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What will the NSIDC 2013 Arctic SIE September minimum be?

More than 5.0 million km2
0 (0%)
Between 4.75 and 5.0 million km2
1 (1.6%)
Between 4.5 and 4.75 million km2
0 (0%)
Between 4.25 and 4.5 million km2
4 (6.6%)
Between 4.0 and 4.25 million km2
4 (6.6%)
Between 3.75 and 4.0 million km2
10 (16.4%)
Between 3.5 and 3.75 million km2
10 (16.4%)
Between 3.25 and 3.5 million km2
6 (9.8%)
Between 3.0 and 3.25 million km2
11 (18%)
Between 2.75 and 3.0 million km2
9 (14.8%)
Between 2.5 and 2.75 million km2
0 (0%)
Between 2.25 and 2.5 million km2
0 (0%)
Between 2.0 and 2.25 million km2
1 (1.6%)
Between 1.75 and 2.0 million km2
2 (3.3%)
Between 1.5 and 1.75 million km2
1 (1.6%)
Between 1.25 and 1.5 million km2
0 (0%)
Between 1.0 and 1.25 million km2
0 (0%)
Between 0.75 and 1.0 million km2
1 (1.6%)
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 (1.6%)

Total Members Voted: 57

Voting closed: July 20, 2013, 11:24:49 AM

Author Topic: NSIDC 2013 Arctic SIE September minimum: July poll  (Read 73640 times)

BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #50 on: July 16, 2013, 04:16:33 PM »
A drop of 126.2k on the latest update, with the average daily loss over the last 7 days remaining above 100k/day, at 113k/day.
We're back to 4th lowest on record, but will need to maintain a loss rate of over 75k/day for the remainder of the month in order to close in on the 2007, 2011 and 2012 average (the 2011 loss rate falls to one of the lowest recorded in the 10 days of the month though)

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Oyvind Johnsen

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #51 on: July 16, 2013, 04:27:59 PM »
Headed for 2nd lowest by the end of July...

James Lovejoy

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #52 on: July 16, 2013, 10:31:04 PM »
I've stuck with 4 to 4.25.  I think that the cool spring & early summer have given the ice a reprieve.

I have no confidence in my guess.  I think that  the ice is in poor enough condition that a few weeks of favorable melting weather could really melt it down.

Oyvind Johnsen

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #53 on: July 17, 2013, 08:28:31 AM »
I voted for 3.75-4.0, as in May and June. After the exceptional loss last year, I expected a regression to the mean (whatever that mean may be...) of some kind. Probably a bit less than from 2007 to 2008. It was and is just a guess, but as the melt season has turned out so far, ìt still seems a quite likely result.

BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #54 on: July 17, 2013, 05:32:21 PM »
A drop of 111k today. This takes us past the 2 million km2 loss mark for July so far.
Just 87.9k/day is now needed to record the largest July extent drop on record.
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #55 on: July 17, 2013, 07:45:36 PM »
I feel like I am on a hill in with a group of people, and we pushed an unmanned vehicle to get it rolling down the hill in neutral.  Then.....we watch and place bets on when it will crash and burn at the bottom of the hill.  We all KNOW that basic science will "do its duty" in pulling the car downhill....it's just a matter of time.

Same thing with the Arctic ice sheet, and the NSIDC measurements.  It's only a matter of time.  Just as the laws of gravity can't be repealed....neither can the laws of physics that affect the climate and the ice sheet.

The ice is in "bad shape"....and heading downhill.  None of the factors that affect it over time....are improving.  Albedo is moving lower.....more particles from forest fires are in the air.....oceans are warming up.....China/India/etc are still growing and adding more "fuel to the fire" (literally:).....and the car is speeding up.

The amazing thing to me is that, just like the financial markets had Goldman Sach's, Bernie Madoff, Morgan Stanly and others that were willing to lie and deceive the public and investors about the financial shenanigans that was going on.........we also have people like Inhoffe, FOX, Watts, Bastardi and others who are willing to (1) lie, (2) mis-inform, (3) deceive, or (4) avoid facts like they were the plague.

