2011-05-20 17:13:19Remarkable graph of arctic sea ice volume
perseus

owlsmoor@googlemail...
188.220.205.42

Arctic sea ice volume: The death spiral continues
One-year-old ice in Beaufort Sea now a foot thinner than in 2009
May 19, 2011


In November, Rear Admiral David Titley, the Oceanographer of the Navy, testified that “the volume of ice as of last September has never been lower…in the last several thousand years.” Titley, who is also the Director of Navy’s Task Force Climate Change, said he has told the Chief of Naval Operations that “we expect to see four weeks of basically ice free conditions in the mid to late 2030s.”

Wieslaw Maslowski of the Naval Postgraduate School has “projected a (virtually) ice-free fall by 2016 (+/- 3 yrs).” Contrary to some reporting, that projection has been unchanged for years, though Maslowski is in the process of creating a more sophisticated model that he expects “will improve prediction of sea ice melt,” as he explained to me recently.

Until then, we have some new observational data of Canadian sea ice thickness and this remarkable figure of sea ice volume since 1979 from Neven’s Arctic Sea Ice Blog, based on data from the University of Washington’s Polar Science Center ........




http://climateprogress.org/2011/05/19/arctic-sea-ice-volume-death-spiral/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+climateprogress%2FlCrX+%28Climate+Progress%29&utm_content=Google+Reader

2011-05-20 17:44:36
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.12.82

Might be worth a couple of posts prior to the summer melt season. It could be a biggie, if weather conditions are conducive. 

2011-05-20 20:48:19
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Logicman talks about it in his May update:

http://www.science20.com/chatter_box/arctic_ice_may_2011_update_1-79030

 

Perhaps he could do a crosspost here?

2011-05-21 01:20:36
Rob Honeycutt

robhon@mac...
98.207.62.223

I just sent Neven an email suggesting it would be even more compelling if that chart were animated!  There are some 364 data points.  Give each about 1/3 second and you'd have an amazing 2 minute movie showing the Arctic thawing before your very eyes.

2011-05-21 02:58:07Be sure to read Artful Dodger's comment at the bottom of Logicman's post
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

 

"a new stable regime - one with ice-free summers."

Patrick, much as we might gasp at the implications, a seasonally sea-ice free Arctic Ocean is NOT a stable climate regime. Numerical Modeling and Paleoclimate Studies indicate that there are two stable regimes for the Arctic Ocean in a warming Climate: perpetually ice-covered, and perpetually ice-free.

These modelling result were published by Eisenman and Wettlaufer (2008) "Nonlinear threshold behavior during the loss of Arctic sea ice". The paper (and it's SI Appendix), is freely available from the Journal Proceedings of the National Academy of Sciences.

Figure 3 Bifurcation diagram for the full nonlinear model

The description of "Fig. 3" says in part:
"Under a moderate warming (ΔF0 = 15 Wm−2), modeled sea-ice thickness varies seasonally between 0.9 and 2.2 m. Further warming (ΔF0 = 20 Wm−2) causes the September ice cover to disappear, and the system undergoes a smooth transition to seasonally ice-free conditions. When the model is further warmed (ΔF0 = 23 Wm−2), a saddle-node bifurcation occurs, and the wintertime sea ice cover abruptly disappears in an irreversible process."

Above, "ΔF0 = 15 Wm−2" should be read as "Change in Climate Forcings relative to Time Zero" in Units of Watts per square meter. This means that after the first Sea ice free September, Climate forcings need to increase by only 3 watts per square meter until the Arctic Sea Ice disappears permanently, and irreversibly. Methane Clathrates alone have the potential to increase Climate forcing by 5 W/m^2, in addition to our continued release of C02.

Recent Paleoclimate studies show the Arctic had a perennially sea ice free ocean, an mean annual temperature over 12C, and fossilized Crocodile skeletons found on Baffin Island, the place where many current Commenters speculate will be the last stand for Arctic Sea Ice.

Under our current Climate Policies, it is not a question of if, only of when.

Thank-you for your continued Excellence, Patrick, and enjoy your Summer Adventures of Bike Riding!

2011-05-21 02:59:18
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Good suggestion, Rob!

2011-05-21 21:39:49
perseus

owlsmoor@googlemail...
188.220.205.42

Perhaps an Arctic ice free sea might be the impetuous we need to shock governments into implementing some tough policies which might make a real difference.

2011-05-22 22:29:42
MarkR
Mark Richardson
m.t.richardson2@gmail...
134.225.187.197

If we did tilt to an ice free summer, expect gleeful posts on WUWT and from other deniers about the economic benefits of global warming, thanks to new gas reserves and shorter shipping routes.

2011-05-23 06:17:41
Rob Painting
Rob
paintingskeri@vodafone.co...
118.92.120.245

Yes Mark, and expect much MSM reporting to focus exclusively on the struggle over mining rights etc, and totally neglect to mention global warming.