SEARCH 2013 Sea Ice Outlook: June report

There it is, the first Sea Ice Outlook of this year. The SIO is organized by the interagency "system-scale, cross-disciplinary, long-term arctic research program" SEARCH (Study of Environmental Arctic Change), and is a compilation of projections for the September 2013 Arctic sea ice extent, based on NSIDC monthly extent values. These projections are submitted by professionals as well as amateurs (public outlooks).

Here's the summary for the June report:

With 23 pan-arctic Outlook contributions, an increase over the last two years (thank you!), the June Sea Ice Outlook projects a September 2013 arctic sea extent (defined as the monthly average for September) median value of 4.1 million square kilometers, with quartiles of 3.8 and 4.4 million square kilometers (Figure 1).

The consensus is for an increasing downward trend of September sea ice extent. We interpret the split of 2013 Outlooks above and below the 4.1 median to different interpretations of the guiding physics: those who considered that observed sea ice extent in 2012 being well below the 4.1 level indicates a shift in arctic conditions, especially with regard to reduced sea ice thickness and increased sea ice mobility; and those with estimates above 4.1 who support a return to the longer-term downward trend line (1979-2007). It is always important to note for context that all estimates are well below the 1979–2007 September mean of 6.7 million square kilometers.

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

All in all a rather conservative outlook, but not as conservative as last year. Of course, the slow start to the melting season doesn't really inspire confidence for a more aggressive contribution.

These are the September minimums for the last 7 years (in millions km2, found here):

• 2005: 5.57
• 2006: 5.92
• 2007: 4.30
• 2008: 4.73
• 2009: 5.39
• 2010: 4.93
• 2011: 4.63
• 2012: 3.61

If you want to compare this outlook with those of previous years, there's an archive on the SEARCH home page (in the left hand bar).

Larry Hamilton has just posted his second Crowd-Source Prediction of Mean September Sea Ice, this post that is just a quick look at the first SEARCH SIO report. Larry writes:

The next SIO deadline is early July. You are all invited to submit, as comments to this post, your best guess for the mean September extent of Arctic sea ice (NSIDC). Your numerical prediction should be in the first line of the comment, followed by at least a sentence or two explaining the basis for your prediction — whether pure intuition, elaborate calculations, whatever you’ve got. Predictions are not bound by whatever you did or did not guess last month. As before, general discussion is welcome too.

So be sure toclick on Larry's post right now, read his in-depth analysis of the first SEARCH SIO, and share your prediction with everyone.

Comments

[Jai Mitchell]

I think that we won't really have a good idea what the storm has done to the poles until the next PIOMAS update comes out. If Piomas remains fairly steady in July then we will exceed the 2012 levels, possibly by a very large margin.

However, I think that we have experienced significant fram transport already, that the quality of the ice has degraded significantly and the only reason that we have such a large sea ice area now is because low quality/broken/slushy ice has been spread out by the storm.

In that event then we will see mid CAB ice loss and an effective doubling of pack ice edge surface for increased exposure to the air and water melt.

So I said 2.8 but that comes with a +/- of 1.6/1.0

[anthropocene]

http://psc.apl.washington.edu/northpole/NPEO2013/WEBCAM1/ARCHIVE/npeo_cam1_20130614202216.jpg

Is that open water on the right side? Looks like we have a beach-side view now. This says something about the state at the pole. Sun is out as well...

[Account Deleted]

2.0 M km2. To melt something, grind it and then heat it, rather than heat it and then grind it. The second worked for last year, why should the first not work for this. And please, North Pole out of the ice, big news and big concern.

[Mignonette]

I have the impression that the discussions on the Forum are more balanced than the ones we are seeing in the crowd-source prediction thread.

There is a tendency for posting very low estimates, far below the levels of 2007 (4.30) and 2011 (4.63) even when area and volume are currently lagging behind 2011.

It seems to me that there is a big focus on the positive feedbacks (like spreading and lack of MYI) while the negative feedbacks are mainly ignored.

[Kevin O'Neill]

The statistical approach has been the best predictor of September SIE. So, if one simply followed the 'best' approach one would predict something lower than 2012. Any prediction larger than 2012 is ignoring the 'best' predictor available.

Obviously just because the overall trend is downward doesn't mean any individual year cannot increase. But predicting that increase (or a decrease larger than trend) gets into more gut feeling, WAGs, or a framework that includes whatever insights we *believe* we know.

Personally, I basically disregard anything that happened before 2006. To include trends and data before then seems like comparing apples and oranges. I also put more stock in volume trends than SIE or SIA trends. Ice is not 2-dimensional and we can be quickly led astray by forgetting that. But we don't have quick access to daily volume numbers the way we do SIE and SIA.

It's easy to question yourself. A few days or a week of numbers that don't go the way you expected can undermine your confidence in your understanding. It is well to remember that at this time of year the arctic can turn on a dime. Area and extent measures are prone to large errors - especially in the last 10 days of June and the first 10 days of July.

Take a deep breath and try not to get too excited until mid-July; then look at the SIE and SIA numbers and see where they sit. Only then will an extra-ordinary 'cold' summer become apparent. The big melt-out years -- 2007, 2010, 2011 & 2012 -- all crossed the CT SIA 6 Mkm^2 mark on day 191 +/- 1 day. But even these 4 years show a final difference in CT SIA of almost 1 Mkm^2. They really don't begin to seriously diverge until *after* day 211 (August 1st).