Humanity has a LONG way to go until we are even on the road to "intelligent life".

 
FOX (RT) News....."The Trump Channel.....where truth and journalism are dead."

Bob Wallace

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #56 on: July 17, 2013, 08:22:47 PM »
We're pre-wired to deal with near term dangers and work for short term gain.

The stuff way down the road is difficult for us.  As the present pain of climate change builds we're increasing our efforts to deal with the causes.


BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #57 on: July 17, 2013, 09:12:07 PM »
New NSIDC update, discussing the recent rapid melt and the regional extent variation.

A change of pace
Sea ice extent retreated fairly rapidly through the first two weeks of July as a high pressure cell moved into the central Arctic, bringing warmer temperatures over much of the Arctic Ocean. Ice extent remains below average on the Atlantic side of the Arctic, and is near average to locally above average in the Beaufort and Chukchi seas and along much of the Eurasian coast.



The rest is here http://nsidc.org/arcticseaicenews/2013/07/a-change-of-pace/
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BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #58 on: July 18, 2013, 06:31:29 PM »
A drop of 159.9k today, taking us to 350k off the 07, 11 and 12 average, and 83k below the average of the last 5 years.



« Last Edit: July 18, 2013, 07:38:16 PM by BornFromTheVoid »
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BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #59 on: July 19, 2013, 04:18:19 PM »
A 94.1k drop yesterday, taking us to 346.8k of the 07, 11 and 12 average, and just 80.8k away from 2007.
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BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #60 on: July 20, 2013, 11:49:53 PM »
A rather surprising increase on the latest update of 29k.
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #61 on: July 21, 2013, 02:51:08 PM »
A rather surprising increase on the latest update of 29k.
BFTV,
With the patterns for wind and sea level pressure I hope we can attribute it to spreading and then perhaps as they shift directions compacting will cause some large daily extent losses.

I do appreciate your updates.
« Last Edit: July 26, 2013, 03:11:01 PM by JackTaylor »

BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #62 on: July 21, 2013, 08:18:49 PM »
Update for the week to July 20th

The current 1 day extent is 7,820,740km2,  while the 5 day mean is on 7,910,644km2
 
The daily anomaly (compared to 79-11) is at -1,292,420km2, a decrease from -1,342,190km2 last week. The anomaly compared to the 07, 11 and 12 average has increased from +432,870km2 last week to 492,600km2 this week. We're currently 5th lowest on record, the same as last week.
 
The average daily loss over the last 7 days was 81.2k/day, compared to the long term average of 88.3k/day, and the average of the last 5 years of 89.6k/day.

The average long term loss over the next week is 85.6k/day, with the average of the last 5 years being 90.5k/day.

The extent drop so far in July is the third largest on record at 2,328,110km2, with 2011 in second (2,336,270km2) and 2007 in first (2,470,070km2)
An average daily loss of 80.5k/day is needed for the remainder of the month to achieve the largest July extent drop on record.



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BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #63 on: July 22, 2013, 04:31:39 PM »
A drop of 232k on the latest update, 3rd largest daily drop this melt season. Takes us back below the average of the last 5 years, and into 4th lowest on record for the time of year
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #64 on: July 27, 2013, 04:06:35 PM »
The last few days have seen the melt slow, with the rolling 7 day loss below the 81-10 average for the last 3 days.
The latest drop was 112k.

The 07, 11 and 12 average loss from the 26th to the 31st is just 56k/day, so this is a good opportunity to make up some of the 460k that we're behind.
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #65 on: July 27, 2013, 04:58:51 PM »
The last few days have seen the melt slow, with the rolling 7 day loss below the 81-10 average for the last 3 days.
The latest drop was 112k.

The 07, 11 and 12 average loss from the 26th to the 31st is just 56k/day, so this is a good opportunity to make up some of the 460k that we're behind.

