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What will the NSIDC 2015 Arctic SIE September minimum be?

Between 5.25 and 5.5 million km2
3 (2.8%)
Between 5.0 and 5.25 million km2
7 (6.6%)
Between 4.75 and 5.0 million km2
9 (8.5%)
Between 4.5 and 4.75 million km2
10 (9.4%)
Between 4.25 and 4.5 million km2
11 (10.4%)
Between 4.0 and 4.25 million km2
14 (13.2%)
Between 3.75 and 4.0 million km2
12 (11.3%)
Between 3.5 and 3.75 million km2
12 (11.3%)
Between 3.25 and 3.5 million km2
10 (9.4%)
Between 3.0 and 3.25 million km2
7 (6.6%)
Between 2.75 and 3.0 million km2
4 (3.8%)
Between 2.5 and 2.75 million km2
1 (0.9%)
Between 2.25 and 2.5 million km2
0 (0%)
Between 2.0 and 2.25 million km2
2 (1.9%)
Between 1.75 and 2.0 million km2
0 (0%)
Between 1.5 and 1.75 million km2
0 (0%)
Between 1.25 and 1.5 million km2
1 (0.9%)
Between 1.0 and 1.25 million km2
1 (0.9%)
Between 0.75 and 1.0 million km2
1 (0.9%)
Between 0.5 and 0.75 million km2
0 (0%)
Between 0.25 and 0.5 million km2
0 (0%)
Between 0 and 0.25 million km2
1 (0.9%)

Total Members Voted: 103

Voting closed: June 14, 2015, 04:02:42 PM

Author Topic: NSIDC 2015 Arctic SIE September minimum: June poll  (Read 42098 times)

epiphyte

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #50 on: June 14, 2015, 06:48:39 AM »
Did anyone get 2012 right for the June SIPN? excluding those who always go low?

Why exclude those who always go low? At this time of year when there is no reason not to go low is it such a crime to say so? IMO we are in an era where until the end of June, even mid-July at least, a) anything is possible... and b), the combination of unpredictable circumstances which will lead to a record low grows increasingly more likely every year. So my strategy is to assume the worst. I'm no spring chicken but I think it's very likely that I'll live long enough to be right it the end :)

Juan C. García

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #51 on: June 14, 2015, 07:07:54 AM »
Well, 9 hours to make your vote (or change it if you want to...).
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

cesium62

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #52 on: June 14, 2015, 08:12:51 AM »
Lots of confusing indicators this year with no real explanation of why we are so low. 

A warm eastern Pacific is blowing hot moist air up through the Bering.  And the Mackenzie watershed.

Neven

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #53 on: June 14, 2015, 10:32:41 AM »
I was considering going one bin lower, but given that things are slow in the Arctic right now and there doesn't seem to be happening much wrt melt ponds, I think I'll stick with 4.75 to 5.0 million km2.
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AySz88

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #54 on: June 14, 2015, 10:48:04 AM »
Unfortunately I think there's a bit of a bias being introduced by the largest bin maxing out at 5.5...  A bunch of fairly recent years are right around there, and it looks like the voting is brushing up against that maximum.  Any chance of centering next month's options around 4.5 or 5-ish?  (How many options can a poll have on this forum?)

Neven

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #55 on: June 14, 2015, 11:06:42 AM »
Unfortunately I think there's a bit of a bias being introduced by the largest bin maxing out at 5.5...  A bunch of fairly recent years are right around there, and it looks like the voting is brushing up against that maximum.  Any chance of centering next month's options around 4.5 or 5-ish?  (How many options can a poll have on this forum?)

We've discussed this more or less before (I believe this is the third year of polls on the forum), but I'll add two more bins on next month's poll, even though NSIDC SIE September average hasn't exceeded 5.5 million for almost 10 years now.

BTW, thanks for voting, everyone.
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Lord M Vader

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #56 on: June 14, 2015, 11:20:48 AM »
I changed my vote to 5,0-5,25 as the June stall have emerged..

