There's an article about this year's rapid loss of Arctic sea-ice in today's New York Times. Here's the link:
http://www.nytimes.com/2007/08/10/science/earth/10arctic.html As the sea-ice extent declines, it's thickness also decreases. I think it's likely that the thickness will decline so much that there will be the chance of a mechanical failure, even before the extent could actually reaches zero. The result could look much like the breakup of the Larson B ice shelf along the Antarctic Peninsula, which was sudden and spectacular . Last summer, there was the formation of a large polynya which formed just to the north of Alaska. Hers's a discussion of last year's sea- ice cycle: http://nsidc.org/news/press/2006_seaiceminimum/20060816_arcticseaicenews.html That polynya may have been the result of a large tropical cyclone, which moved out of the tropics and then tracked over Alaska and the Arctic. As the sea-ice extent and thickness declines further, one might reasonably expect that other such storms could trigger a shattering of the remaining sea-ice, as the tropical cyclones tend to occur at about the same time as the minimum extent of the Arctic sea- ice. As I understand it, there has never been a period in the history of civilization in which there was no sea-ice over the Arctic. I'll leave it to the experts to tell us just what things will be like once the sea-ice extent has declined to zero, after which there won't be any multi-year ice in the following winter. Given that there is a positive feedback associated with the difference between the albedo of sea-ice and that of open ocean, it's plausible that multi-year sea-ice might not reappear in succeeding years. E. S. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups Global Change ("globalchange") newsgroup. Global Change is a public, moderated venue for discussion of science, technology, economics and policy dimensions of global environmental change. Posts will be admitted to the list if and only if any moderator finds the submission to be constructive and/or interesting, on topic, and not gratuitously rude. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/globalchange -~----------~----~----~----~------~----~------~--~---