Is the melt slowing or is the cyclone dispersing ice into the Chukchi and ESS?

BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #66 on: July 27, 2013, 05:21:29 PM »

Is the melt slowing or is the cyclone dispersing ice into the Chukchi and ESS?

The average daily drop over the last 10 has been below the long term average, so while the dispersion from the storm is likely playing it's part, I think there has been a slight slow down anyway.
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BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #67 on: July 28, 2013, 04:36:35 PM »
Update for the week to July 27th

The current 1 day extent is 7,274,800km2,  while the 5 day mean is on 7,387,676km2
 
The daily anomaly (compared to 79-11) is at -1,239,170km2, a decrease from -1,292,420km2 last week. The anomaly compared to the 07, 11 and 12 average has increased from +492,600km2 last week to +517,153km2 this week. We're currently 6th lowest on record, up from 5th lowest last week.
 
The average daily loss over the last 7 days was 78.0k/day, compared to the long term average of 85.6k/day, and the average of the last 5 years of 90.5k/day.

The average long term loss over the next week is 82.9k/day, with the average of the last 5 years being 73.0k/day.

The extent drop so far in July is the third largest on record at 2,874,050km2, with 2007 in second (3,161,190km2) and 2009 in first (2,173,990km2)
An average daily loss of 125.2k/day is needed for the remainder of the month to achieve the largest July extent drop on record.





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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #68 on: July 29, 2013, 03:54:18 PM »
Drop of almost 150k. At 7.12499 Mm2 NSIDC is now below IJIS for the first time this season.

BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #69 on: July 31, 2013, 04:06:45 PM »
An increase of 28k for the 29th and a drop of 2k for the 30th keeps the plateau going.

We're now 6th lowest on record, and could potentially finish the month above 2005
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BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #70 on: August 01, 2013, 05:05:47 PM »
A small drop on the latest update, 54.6k, so we finish the month as 6th lowest.

The 7 day loss up to the 30th, was 305k, only the 4th year to record a 7 day loss of below 310k.
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Wipneus

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #71 on: August 03, 2013, 04:00:59 PM »
And a  110k9 drop (after a 150k yesterday). On the move again!

BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #72 on: August 03, 2013, 04:27:27 PM »
That's 262k dropped in the last 2 days.

The 7 day extent drop is still well below average though, just 460k compared to 81-10 average of 618k.
The long term extent loss rate drops rapidly during August though, with the 7 day loss in a weeks time down to 465k, and down to 258k by months end.
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #73 on: August 04, 2013, 07:16:27 AM »
If you look at NSIDC, and JAXA, and CT, you could well be looking at different planets.

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #74 on: August 04, 2013, 04:31:10 PM »
And another 155k.

Now explain that!

BornFromTheVoid

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #75 on: August 04, 2013, 04:46:10 PM »
And another 155k.

Now explain that!

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #76 on: August 04, 2013, 04:58:09 PM »
For NSIDC we've passed 2009 and moved into 5th place.  Woo hoo!

If the next week sees a lot of ice loss, we could pass 2011 too.  But the remaining three years (2012, 2010, and 2007) should be safe for the next week. 

On the other hand, if things slow down suddenly, we could fall behind 2005, 2008, and 2009. 

So I guess a week from now we could be anywhere from 4th to 8th place....

AndrewP

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #77 on: August 24, 2013, 02:51:35 AM »
It appears that NSIDC will finish near 5 million for the year. This sea ice blog will have the worst prediction of all predictions submitted to ARCUS in July. It is also likely the worst July prediction in several years. The end result will likely be about 1 million sq km outside the confidence interval and nearly 2 million above the mean prediction.

 Given we began this year with volume similar to 2010, a minimum near 2010 was fairly predictable. There is an unfortunate bias and group think mentality on this forum which biases even some of the more knowledgeable posters.


