Please tell me if I'm overreacting, but in my last post comparing 2007 and 2010 ice concentration maps Evilreductionist mentioned a huge drop in current Arctic Basin sea ice area over at Cryosphere Today. I looked at this graph a few days ago and nothing much seemed to be happening, but look at this:
It corresponds well with this graph and its extraordinary updates in the past few days:
I think this is exceptional (I have to, I'm an alarmist). Either way, it's on my 'to keep an eye on'-list as of this minute.
Yeah, that's a pretty remarkable jump in the anomaly, all right. Wish I had something to say about that I haven't already said about some of the previous developments of this extraordinary melt season.
(Shakes head.)
Posted by: Kevin McKinney | June 28, 2010 at 05:08
The drop in sea ice area is impressive. More impressive is the date it occurred.
The Arctic Basin began its annual melt about 12 days earlier than 2009.
(look at the far left of the Arctic Basin graph).
Earlier onset of melt allows loss of more ice. Later freeze-up allows less to regrow.
When the length of the melt season passes a tipping point, Arctic Basin ice will be unable to recover and we will soon have a seasonally ice free Arctic (I estimate 2013).
If other feedbacks continue to extent the range of melt/freeze dates, we will have a perennially ice free Arctic Ocean (a recent paper said perhaps only decades from now).
Then, when summer SST's reach 28C, we will see Arctic hurricanes. How's that for alarmist?
Posted by: Artful Dodger | June 29, 2010 at 19:56
(Shakes head--again.)
Posted by: Kevin McKinney | June 29, 2010 at 20:22
Dodger, have you got a reference for that paper? I'd like to look it up...
Posted by: Hottopicnz | June 29, 2010 at 23:11
Hot-NZ, i refer to you to this paper:
"Nonlinear threshold behavior during the loss of Arctic sea ice"
from the Proceedings of the National Academy of Sciences
December 24, 2008
You can read the complete paper online:
http://www.pnas.org/content/106/1/28.full
I also recommend this (PDF available at the bottom of the link above):
"Tipping Elements in Earth Systems Special Feature: The future of ice sheets and sea ice: Between reversible retreat and unstoppable loss"
Posted by: Artful Dodger | June 30, 2010 at 10:04