James Morison of the University of Washington has been studying Arctic sea ice for decades and runs an annual expedition to the North Pole to drop instruments through the ice into the ocean below. Here he lays out one scenario for the forces driving recent dramatic changes in summer sea ice on the Arctic Ocean.
Read more from Morison on Arctic change here: http://j.mp/dotmorison
And more on sea ice in a warming climate here: http://j.mp/DotArcIce
Here's the Web home for the North Pole Environmental Observatory: http://psc.apl.washington.edu/northpole/