Vergent

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #78 on: August 24, 2013, 07:02:28 AM »
It appears that NSIDC will finish near 5 million for the year. This sea ice blog will have the worst prediction of all predictions submitted to ARCUS in July. It is also likely the worst July prediction in several years. The end result will likely be about 1 million sq km outside the confidence interval and nearly 2 million above the mean prediction.

 Given we began this year with volume similar to 2010, a minimum near 2010 was fairly predictable. There is an unfortunate bias and group think mentality on this forum which biases even some of the more knowledgeable posters.



AndrewP(skierinvermont),

On March 7, skierinvermont(AndrewP) said;

Quote
4.2, 2.7, 3.7 respectively
 
confidence interval for SIE of 3.3-5.0

SIE,SIA, Volume

http://www.americanwx.com/bb/index.php/topic/39634-guess-the-2013-sie-sia-and-volume-minimum/

Post #3(If its gone, he erased it.)

You gave people 250k bins in your pole, but give yourself 1,700k wiggle room on your own guess, covering virtually the whole range of the blog predictions. Then you come here and insult the blog and forum for having opinions in the same range as you guessed. Shame on you.

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AndrewP

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #79 on: August 24, 2013, 07:46:51 AM »
Shame on me for estimating confidence intervals for my prediction? What new nonsense is this?

Given the cold weather this year which could not have been known in advance, I would expect the end result to fall on the high side of most confidence intervals issued in June. What is so astonishing about this forum is that the end result will be nearly 2.5 million above the mean, and even providing for reasonable 95% confidence intervals of +/- 1 million, nearly 1.5 million sq km above the high end of a 95% confidence interval.

Most scientific predictions of sea ice generally have confidence intervals of +/- 1 million because summer weather is difficult to predict. When the known variables driving minimum extent are factored in it is generally possible to predict within this 2 million sq km range. I believe I have successfully predicted the minimum within 1 million sq km for 7 years now. What is apparent is that this forum does not understand or ignores these known variables (primarily ice volume and weather climatology which both pointed to a minimum near 2010). Which has resulted in an error so large it would invalidate even the most generous confidence intervals.
« Last Edit: August 24, 2013, 07:54:36 AM by AndrewP »

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #80 on: August 24, 2013, 08:04:13 AM »
Shame on me for estimating confidence intervals for my prediction? What new nonsense is this?

Given the cold weather this year which could not have been known in advance, I would expect the end result to fall on the high side of most confidence intervals issued in June. What is so astonishing about this forum is that the end result will be nearly 2.5 million above the mean, and even providing for reasonable 95% confidence intervals of +/- 1 million, nearly 1.5 million sq km above the high end of a 95% confidence interval.

Most scientific predictions of sea ice generally have confidence intervals of +/- 1 million because summer weather is difficult to predict. When the known variables driving minimum extent are factored in it is generally possible to predict within this 2 million sq km range. I believe I have successfully predicted the minimum within 1 million sq km for 7 years now. What is apparent is that this forum does not understand or ignores these known variables (primarily ice volume and weather climatology which both pointed to a minimum near 2010). Which has resulted in an error so large it would invalidate even the most generous confidence intervals.

And what, AndrewP, is your point?  Are you here simply to insult us, or perhaps, *Just* perhaps, you'd care to support your assertions with some fact, and possibly provide us with something useful, rather than just touting your superiority?

And just how is it we are supposed to see evidence that you correctly predicted previous minima?

Please give us a dose of something other than your ego?
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Vergent

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #81 on: August 24, 2013, 09:32:59 AM »
jdallen,

he is just a troll.

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slow wing

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #82 on: August 24, 2013, 12:34:15 PM »
Most scientific predictions of sea ice generally have confidence intervals of +/- 1 million

Yep he is a troll, spouting nonsense.
« Last Edit: August 24, 2013, 12:46:34 PM by slow wing »

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #83 on: August 25, 2013, 07:55:10 PM »
No, he actually has a valid point.