106 votes Neven, great!!

//LMV

DavidR

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #57 on: June 14, 2015, 03:20:19 PM »
It is worth looking at where the large  falls in 2012 in the weeks leading up to this date came from.

https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-area-regional.png

Although Wipneus's figures are for area, we see 400 K lost in the Bering which has had no ice for the past 4 weeks. Hudson Bay lost  200 K more than this years but was still above the current levels, Chukchi also lost 200 more but was still above current levels. Only the Beaufort which lost  nearly 200K more was significantly below at this stage and that  has only occurred in the past week.  I  doubt that this current 'pause' is much more than a bit of wind spreading out the ice which may in the long run result in greater melting.
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AySz88

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #58 on: June 14, 2015, 03:38:53 PM »
even though NSIDC SIE September average hasn't exceeded 5.5 million for almost 10 years now.

Just to be clearer, the consideration is that the options aren't (literally) balanced around a center (in this case, a "center" might be something like the median from the previous poll, the number from last year/linear trend/running average, or some other "unskilled" starting forecast).  Literature (ex. see #5 here) would suggest that would have some unwanted influence on the results.  Though admittedly, there's hardly a "right" answer and so any choice would nudge things a bit (and yes, oddball guesses low are slightly more justified than oddball guesses high).

I'd also hope people are quantitatively creating a guesstimate and then looking at the options, instead of qualitatively selecting among the options, but you really never know... :p
« Last Edit: June 14, 2015, 03:44:20 PM by AySz88 »

Shared Humanity

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #59 on: June 14, 2015, 04:01:50 PM »
Recognizing today's deadline and having surveyed the recent research and  feeling the pressure to get  this right, I have no choice but to answer in the manner that I  have answered polls from previous seasons and reluctantly admit that......

I have no clue  whatsoever!!!!!

Shared Humanity

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #60 on: June 14, 2015, 04:05:48 PM »
While I visit this site daily and learn a great deal, I feel we would be well served if these polls would provide a decisive choice for the clueless.....something like..


IHNFI!

Richard Rathbone

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #61 on: June 14, 2015, 05:19:31 PM »
Unfortunately I think there's a bit of a bias being introduced by the largest bin maxing out at 5.5...  A bunch of fairly recent years are right around there, and it looks like the voting is brushing up against that maximum.  Any chance of centering next month's options around 4.5 or 5-ish?  (How many options can a poll have on this forum?)

We've discussed this more or less before (I believe this is the third year of polls on the forum), but I'll add two more bins on next month's poll, even though NSIDC SIE September average hasn't exceeded 5.5 million for almost 10 years now.

BTW, thanks for voting, everyone.

Of the last ten years, 2 are off the top of the range and 3, including both the last two years, are in the top bin. If you curtailed it in a similar way at the bottom, the lowest bin available would be about 4.25 rather than 0.

wili

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #62 on: June 14, 2015, 09:16:02 PM »
I think the poll distribution reflects what I think--it is most likely to fall in the range of about 4 m k^2, +/- a million or so. But since so much of the ice is in such bad shape, there is a chance that with the right (=wrong) kind of weather pattern, we could have a much lower extent by the end of the season.

That is, there's a fat tail on the low end of the probability curve, imvho.
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Neven

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #63 on: June 14, 2015, 11:09:08 PM »
I've just posted a blog post on the ASIB, discussing the situation with regards to melt ponding during May: Melt Pond May 2015.

Here's Dr. David Schröder's prediction for the SIPN Sea Ice Outlook:



Quote
    Based on our simulated May melt pond fraction we predict a September 2015 mean ice extent for the Arctic of 5.1 +/- 0.5 Mill. km2. Our value is slightly lower than in 2013 (5.4 Mill. km2) and 2014 (5.3 Mill. km2), but considerably larger than in 2012 (3.6 Mill. km2). The attached 3 figures show the anomaly of May melt pond fraction in May 2015, May 2014 and May 2012 with respect to the mean over the period May 2006 to May 2015. Locations which show no correlation with the September ice extent are masked.

