August ARCUS forecast poll – What will the September NSIDC Arctic minimum extent be?

Once again, I’m going to give WUWT readers an opportunity to make a forecast for submission, based on voting. See the poll at the end. 

I’ll run this poll each month in the week before the deadline, and we’ll see how we do as the minimum approaches. The value used by ARCUS is the NSIDC value as they say here:

The sea ice monthly extent for September 2010 was 4.9 million square kilometers, based on National Snow and Ice Data Center (NSIDC) estimates.

So don’t be using the JAXA graph to forecast minimums, though it it useful for determining short term trends as it is more responsive than the NSDIC graph below, which is averaged.

Here’s the latest JAXA graph:

JAXA AMSR-E Sea Ice Extent -15% or greater – click to enlarge

On May 30th I submitted the results of the first poll to ARCUS to be included in their June Outlook, as shown below:

Figure 1. Distribution of individual Pan-Arctic Outlook values (June Report)

Download High Resolution Version of Figure 1.

WUWT is second highest, at 5.5 million sq km. Notably missing this year is “Wilson”, who in the last two years started out with impossibly low values such as 1 million sq km. I’ll repeat the poll next week in preparation for the August Outlook. In the meantime, check the WUWT Sea Ice Page for the latest.

and here is the July results, WUWT is still second highest, but down to 5.1:

Credit: Arctic Research Consortium of the U.S. (ARCUS).

Figure 1. Distribution of individual Pan-Arctic Outlook (July Report) values for September 2010 sea ice extent. Credit: Arctic Research Consortium of the U.S. (ARCUS). Click to enlarge.

Download High Resolution Version of Figure 1.

Here’s the poll for the ARCUS August outlook, it will run until July 31st at midnight PST.


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Robert of Ottawa

5.8 Mkm squared


Do I win a grant if I am right?


I’m still going for around the 5.1m mark! (cooling is just around the corner guys!)

I want to predict that WUWT readers will probably adjust their estimate downwards somewhat now that we are getting closer to a result – they give me the impression that they are willing to weigh up the information in a more “realistic” way and not be so much biased by preconceived ideas :-g.


5.2 mil.


I didn’t vote in the previous polls, as I must have missed them as they rolled from a top 5 or so postings. I’ve followed the proceedings though. I think the mean of the WUWT poll has been a bit high, though I doubt it will reach the ’07 minimum. My somewhat self educated WAG is the 4.6 to 4.8 range.

Frederick Michael

I’ll be somewhat relieved if we stay above the 2007 minimum. Way too much ice is going out the Fram Strait this summer, though the Narez Strait may be plugged. Also, the NSIDC density map shows less solid white than I recall from past Julys.


lol At Global Cooling.
It’s about as likely as Jesus return.
I’m going to say 4.4-4.7

CRS, Dr.P.H.

My first prediction was 5.0 MKm2, matching what the Canadian Ice Service predicted. However, watching the recent NSIDC trends, I downgraded that to 4.6-4.8 MKm2.
The Northeast Passage is now essentially open, let’s see when the Northwest Passage opens up. In any event, sea ice age will continue to grow.

I would just like to say that I really like coverage of the ice melt season. So much like a horse race. Is there betting? 🙂