The only thing Andrew seems to fail to take into account is that from the very modelling system he used to state "Given we began* this year with volume similar to 2010, a minimum near 2010 was fairly predictable." shows that unusual behaviour is to be expected.

PIOMAS average thickness in April is now around 2m thick.



And it is around this thickness that open water formation efficiency jumps massively.



Now I presume that PIOMAS is being used and that 'began' refers to around 30 May, because volume before then, e.g. 30 April, was actually below previous years.

Therefore the earliest one might have made an argument based on volume was early June when the June data was released from PIOMAS.

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #84 on: August 26, 2013, 02:19:32 AM »
He's trolling.

There may be a valid point buried in there somewhere. However, he is berating the forum for allegedly being off by more than 2 sigma, where he himself has chosen the sigma (uncertainty) and with a justification that is dubious at best. Participants in the poll weren't required to state an uncertainty.

  The other point he deliberately ignores is that most competent experimental scientists will anyway have been off by more than 2 sigma on at least some occasions, through no fault of their own. Sometimes nature does that to you!

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #85 on: August 26, 2013, 02:30:58 AM »
Andrew
Hindsight is 20/20 but you've been posting here since early March. Why berate the posters here for not jumping on those positing low guesstimates when you weren't leading the charge back then yourself?
We'll soon have a long winter to examine the error of our ways, and we're about to finish with the melt season when your own guesses could have been put to the test. Why would you begin your rant at a time thats too late for your ideas to have be considered and yet too early for others to be gin to reappraising their votes?
It's easy to claim that you had all the answers by June, but if you did why didn't you explain it to us back when it would have been news?
Terry

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #86 on: August 26, 2013, 08:11:34 AM »
Andrew
Hindsight is 20/20 but you've been posting here since early March. Why berate the posters here for not jumping on those positing low guesstimates when you weren't leading the charge back then yourself?
We'll soon have a long winter to examine the error of our ways, and we're about to finish with the melt season when your own guesses could have been put to the test. Why would you begin your rant at a time thats too late for your ideas to have be considered and yet too early for others to be gin to reappraising their votes?
It's easy to claim that you had all the answers by June, but if you did why didn't you explain it to us back when it would have been news?
Terry

I have frequently made predictions for higher SIE and SIA since March and provided my reasoning. I have posted about just how impossible and unjustifiable by any reasonable rational the near 2012 (and much lower) predictions were. You may have missed these posts. Most of my posting on this forum occurred in the June and July SIA polls. Also considerable posting on AMWX.

For example, here is a post of mine on June 19th in the June poll thread where I stated that by every objective measure (SIA, SIV) the ice was more similar to 2009 than 2012. While at the time I did not think that the ice was quite as good as 2009, with good weather it was within striking distance. And as you know, we are now in a dog race with 2009.


Funny how this forum was all about positive feedbacks to open ocean, and the importance of an early start to the melt season. Now when we have a slow start to the melt season and the associated feedbacks, the new theory is that the ice is just so thin we're just going to drop off a cliff anyways (and never mind the fact that not only is the loss in area slower this year, thickness is also significantly greater as well).

Unbelievable that most people on this forum are predicting SIA less than last year when by every objective parameter (SIA, PIOMAS) the ice pack is much more similar to 2009 than 2012. There is not a single objective criterion for predicting less SIA than last year.



And again on June 20th, I point out that not only were SIA and SIV doing considerably better than 2012, but the weather of 2012 was unlikely to repeat.

The final minimum will be primarily governed by 3 factors:

1) weather (which is unpredictable)

2) thickness (which is greater than last year)

3) early season area loss an initiation of positive feedbacks (there is much more area than last year at this time)


Thus, all relevant factors point to a higher minimum than last year. Even if you go searching for irrelevant minor factors like snowcover in AK, there is still no reason to predict a lower minimum than last year.


