SEARCH 2011 Sea Ice Outlook: August report

SEARCH (Study of Environmental Arctic Change) has released its third Sea Ice Outlook report for August.

Here's their summary:

We received 21 responses for the Pan-Arctic report (Figure 1), with estimates in the range of just below 4.0 million square kilometers to as high as 5.4 million square kilometers for the September arctic mean sea ice extent. As in the July Outlook, the median value was 4.6 million square kilometers with quartile values of 4.3 and 4.6 million square kilometers, a rather narrow range. All contributions are well below the 1979-2007 climatological mean of 6.7 million square kilometers, and also below all values seen prior to 2007. Thus, the low values observed the last four summers are expected to continue again this September. On a regional level, the long-term downward trend is expected to continue in all regions except the Greenland Sea.

And here's the figure showing all the projections (click for a larger version):

So the median is 'stuck' at 4.6 million square km. Jinlun Zhang's projection - based on the PIOMAS sea ice thickness model - has gone up from 4.3 to 4.6 million square km. We see Lucia Liljegren from the Blackboard blog make a contribution, and of course our very own Chris Randles and Larry Hamilton have submitted their projections again. The WUWT poll went from a 5.1 to a 5.0 million square km prediction. NSIDC's Walt Meier's group started with a 4.7 million square km prediction, now 4.5 million square km.

Just for reference, these are the September average extents as calculated by NSIDC for the period 2005-2010 (in million square km):

2005 5.57
2006 5.92
2007 4.30
2008 4.68
2009 5.36
2010 4.90

Comments

[Artful Dodger]

I have posted a comparison between the PIOMAS prediction for SIE and AMSR-E observations from Uni-Bremen on Aug 12, 2011 over on the PIOMAS July page:

http://neven1.typepad.com/blog/2011/08/piomas-july-2011.html?cid=6a0133f03a1e37970b014e8a9d8c75970d#comment-6a0133f03a1e37970b014e8a9d8c75970d

[Ennis George]

"On a regional level, the long-term downward trend is expected to continue in all regions except the Greenland Sea."

Would this not be expected since the major advection route for Arctic Sea ice is through the FRam Strait into the Greenland Sea?

[maltose]

After watching the PIOMAS seasonal outlook animation again, it seems that from mid-August to the end of September, the extent really tanks on the Russian side. A prediction of things to come?

[maltose]

Here is the animation:
http://psc.apl.washington.edu/zhang/IDAO/seasonal_outlook.html

[Seke Rob]

That's a superb animation and with the daily data, albeit totals only, allows for some interesting calculations to ponder on for those that have been very quick to dismiss this project over Cryosat-2 as the new gospel from the first pass.

thanks

[Craig Dillon]

As I understand it, PIOMASS is a model that is used by the Navy to project where their subs can surface in the Arctic without encountering damaging ice. The need to be very cautious about damaging a sub, or the expense of sending it someplace where it cannot surface, leads me to believe that PIOMASS probably overstates its ice projections. Therefore, I do not recognize it as a valid climate model.
Thank you

[Kevin O'Neill]

Craig - I believe you might be confusing PIOMAS with PIPS. PIPS is the US Navy product and PIOMAS is from the Polar Science Center -- a department within the Applied Physics Laboratory at the University of Washington.

[Ennis George]

@Craig Dillon

Craig, how models are used is quite different from what the model actually measures and reports on. For example a model might say that the ice is 1 meter thick +/- 20 cm. The user would the decide to build in a margin of error based on an Expected Value risk assessment. For example a sub costing $5 billion dollars and carrying 100 men might warrant building in a safety margin of 100 cm while an ice breaker costing $5 billion might not need any safety margin.