Summoning R Gates…


If all of the Arctic icecap were to melt – that is, all of the 4 – 5 million square kilometers now covered at the minimum point of Sept 15 to 22, what would happen?
Oddly, amid all of the many dozen different college meteorology summaries, class exams, lesson plans and earth science and physics texts I’ve read on-line and on paper, none have ever calculated the actual reason for the recent warming, and none have calculated what would happen if all the ice were gone. Most conventional CAGW paper and lesson plan does discuss the difference in albedo and reflection between ice and water, and a few actually show the calculations. But even those do for a single piece of miraculous square meter of ice: in orbit, directly above the equator on the equinox, during a perfectly “average” day of a perfectly circular earth’s orbit for perfectly flat square meter of perfect substrate at the instant of solar noon. Some continue, like the national ice research center’s website, to wave their hands – so to speak – about albedo feedback and increased melting causing increased heating of the earth. But none have actually shown why a measured 1/4 of one degree warming in the earth’s supposed “average” temperature can actually melt as many tons of ice that they claim.
No calc’s have ever used a real piece of real ocean water (or real Arctic sea ice) with real waves set at the Arctic’s latitude during the entire 24 period of a real day at every relevant part of the year with real values of atmospheric attenuation and real world “rough” ice/air/water albedo and reflectivities and absorption at angles under 15 degrees. So, how can they claim their much-vaunted “positive feedback” for the Arctic sea ice? They have never shown what the feedback is. (Granted, some begin to approach this: I have seen “average” albedo values for ice, pure water, and melted spots. But those albedos are quoted for the equator, when the sun is directly above the surface. For a flat surface -with no waves or wind or ice hummocks and ridges. And even those “average” values for albedo vary all over the map. No reference presents data for the attenuation of sunshine due to clouds for each month of the year in the Arctic. No paper or lesson plan uses actual values for reflection from the ice, the water, or the broken up and irregular pack ice. None list month-to-month values for how much energy is absorbed in the atmosphere before it even reachs the surface to even have a chance of being absorbed by the ice to begin its melting.
If there were a catastrophe could be calculated – and just fear-mongered with exaggerations about future warming and massive feedbacks, you’d think somebody at NSIRD would have published some measured values for the area where the catastrophe were beginning.
Do they somehow claim that increased CO2 levels can heat the Arctic air so high that the sea ice will not re-freeze each November-January-February-March-April when there is no sunshine up for 12 months of the year? Winter average temperature is -25 degrees C. The sea ice will re-freeze each winter. And re-melt each summer.
Further, if conventional CAGW theory holds that Arctic sea ice melting is a definite symptom of CAGW warming, and is at the same time “proof” of that global warming, why have they never calculated how a mere (and measured) 1/4 degree temperature increase in the air melt that many millions of tons of sea ice? (Yes – sea ice is melted from below, from the relatively warmer waters of the Arctic Ocean melting the bottom of the ice faster than the cold air mass above can freeze more. So, why have we never seen calculations of the time of year, average temperature of water, sea ice, and air, and a real value for the heat exchange coefficients?
Worse – the DMI HAS measured the temperatures at 80 north latitude every day since 1958. And Arctic summer temperatures have consistently gone down since that date. Why does Hansen claim his +4 degree rise?

RACookPE1978 says “the DMI HAS measured the temperatures at 80 north latitude every day since 1958. And Arctic summer temperatures have consistently gone down since that date.“.


I’m holding on 5-5.1.
By the way, Anthony, did Dr. Walt Meier get back to you about the orange boundaries for “Arctic sea ice extent”? In a previous post, you wrote:
[Update: Dr. Walt Meier of NSIDC in an email agrees that the orange boundaries are “somewhat arbitrary” and has agreed to explore a “what if” question for me. I hope to have a plot from him using Arctic circle as a boundary in a couple of weeks to see if there is any significant difference – Anthony] My Google-fu seems to be failing me, because I can’t find a follow-up post on that.
REPLY: No he did not. – Anthony

Mac the Knife

I predict the arctic ice mass minimum will be more than enough to make a proper gin and tonic….. but less than the antarctic ice mass (penguin population total mass deducted) +/- 3, naturally!


problems posting on tips & notes, so here goes:
btw nowhere in the 340 pages is “global warming” much less “manmade global warming”, much less CAGW mentioned:
(found on joanne nova)
(340 pages) The Australian Carbon Tax legislation has been released finally: The draft from the Climate Change Department

“Worse – the DMI HAS measured the temperatures at 80 north latitude every day since 1958.”
DMI uses a model to construct the temperatures.


How come people are still betting greater than 6.0 given the current value? That would have to be a massive turnaround with a very poor August followed by a very quick refreeze to give a September figure that high. Stranger things have happened I guess.
The poll seems quite spread out now.

Oh yeah, Brian, have you visited the Iceland Volcano and Earthquake Blog lately and checked out the Katla news? I’m not saying it’s going to, but also not saying that I won’t see Jesus before I die either.

Martin Brumby

Good fun.
But come back when sea ice in February is less than 1.0 Million m2 and I’ll start to wonder if the Thermageddonists are at least a little bit right.

Smokey says:
July 27, 2011 at 7:48 pm
Summoning R Gates…

Oh god please no.
Any break therefrom (the “summoning”) is a welcome respite.
What are you trying to be all of the sudden, Smokey, some sort of medium?
Let him/her rest. No need to excite him/her.
Nothing is said anyways other than 75% AGWist versus 25% Skeptic blah blah blah….and something obligatory about the “AGW Models” and some sort of hand-wringing about sea ice.
No need to summon the spirits. Let him/her save THAT for the ScFi channel.
Smokey steer clear of the drama that is about to ensue…because you mentioned his/her name.
Norfolk, VA, USA


4.6 to 4.7 Million km2….. low.
Just to hedge my prognostication ability, It will more likely be lower than 4.6 to 4.7 Million km2 than higher.