June 7th:

It is still possible to get cooler weather in the arctic and positive feedbacks have not yet created perma-warmth in the arctic. A significant portion of the warmth the last 5 of the last 6 years has been due to weather patterns unrelated to climate change or positive feedbacks.  2009 demonstrated this, and 2013 is on its way to demonstrating this as well. I have a feeling some of the predictions in this thread will end up looking just as silly as the WUWT predictions do most years.

If volume is running above the previous 3 year average, why the hell would you predict area over 1 million sq km lower than the 3 year average? That's not to mention that area is also running above the previous 3 year average, which means positive feedbacks will be delayed as well.


June 7th:

3.0-3.25 (SIA prediction)

could be anywhere between 2.25 and 4.


IIRC Chris Reynolds was predicting aggressive melt by this time of year due to the high proportion of FYI. That has failed to materialize, and PIOMAS is running above several recent years. Given volume is on the high side of the 2010-2012 period, an average of those three years, or perhaps a bit higher, would seem like a reasonable prediction.




So again to summarize these are the three primary reasons that a prediction of SIA in the low 3s +/- 800k, and SIE in the mid 4s +/-800k was possible by early June. I repeated these three reasons often and emphatically.

1. SIV was in a tie with 2010

2. SIA was the highest since 2004.

3. The weather for the remainder of the summer was unlikely to be as hostile as it was in 2012. 2012 was an outlier, even in the new modern climate.
« Last Edit: August 26, 2013, 08:41:09 AM by AndrewP »

werther

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #87 on: August 26, 2013, 08:54:31 AM »
Thanks, Andrew.
You made your point. Enjoy yourself and show some restraint until the pro's and esteemed fellow bloggers come out with their analysis.

jdallen

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #88 on: August 26, 2013, 09:06:56 AM »
Ok, Andrew, we have established that you had a better prediction in June than many of us, and attempted to persuade people.

My biggest problem was you excoriating many who arrived at their lower predictions by some fairly careful reasoning, *and* who might have been far closer with just slightly different conditions.

How many people last year, in June, were within 2 million KM2 of the final?

My point is, there is a certain unpredictability here which is not unmaking to stock market behavior.  You can track fundamentals, and use the algorithm successfully every time, except when it isn't... And the forces moving a stock, or the market diverge radically from predicted behavior. People made guesses from the models they imagined.  This year, yours was correct. I do not think your assertions about *most* people on this blog were remotely fair, however correct your own conclusions were regarding the ice. That is what is making people bristle, and if you really want to be persuasive, I suggest you start by not insulting your audience. 

To vergent and everyone else... Just let it go.  You don't have anything you have to prove about your intellect.

Lets get back to understanding what we see, eh?
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #89 on: August 26, 2013, 09:19:13 AM »
Ok, Andrew, we have established that you had a better prediction in June than many of us, and attempted to persuade people.

My biggest problem was you excoriating many who arrived at their lower predictions by some fairly careful reasoning, *and* who might have been far closer with just slightly different conditions.

How many people last year, in June, were within 2 million KM2 of the final?

My point is, there is a certain unpredictability here which is not unmaking to stock market behavior.  You can track fundamentals, and use the algorithm successfully every time, except when it isn't... And the forces moving a stock, or the market diverge radically from predicted behavior. People made guesses from the models they imagined.  This year, yours was correct. I do not think your assertions about *most* people on this blog were remotely fair, however correct your own conclusions were regarding the ice. That is what is making people bristle, and if you really want to be persuasive, I suggest you start by not insulting your audience. 

To vergent and everyone else... Just let it go.  You don't have anything you have to prove about your intellect.

Lets get back to understanding what we see, eh?

People provided reasons for a 2012 (or lower) minimum, but they were not at all logical, complete+comprehensive or valid.