    In May 2012 there are positive anomalies of pond fraction with values between 0.5 and 2% above the last 10-year average, whereas in May 2014 negative anomalies between -0.2 and -1% occurred. In May 2015, the anomalies are mainly negative, but weaker than in 2014. The pond fraction does mainly depend on the atmospheric conditions in May and the pre-conditioning of sea ice (sea ice thickness, area fraction of thin ice).

    While the atmospheric conditions were quite "normal" in May in average, the ice is thicker in April 2015 in our model simulation compared to previous years. The increase in ice thickness and volume is also confirmed by the PIOMAS simulation: maximum ice volume in 2015: 24388 km3, in 2014: 23104 km3 and in 2011: 22677 km3.  The given uncertainty of our prediction of 0.5 Mill. km2 is mainly caused by ice drift during summer and the atmospheric conditions during June. Given the current situation we do not expect a new record minimum for Arctic summer sea ice in 2015.
The second half of June will have to see some serious melt ponding for 2015 to stay away from 2013 and 2014, but I'm not really seeing in the forecast right now. Yes, in the coming 2-3 days, but not after that, with low pressure taking over again.
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Neven

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #64 on: June 14, 2015, 11:17:11 PM »
Of the last ten years, 2 are off the top of the range and 3, including both the last two years, are in the top bin. If you curtailed it in a similar way at the bottom, the lowest bin available would be about 4.25 rather than 0.

Sure, but I'm not putting up this poll as an endeavour to create the perfect poll. I could put in 100 bins (have to put them all in by hand, because last year's bins weren't in my cache any longer), but in the end 80 of them won't be used. If you look at the results, maybe 3 out of a 106 people would've voted higher if they could have, but look at how many voted below 4.25.

That's because this forum attracts people that are worried about Arctic sea ice loss. In my view it's worrisome enough as it is, but some think it is even more worrisome and vote low. Practically no one here believes the Arctic will return to pre-2007 levels any time soon. So, that's what the poll is reflecting. I think it looks just fine for now, but given another melting season with seemingly low melting momentum and higher volume, I'm willing to add two more bins above 5.5 million km2.
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Michael Hauber

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #65 on: June 15, 2015, 02:49:09 AM »
You could always put a >5.5m at the top, and/or a <2m at the bottom (or whatever other numbers).
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Neven

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #66 on: June 15, 2015, 10:13:43 AM »
Yes, I used to do that, but that makes it difficult to calculate an average.
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Peter Ellis

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #67 on: June 15, 2015, 10:17:12 AM »
Eh, you'd be better off taking the median anyway.  That way you don't end up getting skewed by outlier votes (which are largely cast on political rather than scientific grounds).

DavidR

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #68 on: June 15, 2015, 11:22:31 AM »
Yes, I used to do that, but that makes it difficult to calculate an average.
Or you could ignore the outliers > 5.5,   and < 1.0; If you think that's more reasonable.  Anything above 5.5 is going to require exceptional  cold anyway and there is no sign of that.  We haven't had a decline less than 10 M km^2 (>> 4.59 minimum ) since 2006.
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Richard Rathbone

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #69 on: June 15, 2015, 01:17:18 PM »
Of the last ten years, 2 are off the top of the range and 3, including both the last two years, are in the top bin. If you curtailed it in a similar way at the bottom, the lowest bin available would be about 4.25 rather than 0.

Sure, but I'm not putting up this poll as an endeavour to create the perfect poll. I could put in 100 bins (have to put them all in by hand, because last year's bins weren't in my cache any longer), but in the end 80 of them won't be used. If you look at the results, maybe 3 out of a 106 people would've voted higher if they could have, but look at how many voted below 4.25.