Ed Mertin says:
“….Iceland Volcano and Earthquake Blog lately and checked out the Katla news? I’m not saying it’s going to, but also not saying that I won’t see Jesus before I die either.”
It’s gonna be a toss up. My money is on Hekla. I could be wrong, Katla’s last two events in the list show up as “uncertain” and the new ice craters are tantalizing. Something is up. But Hekla.. well, when it goes it gives very little warning. The last event occurred about 15 to 20 minutes after the associated quakes crossed the threshold of being able to feel them if you were standing on top of them.


5.1 to 5.2 & a rapid freeze thereafter, along the line of 2002.


I suspect the minimum will be very low and the recovery relatively fast. This has been the pattern for a bit. The core ice seems dense and solid, allowing for the same. The Warmists have been hiding or ignoring the thermometer readings for some time. The loss of seasonal ice seems more wind and current driven then atmospheric. Just my thinking.

Alan the Brit

Well, I know nothing! However, I voted fo 5.1-5.2Mkm². Having said that it probably doesn’t really matter what the actual level is at, presuming that it doesn’t exceed 2007. Somebody somewhere will stick a ruler on the trend line & calculate to some umpteenth decimal place that the “rate of melt” was faster than ever recorded before, or some such spurious statistic, just to keep the alarm bells ticking over, or that old chestnutter of “natural forces masking the clear manmade signal”. You see it has to be worse than we thought. Although if these weak & feeble natural forces are so powerful in the first instance one has to ask what is the problem in any case!


RACookPE1978 [July 27, 2011 at 8:06 pm] says:
“If all of the Arctic icecap were to melt – that is, all of the 4 – 5 million square kilometers now covered at the minimum point of Sept 15 to 22, what would happen?”

Nothing at all. Life would continue uninterrupted and unaffected. Business as usual.
Well one thing would happen, there would be a run on Beer, Wine and Prozac, probably diapers too. The bed-wetters would be a mess, first from panic and then later from withdrawal fatigue due to investing so much into so little.
Any AGW cultists care to offer a different scenario?

Kelvin Vaughan

AndyW says:
July 27, 2011 at 10:04 pm
How come people are still betting greater than 6.0 given the current value? That would have to be a massive turnaround with a very poor August followed by a very quick refreeze to give a September figure that high. Stranger things have happened I guess.
The poll seems quite spread out now.
Optimists one end, pessimists the other and the rest in between.

John Marshall

I have reduced my estimate, not least because the observed area is less than my previous estimate. Reality must continue.
There is still time to cross the 2007 line, which it seems to be tryong to do, but there is no worry if it does not only that my latest estimate will be wrong again.
What about ice thickness?

Faleh almutairi

Last day 100000 kilometer disapper on the end of July >>>wow

John Silver

I’ve bet on 5.3 from the start and I’m sticking to it. 5.3 it will be and I will win all the money. Oh, yes!

richard verney

The planet appears to be cooling, and in the short term less ice increases the cooling rate and as we all know, sea temperature is not in itself the only (nor at times the most significant) factor determing the extent of ice/ice loss. The weather patterns are currently such that I recogn that for now we will come close to the 2007 level and I would ‘guestimate’ around 4.7 million sqKm +/- 200,000 sq km.
As a number of people have observed, why the fixation with summer minimums? The waters will refreeze we can be certain of that and I for one would be far more concerned if the ice season was gradually increasing and the trensd was for a significant increase in the summer minimum. I shiver at the thought of seeing such a trend, but do not get hot under the collar at seeing a little less summer artic ice. Its no big deal. .

Nick Shaw

I’m guessin’ 4.5 to 4.6 square klicks but, really, if it’s less, what does it matter?
It’s been less before and we still muddled through.
Personally, I’m looking forward to the first bottles of Yellowknife Caskets wines. It should be a great vintage!

Adriana Ortiz

Seems that Trenberth has turned/is turning
“In light of these several observations, Trenberth concludes that “major challenges remain to improve model simulations of the hydrological cycle.” And until such is accomplished and it is proven that the models can at least correctly simulate something as basic as precipitation, it would seem unwise in the extreme to make major global-economy-impacting political decisions on so flimsy a basis as what today’s climate models are currently predicting, not only with respect to the meteorological phenomena that are discussed by Trenberth, but with respect to the many other extreme weather and climatic events that the world’s climate alarmists use to terrorize the public on a never-ending basis via their over-the-top rhetoric about impending catastrophic consequences if anthropogenic CO2 emissions are not drastically reduced.” from Co2 site


Brian says:
July 27, 2011 at 7:00 pm
lol At Global Cooling.
It’s about as likely as Jesus return.
I’m going to say 4.4-4.7

LOL at global warming.
Its as likely as the global Marxist revolution for which all you AGWers hunger and thirst.
Just because a hazardous and speculative theory about indefinite temperature rise linked to CO2 (in the face of contrary evidence from the palaeo record) is made by the elite and their attendant gullible majority, it doesn’t make it any less stupid and improbable.
I went for 5.2.


steven mosher says:
July 27, 2011 at 9:45 pm
“Worse – the DMI HAS measured the temperatures at 80 north latitude every day since 1958.”
DMI uses a model to construct the temperatures.