Given the high SIV and SIA by early June, it would have taken a far more hostile weather pattern than 2012 to bring us close to 2012. A 2007 weather pattern might have done it, but by early to mid June it might have been too late even with such a pattern and a 2007 weather pattern is highly unlikely. Even a 2012 weather pattern was unlikely. Remember, part of the reason 2007 was so awful is the pattern developed in May and had already preconditioned the ice, caused very low SIA, and initiated positive feedbacks. Simply none of these were present in early or mid June 2013.

You are trying to argue that 'my model' got lucky this year. Luck had nothing to do with it. In fact, the surprisingly cold weather was 'unlucky' and made my estimates too low. Had we had a more average summer, my estimates would likely have been more accurate.

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #90 on: August 26, 2013, 09:49:55 AM »
Andrew,

I don't think your prediction was totally lucky, there is an element of luck regards weather over the rest of the season, as the truncation of a CT Area drop after 26 July indicated. That applies to my early July prediction. I suppose you will still say I called it too late I was tempted to call a lower around the same time as the posts you quote (20 June) once it seemed to me that the CT Area cliff was over, but decided to wait until all of June's data was in.

However if in March you were predicting a 'recovery' in the sense of higher extent/area than last year - that was lucky. Here is why:

At the time PIOMAS volume was about the same as 2012, but the thickness profile was thinner, as I have shown you previously. You had no way of telling what the spring (May-June) volume loss in PIOMAS would have been, and this period's melt plays a strong role in summer volume loss post 2010. You had no way of knowing whether the summer pattern and its attendant 'dipole anomaly' would appear in 2013 - as things have turned out it didn't.

If you think you had a means of determining either of these in advance I would be very interested (not being infantile here - genuinely interested). I also recall us discussing correlation with end of season minimum and how it is very low before June, although I don't recall you coming back to show how I was wrong.

I do appreciate the flack you're drawing and don't think it is warranted. I've drawn similar flack and have decided some time ago not to challenge the bias you are arguing against. I think it is telling that the blog posts I write which contain words like 'crash' draw in far more traffic than the less excitingly entitled, but in my opinion more important posts I have written. All I have to do to 'go viral' is write posts implying an impending disaster - that aren't too complex.

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #91 on: August 26, 2013, 09:57:22 AM »
Anyway, I didn't come here to post the above, I came here to post the below...



Apologies for an image, but rendering a table like that here is not a prospect I relish.

That's derived from the May to August votes for NSIDC Extent and CT Area. The first column (May) is the actual number of votes for May, the following columns (June to Aug) are the differences from the first column (May). 'Current' values are the latest values for the respective series. Totals are the total votes for each month.

There has been a shift upwards, although this is later and possibly less high than some would argue is reasonable.

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #92 on: August 26, 2013, 05:29:20 PM »




Hurrah! Recovery!

Vergent

Edit: Equilibrium!
Edit: adding 2011(sorry about the miss match date, that's as far back as it goes)
« Last Edit: August 26, 2013, 05:57:11 PM by Vergent »

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #93 on: August 26, 2013, 06:09:25 PM »
... And with TOPAZ, Vergent captures questions I have been posing...

What is the meaning of the signal we are seeing with increased extent and area?

Considering the dispersion and poor quality of the ice, is increased extent actually a positive signal?

Is SIV really recovering in view of reporting like TOPAZ, which reports year over year significantly decreased sea ice thickness across the entire basin?

@ChrisReynolds - thank you for capturing so eloquently what I was trying to get across to AndrewP about making predictions regarding the arctic this year.
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #94 on: August 26, 2013, 06:51:25 PM »
JDAllen,

Actually the information kind of falls between both camps - yes there has been a shift towards higher predictions as time has gone on in response to conditions. But this shift has been late and while we will have to await the actual minimum August predictions do seem to be on the low side.

On a related matter, I've done a blog post that shows where my prediction is, and outlines why I already think that at worse it will be a very near miss, although I wouldn't have posted this unless I was very confident of a success.
http://dosbat.blogspot.co.uk/2013/08/prediction-update.html

JDAllen / Vergent,

From total volume as of the end of July PIOMAS doesn't show record thin ice / low volume. PIOMAS is backed up by intercomparison with other data, is TOPAZ? As I've shown in the last few days, PIOMAS captures the distribution of thicker MYI very well when compared with QuikScat, I've previously shown the same thing with ASCAT and the DAM.