That's because this forum attracts people that are worried about Arctic sea ice loss. In my view it's worrisome enough as it is, but some think it is even more worrisome and vote low. Practically no one here believes the Arctic will return to pre-2007 levels any time soon. So, that's what the poll is reflecting. I think it looks just fine for now, but given another melting season with seemingly low melting momentum and higher volume, I'm willing to add two more bins above 5.5 million km2.


If you are going to put a cut off within the region of reasonable predictions, at least make the top bin open ended. 5.55 would count as a success for Schroeder but wasn't possible to choose.


ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #70 on: June 15, 2015, 06:27:58 PM »
Did anyone get 2012 right for the June SIPN? excluding those who always go low?

Why exclude those who always go low? At this time of year when there is no reason not to go low is it such a crime to say so? IMO we are in an era where until the end of June, even mid-July at least, a) anything is possible... and b), the combination of unpredictable circumstances which will lead to a record low grows increasingly more likely every year. So my strategy is to assume the worst. I'm no spring chicken but I think it's very likely that I'll live long enough to be right it the end :)

It's not a crime to go low anymore than it is a crime for WTFWT to put in a high estimate every year. But I am interested in sea ice prediction more as a test of the underlying theory involved in the prediction method. So the information gained from a consistent high or low voter tells us about the bias in their judgment, not about ice conditions or the merits of any underlying theory.

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #71 on: June 15, 2015, 07:35:56 PM »
The forum effective prediction for September 2015 has remained largely unchanged despite the increase in votes since I first calculated it on7 June.

7 June, 71 votes, effective prediction 3.93M km^2.
9 June, 83 votes, effective prediction 3.83M km^2.
15 June (final), 106 votes, effective prediction 3.92M km^2.

Taking the set of votes as a series, I calculate the close average to be 4.04 M km^2, and a median of 4.00.

epiphyte

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #72 on: June 15, 2015, 09:14:48 PM »
Did anyone get 2012 right for the June SIPN? excluding those who always go low?

Why exclude those who always go low? At this time of year when there is no reason not to go low is it such a crime to say so? IMO we are in an era where until the end of June, even mid-July at least, a) anything is possible... and b), the combination of unpredictable circumstances which will lead to a record low grows increasingly more likely every year. So my strategy is to assume the worst. I'm no spring chicken but I think it's very likely that I'll live long enough to be right it the end :)

It's not a crime to go low anymore than it is a crime for WTFWT to put in a high estimate every year. But I am interested in sea ice prediction more as a test of the underlying theory involved in the prediction method. So the information gained from a consistent high or low voter tells us about the bias in their judgment, not about ice conditions or the merits of any underlying theory.

[fat-fingered this and posted before it was done... see the intended version lower down.]
« Last Edit: June 15, 2015, 11:36:41 PM by epiphyte »

Nick_Naylor

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #73 on: June 15, 2015, 10:06:22 PM »
So the information gained from a consistent high or low voter tells us about the bias in their judgment, not about ice conditions or the merits of any underlying theory.

True. A lot of us Newbie's don't have much to go on other than judgement combined with almost enough knowledge to be dangerous.

Maybe a separate poll of hero members or those who consider their estimates to be scientific would be helpful.

Nick_Naylor

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #74 on: June 15, 2015, 10:09:02 PM »
A lot of us Newbie's don't have much to go on other than judgement combined with almost enough knowledge to be dangerous.

I only mean to include myself in this group, of course.  :o

Tensor

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #75 on: June 15, 2015, 10:14:59 PM »
A lot of us Newbie's don't have much to go on other than judgement combined with almost enough knowledge to be dangerous.

I only mean to include myself in this group, of course.  :o

Yeah, I belong here also Nick, that's why I used my 22 sided die.   :P
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Neven

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #76 on: June 15, 2015, 11:10:17 PM »
Like Chris said, average prediction for all 106 votes is 3.92 million km2. Thanks for voting, everyone.
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epiphyte

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #77 on: June 15, 2015, 11:33:39 PM »
Did anyone get 2012 right for the June SIPN? excluding those who always go low?