Both DMI temperatures and PIOMAS are a mixture of measurements and model calculations.
But I’m guessing – just guessing here – that you like PIOMAS and dont like the DMI temps.

Brian H

There are opposed bumps on the log at each end; 5.4-5.5 vs >4.0<4.5. The former is closer to the true answer, of course, which is 5.2.

Mike M

Perry says: July 27, 2011 at 11:18 pm 5.1 to 5.2 & a rapid freeze thereafter, along the line of 2002.

That’s my estimation as well for the same and other reasons such as that thickness has somehow managed to increase in some areas (10N 180) thus pointing maybe to low ocean temperatures in those regions. May 25 versus July 25 How did thickness increase that much in two months when things are supposed to be melting?


Its a shame there are so few NSIDC historical graph records to compare against. So judging from the 2006 graph I’m going to reduce my minimum estimate from 5.5 to 5.2 as I think that the 2006 drop of just over 1 million sq. kilometers from end of July to September is about what we can expect. To be honest I wouldn’t be surprised if see either a very low minimum or even completely unexpected august increases in ice extent. Its glaringly obvious that we do not yet understand all the variables at play, which makes for interesting science.

richard verney

Adriana Ortiz says: July 28, 2011 at 3:57 am
Is that really an accurate quote from Trenberth? Sounds far too rational. A recognition that the models cannot adequately model a key driver of climate and therefore a cautionary stance should be taken with respect to their ‘predictions’ and economic policy ought not to be based upon model ‘prediction’ how very sensible.
It is not 1st April, is it? .

Dave Springer

My prediction:
Not as ice-free as it was in 1911 when Amundsen made the historic journey through the Northwest Passage.
Wake me up when there’s a commercial shipping lane open.

richard verney

Further to my last post, it appears that Trenberth is merely conceding/recognising that there are problems with the models. It does not appear that he is saying that they should not be relied upon until such time as they can properly model precipitation etc.


I have two methods with my spreadsheet (both combine predictions based off of CT’s area metric and JAXA’s extent metric and then converts that to a monthly NSIDC value). They are 4.495 and 4.675. I’ll average these, so my prediction is 4.585 million km^2. I know they only report to three significant figures…so I’m exactly right whether it’s 4.58 or 4.59 😉 .

Rob Crawford

Wait… I’ve seen a True Believer citing the Arctic ice “melt-off” as “definitive proof” of AGW… now that I see these graphs, I see that four years ago the ice was even “thinner”. So if there’s a trend, it’s swamped by other causes of annual variation, right?
BTW — my prediction is that in 5-10 years, the Arctic sea ice extent will be an “abandoned metric” for the AGW crowd. Like the prediction that the children of Britain will never again see snow, the Arctic will confound their predictions, and they’ll quietly stop citing it as evidence. They will, instead, find something else to wave around as “proof”.


The minimum ice extent will be a record low of all time. This is the beginning of another election year in the USA and the government subsidized scientists will find a way to carve out pot holes and embayments and ignore thin ice to get the number they want.
Did you see in the news the guys that saw the four supposedly drowned polar bears are under investigation and out on administrative leave? Another snow job if you ask me. Cheaters.

t stone

I know that I tend to be optimistic, so I adjusted down a couple of clicks.
Best guess from an interested observer:
4.7 – 4.8


@Dave Springer: Amundsen in 1911?
You mean 1903-until 1906. Why did it take 3 yeas?
It is ironic to read older Blogs with new graphs like this: look for the sentence
“Ice volume has increased by 25% in the last two years, and those looking for a big melt are likely going to be disappointed.” in
and then take a look on the current graph just bleow the quote.
Funny, I think.

Luther Wu


David Schofield

Surely if there is a strong correlation between CO2 and Arctic temperature/ice you can predict the amount of ice next month by the predicted amount of CO2 in the atmosphere [which is easier to predict]. Isn’t that what correlations are?


The trend line for September ice extent 1979-2010 declines by about 81,000 square kilometers per year. If you believe in that downward trend, the best guess for September 2011 would be 5.2 million square kilometers. If you believe in 60-year cycles we’re overdue for some cooling and you should guess above 5.2. If you believe extent will continue its decline and at an accelerating rate, guess below 5.2.