And since we're really in a new arctic, there's not even any guarantee that these relatively new patterns will hold true.

Personally, I think predictions below 2 Mkm^2 are *probably* unrealistic; just as I think predictions above 5 Mkm^2 are *probably* unrealistic. But I'm not willing to bet much money either way. I don't see any point in criticizing anyone else's prediction because to do so implies that I *know* what is going to happen. I don't. Of course I believe I'm right and anyone that disagrees with me must be an idiot - but don't we all :)

[Susan Anderson]

ot alert (but not wholly so):

I am startled to see that central Alaska is currently 91 degrees fahrenheit (a mite under 33 C)

http://vortex.plymouth.edu/natemps.gif

[Neven]

Wow, that's just as warm as it was in Austria today. Luckily, we only have that two weeks at most per year.

[Tor Bejnar]

Gosh, we in North Florida only have about two weeks per year of 91F maximums. But we also get a couple weeks at 92, a couple at 95 and maybe a week at 100+ (13 weeks worth of 90+ is average, per the statisticians.)
:)

[jdallen_wa]

@Tor - problem is transitions that quickly to that heat at those latitudes can be lethal to wildlife. Consider that polar bears have a challenge when it gets much above 5C. Heat isn't where they are typically, but is a tangible threat.

Other species could be hammered as well. It's all about context.

For example, consider what would happen where you are if temps spent a full week with highs hitting 50C? That's about what we're talking about.

[Kevin O'Neill]

I don't think the University of Tokyo has a SEARCH entry, but they've released a 2013 prediction. They're expecting a 5% decrease from 2012.

[Kevin O'Neill]

I should have searched a little longer before posting the above - the link is just a brief blurb. The full report can be found here.

2013 Summer Arctic Sea Ice Forecast

[Ned Ward]

Kevin O'Neill writes: The statistical approach has been the best predictor of September SIE. So, if one simply followed the 'best' approach one would predict something lower than 2012. Any prediction larger than 2012 is ignoring the 'best' predictor available.

I'm not following you. Why does a "statistical approach" have to predict a lower value than 2012?

If you just fit a linear trend to the last decade's September averages, you'd predict that Sept 2013 would average 3.91, well above the 2012 value. There are of course many other choices one could make for a "statistical approach", but lots of them -- including the ones that seem most logical to me -- don't predict a 2013 average that's lower than 2012.

If you look at the full record since 1979, almost half the years show an increase over the previous year. Four of the past ten years did. There's no reason to assume that 2013 must be lower than 2012.

[Kevin O'Neill]

Ned, a simple linear trend has not been the best predictor. I believe the Gompertz curve is still the best predictor.

Mind you - I'm *not* saying this is the correct approach. But it has been the best predictor so far.

[Ned Ward]

But, Kevin, according to this a Gompertz curve also predicts that 2013 would be above 2012's mean (see Figure 2). In fact, over the short time span I referred to (the past decade) there's not much difference at all between a Gompertz fit and a simple linear fit.

Again, I see no reason to assume that 2013 will be lower than 2012. The most straightforward statistical methods would predict a bit of a rebound after 2012's abnormally low sea ice extent, and the past month's data from JAXA certainly doesn't contradict that idea.

[fryingpan136]

@ Kevin, Fascinating prediction. Their approach and conclusions seem quite reasonable. They have taken into account the motion and thickness of the ice. I would like to see their model also make use of long term weather predictions, say a 90 day forecast, if any exist, for the arctic. I notice the model is the work of graduate engineering students.

[Kevin O'Neill]

Ned - I stand corrected - then any estimate other than 3.8 Mkm^2 would be ignoring the best predictor.

My point remains that criticizing others for their predictions amounts to little more than arrogance. It implies that one *knows* what the final result is going to be. None of us *know* what the September SIE mean will be.

[Ned Ward]

Eh. I don't see anything wrong with commenting on other people's predictions, both in terms of the reasoning used and how closely the results match our own expectations.

True, we don't *know* what the result will be.

But I can certainly generate examples of "better" and "worse" predictions. For example:

(A) "I heard on WUWT that the ice has recovered, so I'm predicting it'll be back to its 1980 level" (i.e., 7.9).

(B) "I compared the PIOMAS volume for this past month in each year (from 2003-2012) to that year's ultimate September NSDIC extent. Based on the most recent volume estimate, I'm predicting this September's extent will be 4.3"

(C) "Based on the alien transmissions I'm receiving through the fillings in my teeth, I predict this September's extent will be 4.3"

I can't speak for anyone else, but I have no problem saying that IMHO (B) is a better prediction than (A). I also have no problem saying that (B) is a better prediction than (C) even though they give the same result.

[David Vun Kannon]

http://nsidc.org/monthlyhighlights/2013/04/glimpses-of-sea-ice-past/

A report on the recovery of data from the Nimbus 1 satellite that flew Aug-Sep, 1964! It caught the Artic minimum/Antarctic maximum (6.9/19.7 for those not clicking the link) by happenstance.

The story shows how important it is to preserve data for future generations of scientific research. It also makes it especially poignant that these NSIDC archives might close for lack of funding!