Why exclude those who always go low? At this time of year when there is no reason not to go low is it such a crime to say so? IMO we are in an era where until the end of June, even mid-July at least, a) anything is possible... and b), the combination of unpredictable circumstances which will lead to a record low grows increasingly more likely every year. So my strategy is to assume the worst. I'm no spring chicken but I think it's very likely that I'll live long enough to be right it the end :)

It's not a crime to go low anymore than it is a crime for WTFWT to put in a high estimate every year. But I am interested in sea ice prediction more as a test of the underlying theory involved in the prediction method. So the information gained from a consistent high or low voter tells us about the bias in their judgment, not about ice conditions or the merits of any underlying theory.
The closest thing I have to a theory is that the collapse will be sudden, that it will take many of the models by surprise, because small uncertainties become much more significant around a tipping point, and that it's timing will be entirely at the whim of short-term weather conditions, for the same reason.

I've estimated consistently low in June since 2013 because I thought that conditions to put this to the test had been favorable up until that point. Does that reveal a bias in my judgement, or a problem with my theory, or both, or neither?

Well I can't predict the weather more than 5 days ahead, and neither can ECMWF or NOAA or anyone else, so if I judge that the early-season weather has been favorable and I have to make a prediction and my theory says that the outcome is a coin-flip...

 - if I predict high and the outcome is low and the weather remains favorable then not only am I wrong, but I didn't actually hold my theory up to test - I bet against it instead.
 - If I predict high and the outcome is high, then that tells us nothing about my judgement or my theory, regardless of the weather.
 - If I predict low and the weather remains favorable and the outcome is high, then my judgement and/or theory are wrong.
 - If I predict low and the weather becomes unfavorable and the outcome is high, then then that again tells us nothing about my judgement or my theory.
 - If I predict low and the weather remains favorable and the outcome is low then my judgement is ok, or at least not called into question. If the low outcome is a surprise to the models then my theory is looking pretty shiny too.

So given that I think that weather conditions up till early June have been consistent with a possible late-season collapse, the only prediction I can make that may hold my theory up to anything approaching a test is to go low.. This was the case in 2013, 2014 as well.  If I say low and the weather remains favorable to melt, my theory can be disproved, or at least sorely dented. That did not happen in 2013 or 2014.

If I had said high in 2013 or 2014 I would have been just dodging an opportunity to test the theory. I don't think that it's fair to contrast this with WTFWT - their position is based on ideology backed by cherry-picked data.

ChrisReynolds

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #78 on: June 16, 2015, 06:29:51 PM »
So the information gained from a consistent high or low voter tells us about the bias in their judgment, not about ice conditions or the merits of any underlying theory.

True. A lot of us Newbie's don't have much to go on other than judgement combined with almost enough knowledge to be dangerous.

Maybe a separate poll of hero members or those who consider their estimates to be scientific would be helpful.

Hero members only means people post a lot.

Those who consider their estimates to be scientific risks descending into self-regard and pompousness.

I think it is fine to have a all board vote with a variety of opinions. It is only for my own purposes that I discount the consistently high and low. Perhaps the only way to approach a low personal bias selection would be to only accept numerically formulated predictions, either statistical or modelling for which some level of demonstrable hindcast ability is demonstrated. But I don't favour that, it would leave too many people out of the fun. And this is a hobby, so it should be enjoyable.

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #79 on: June 16, 2015, 06:43:31 PM »
Epiphyte,

I'm not going to get into a discussion of the rapid collapse vs slow transition thing. The subject bores me now and I am happy for time to test my Slow Transition argument.

For other comments see my reply to Nick above.

