The official winner of the ice bet is…ta ta ta da… Jared! No arguments about the CT vs JAXA permitted. The rules were JAXA! 🙂
Jared, who avoided the wild exuberance of some bet was within 10,100 km^2 of the correct level, underestimating just a hair. Had a little more ice formed, MartinGAtkins would have won the brownies. Martin over shot by only 26,5000 km^2.
| Jared | 9.15E+06 | -1.01E+04 |
| Accumulating Average | 9.16E+06 | 0.00E+00 |
| MartinGAtkins, | 9.19E+06 | 2.65E+04 |
The average bet was 4.59E+05 km^2 too high. (Two people admitted to misunderstanding and thought they were supposed to bet the winter maximum. ) I was too pessimistic, and underestimated the NH JAXA ice extent by 4.32E+05 km^2, which is an order of magnitude further off than Jared or Martin.
The prize for furthest from correct guess goes to Dan Hughes, who was off by 1.33E+07 km^2. 🙂
How does this NH sea ice extent compare to other years?
Part of the fun of this bet was the limited amount of JAXA data available for past years, which begins in 2002, and which is missing measurements for Nov1-7 in 2003! This year’s Nov 1-7 NH JAXA NH Sea Ice Extent happened to exceed all past Nov 1-7 ice extents in that particular record.
Values for NH Sea Ice Extent for various weeks reported by JAXA are illustrated below:
Out of curiosity, I added the OLS fit to the Nov 1-7 data before and after addition of the 2008 value. The light blue represents the fit to 2002-2007 data for the extent; the dark blue represents the fit including the 2008 data.
I also added a dotted line to show how all previous values compare to the most recent measurement. As you can see, the current value is a maximum, but the rapid ice recovery is not enough to negate the general downturn trend in the JAXA record.
Jared… Now to get your brownies!
Jared, please click the contact me button and send me your address. Or just leave a comment and I’ll reply so you’ll have my real email.
Then assuming you live in the lower 48 of the US, I can bake brownies and get them off to you. (Recall the rules: If you live elsewhere, you are to designate someone else to get your brownies. Speedy postage to outer slobobia is…well… expensive.)
Congratulations to Jared. Enjoy you well-deserved cookies/brownies/whatever!
If I recall, the winning bet was fairly close to both the median and mean of the “ensemble” (sic) of bets. I am confident that IPCC will duely note this triumph for their “means-of-the-models” deterrmination of uncertainty in their next report 🙂
Cassanders
In Cod we trust
Cassanders–
Those who support the “SD” interpretation for comparing means will certainly find that our method is not inconsistent with the data. I think I need to test the SE method and/or adapt some method of Santer.
Hey, glad I checked back in on this, almost forgot about it! 🙂 Looking forward to the brownies, Lucia, thank you!
The chart is interesting in that even without 2007 there’s a growing divergence between the earlier weeks’ averages and the Nov 1-7 time frame. So it would seem as if the ice extent rebound has been growing at an increasing rate.
Congratulations Jared, one more day and those brownies would have been mine. A hand shake to Andyw who came close to snatching second place.
Am I hurt, bitter and vengeful? Yes, yes, all these things, but I can hold my head high knowing my climate model is robust within a 90% degree of certainty. Thank you our kind sponsor Lucia. Squirrels
have been known to bite their own tails off just for a taste of those brownies.
Please as you all make your home, deposit your rubbish into the appropriate recycle bins located at the exits to the arctic circle.
Not necessarily groundbreaking news, but the nansen ROOS ice area for nov 9 is in. By eyeballing, it looks like the Ice Area now is at, or may even have slightly surpassed the 1979-2007 mean, while Ice Extent now is within the men -1SD range.
http://arctic-roos.org/observations/satellite-data/sea-ice/ice-area-and-extent-in-arctic
Cassanders
In Cod we trust
Let’s see if they show…. These should auto-update:
I assume this ice is really thin though… right?
Yes, it will curently be thin, as large areas have grown new ice this fall. But some caveats: I suspect the concept “multi-year ice” is being used for several things. The straightforward “mental picture” would be ice from previous year(s) having survived the melting season. However, I think very thick ice < 1 year can easily be made when wind and wind-driven currents pushes larger ice areas together. In the Nansen vernacular: SKRUIS. (SKRU=Screw or Churn, IS=ICE)
I think plate tectonics could be a useful metaphor.
I do still miss a clarification from the readers if also “SKRUIS” in fact is measured as “multi-year ? (I can easily have missed a response) Does anyone have a reliable definition out there?
BTW, I recently saw anecdotal information from fishermen having had to leave the northernmost areas in October . According to the informant, they haven’t had this onditions for at least a decade.
Cassanders
In Cod we trust
Note the small slope decrease in the area plot very near the end of October and the small increase in slope in very early November, that’s the (smoothed in the NANSEN plot) data we’re now seeing from CT almost a week late.
There’s been some argument about whether areas that were considered open water were actually ice with water on top which wouldn’t take much to refreeze.
BarryW (Comment#6494) November 10th, 2008 at 4:20 pm,
But for that to make a difference, you would have to show that melt pools are more prevalent and cover a larger proportion of ice now than they used to. Otherwise, it may bias the total, but not the trend. I think.
DeWitt Payne (Comment#6496)
I was just some comments I remember from CA, nothing more than that.
I’m still wondering about the rate of extent change that shows up in Lucia’s graph that I mentioned in Comment#6464. What could cause that? Is the ice just been thinning in the winter but covering the same extent, so that the volume of winter ice and summer have been following the same trend which is just not as obvious in the extent?
Congrats, Jared. That slight downturn in the last ten days of October kept my SWAGuesstimate from even coming close. Still. Nice to see the ice doing such a good rebound.
Well done Jared, and thanks to Lucia for adding a bit of fun to the climate debate.