles per year from 1978 to 2006...