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #80 on: June 16, 2015, 06:51:11 PM »
A lot of us Newbie's don't have much to go on other than judgement combined with almost enough knowledge to be dangerous.


If ever a truer word were spoken....I live in awe of the work that goes on here (too often unsung).

Just like Christmas, I wait with baited breath for my September sea-ice surprise.

Even after watching quietly for the last few years I still only have my gut feeling to go on. Sadly, my gut thinks curry and beer is a great combination, so I'll just go back to lurking under my rock.

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #81 on: June 16, 2015, 09:53:45 PM »
But I don't favour that, it would leave too many people out of the fun. And this is a hobby, so it should be enjoyable.

Exactly, this poll is mostly for fun, even though the subject isn't. The SIPN Sea Ice Outlook is more serious.
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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #82 on: June 17, 2015, 01:36:05 AM »
But I don't favour that, it would leave too many people out of the fun. And this is a hobby, so it should be enjoyable.

Exactly, this poll is mostly for fun, even though the subject isn't. The SIPN Sea Ice Outlook is more serious.

Huh? I was under the impression that this was a crowdsourcing-based prediction (of the sort that might become a submission into SIPN's project). Or did I misunderstand something?

If it isn't meant to be that, it might be worth creating!

epiphyte

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #83 on: June 17, 2015, 09:40:42 AM »
But I don't favour that, it would leave too many people out of the fun. And this is a hobby, so it should be enjoyable.

Exactly, this poll is mostly for fun, even though the subject isn't. The SIPN Sea Ice Outlook is more serious.

Yup. Wouldn't presume to weigh in on that one :)

.... but I would opine that sometimes standing back far enough to see the wood for the trees might not be the same as being unscientific.

Michael Hauber

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #84 on: June 17, 2015, 11:36:33 AM »
Those interested in the issues of making a prediction by crowd sourcing may find the wikipedia article Wisdom of the Crowd interesting.
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Neven

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #85 on: June 17, 2015, 12:55:24 PM »
Huh? I was under the impression that this was a crowdsourcing-based prediction (of the sort that might become a submission into SIPN's project). Or did I misunderstand something?

If it isn't meant to be that, it might be worth creating!

I've always said that if you combine this poll with the one at WUWT, you might get a realistic number to submit to the SIO. But I'm not going to ask them.  ;D
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Nightvid Cole

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #86 on: June 25, 2015, 04:26:16 AM »

Richard Rathbone

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #87 on: June 25, 2015, 03:32:09 PM »
SIPN report for June is now out:

http://www.arcus.org/sipn/sea-ice-outlook/2015/june

Wadhams is predicting virtually ice free (a smidge under 1), but there's a pretty strong consensus around 5. June seems if anything to have been on the low melt side (CT may have fallen off a cliff but according to Wipneus calcs its area hasn't), but waiting to see if PIOMAS continues its year on year increases to decide if I actually want to make use of that space at the top in July that I bugged Neven about not providing this month. ;)

OSweetMrMath

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #88 on: June 26, 2015, 03:39:58 AM »
SIPN report for June is now out:

http://www.arcus.org/sipn/sea-ice-outlook/2015/june

Interesting. I considered submitting my predictions to SIPN last year. My method is at least as rigorous as some of the other statistical and heuristic methods. But my predictions closely tracked the group median, so I didn't bother because my prediction seemed redundant. (At least, this is my recollection. I haven't verified this.) I turned out to be as wrong as everyone else when the melt in July turned out to be less than predicted.

This year my prediction is somewhat below the group median. Do they know something I don't know? Is my methodology more accurate than the collected approaches of the other predictions? Time will tell.
« Last Edit: June 26, 2015, 05:21:38 AM by OSweetMrMath »

Michael Hauber

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #89 on: June 26, 2015, 04:12:50 AM »
The two predictions that caught my eye were Kay et al, where an informal pool of 30 climate scientists predicted 4.39 m +/- 0.45.  They claim that the pool has been running for 8 years and has been quite accurate in the past.

At the other end is Bosse with 5.6 +/- 0.4.  This is a statistical estimation using the PIOMAS volume at the start of the melt season, and a measure of the ocean heat content from last summer.  Ocean heat would appear to be very important, and something that doesn't seem to come up a lot.  I'm not sure how accurate the measurements that are available, and how well the value for summer carries over through the winter, but this prediction seems to be a hint that there may be a shortage of sub-surface ocean heat content this summer.
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Richard Rathbone

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #90 on: June 26, 2015, 12:55:31 PM »
Is there any product based on ARGO that could have been used by Bosse? Otherwise I'd assume its PIOMAS again. That 0.4 is a single standard deviation so its not really all that much above the other methods clustered around 5.

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #91 on: September 16, 2015, 08:50:23 PM »
how well did this forum do on the June poll as compared with the announced final of 4.41?
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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #92 on: September 16, 2015, 09:00:44 PM »
Others' predictions:

Quote
@NASA_ICE: Arctic sea ice has reached its annual minimum extent and it's the 4th lowest on record. http://t.co/M4ermZVAFI http://t.co/cVFhYcn6vj

https://twitter.com/nasa_ice/status/643856316914663426

Quote
@melsom62: At 4.41mill.km2 the winner from the June outlook (http://t.co/JPggb0mcHV) is @metoffice ! @NASA_ICE @ClimateOfGavin http://t.co/42LVmGgOS8

https://twitter.com/melsom62/status/644142237270605824
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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #93 on: September 16, 2015, 11:47:56 PM »
how well did this forum do on the June poll as compared with the announced final of 4.41?
The poll is for the September Average Minimum so the final figure is likely  to be in the 4.5-4.75 bucket, which  means that  most  of us went low. 

However we were mostly  within a single standard deviation of the result ( ~ 600K) which isn't too bad.
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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #94 on: September 17, 2015, 01:07:42 AM »
Like DavidR says, the number put out by the NSIDC is for the daily minimum, whereby they add to the confusion, because with the NSIDC it has always been about the September monthly average.

Either way, in the August poll topic I had posted this image showing all the polling results this year:



The median and average are too low, but the bin that received most votes has been pretty much on the ball.
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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #95 on: September 17, 2015, 07:48:27 AM »
Like DavidR says, the number put out by the NSIDC is for the daily minimum, whereby they add to the confusion, because with the NSIDC it has always been about the September monthly average.

Either way, in the August poll topic I had posted this image showing all the polling results this year:



The median and average are too low, but the bin that received most votes has been pretty much on the ball.

The median discards somehow the tail estimates, it is not far either. Speaks well of the forum. In 2013 it was not so scientific but more passionate, lets say, so it means folks as myself are learning bits. Thx for the polls, these are instructive too.

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Re: NSIDC 2015 Arctic SIE September minimum: June poll
« Reply #96 on: September 22, 2015, 10:54:01 AM »
Like DavidR says, the number put out by the NSIDC is for the daily minimum, whereby they add to the confusion, because with the NSIDC it has always been about the September monthly average.

Either way, in the August poll topic I had posted this image showing all the polling results this year:



The median and average are too low, but the bin that received most votes has been pretty much on the ball.

The median discards somehow the tail estimates, it is not far either. Speaks well of the forum. In 2013 it was not so scientific but more passionate, lets say, so it means folks as myself are learning bits. Thx for the polls, these are instructive too.
Arctic temperatures, particularly SST's , were much lower than recent years in both May and August.  Melt  was much lower than expected in June and Sept. 

I  have a theory that SSTs are a good predictor of the melt in the following month so its not that  surprising that the June and August  predictions were lower and the July  one much  close to  reality given the very  low melt in June and the big melt in July.

Standard deviation of melt  is still about  500K even at the beginning of August so anything close is a lot of luck and a little bit  of experience.
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