Why then take TOPAZ as a better indicator than PIOMAS?

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #95 on: August 26, 2013, 08:25:22 PM »
Andrew,

I don't think your prediction was totally lucky, there is an element of luck regards weather over the rest of the season, as the truncation of a CT Area drop after 26 July indicated. That applies to my early July prediction. I suppose you will still say I called it too late I was tempted to call a lower around the same time as the posts you quote (20 June) once it seemed to me that the CT Area cliff was over, but decided to wait until all of June's data was in.

However if in March you were predicting a 'recovery' in the sense of higher extent/area than last year - that was lucky. Here is why:

At the time PIOMAS volume was about the same as 2012, but the thickness profile was thinner, as I have shown you previously. You had no way of telling what the spring (May-June) volume loss in PIOMAS would have been, and this period's melt plays a strong role in summer volume loss post 2010. You had no way of knowing whether the summer pattern and its attendant 'dipole anomaly' would appear in 2013 - as things have turned out it didn't.

If you think you had a means of determining either of these in advance I would be very interested (not being infantile here - genuinely interested). I also recall us discussing correlation with end of season minimum and how it is very low before June, although I don't recall you coming back to show how I was wrong.

I do appreciate the flack you're drawing and don't think it is warranted. I've drawn similar flack and have decided some time ago not to challenge the bias you are arguing against. I think it is telling that the blog posts I write which contain words like 'crash' draw in far more traffic than the less excitingly entitled, but in my opinion more important posts I have written. All I have to do to 'go viral' is write posts implying an impending disaster - that aren't too complex.

Oh I don't think anything close to accurate could have been predicted in March. I predicted 4.2 (3.3-5.0) SIE, and 2.7 SIA. Both are bumps from the previous year, but not by much. Both would be 2nd worst all time. I will be lucky if we finish in my MOE for SIE. But I do believe a small bounce over 2012 was the best central estimate at the time, and in retrospect that looks a lot better than the near 2012 or new record predictions.

Perhaps most telling would be a comparison of our volume predictions. I predicted 3.7. I don't see a # in your blog post, but you suggest using the post 2010 thinning profiles which would yield 3.88, 3.67, and 3.43. But then you suggest that it might be more melt this year and that you lean lower. I'm trying to parse your thinking here, but it sound like you were thinking very close to 2012 at 3.3 or 3.4 if you were forced to give a #. Possibly lower I'm not sure.

So we were similar, with you being about .3-.4 km3 lower. I think the difference in our SIA, SIE, and SIV predictions can primarily be ascribed to me being more confident that 2010-2012 represents a skewed climatology of our current climate. I believe that those were 3 exceptionally warm, hostile years. The sample size of 3 was not and is not enough to convince me that that was the new normal. While I leaned heavily towards a 2010-2012 climatology (or a 2007-2012 weather-only climatology ignoring ice differences pre-2010), I hedged slightly against the possibility of a cooler year because of the small sample size.

I want to emphasize that this slight hedge is not remotely similar to the belief of WUWT-types that a recovery is imminent, that 2007,2008, 2010-2012 were all flukes, and that every year will be like 2009, 2013 or colder. I am simply trying to make a subjective recognition that 2010-2012 is a small sample size, and the possibility exists that we will still get years like 2009 (or even less hostile).

Next year, barring some massive recovery in PIOMAS, I will be predicting very similar #s for SIA, SIE, SIV as I did this year (2.7,4.2,3.7), which will all be much lower than the result this year. No recovery.


On a side note, you say the 2013 thickness profiles were thinner but I don't see how this is possible. Both 2012 and 2013 had similar volume and area in March, which means thickness must have been the same as well. Personally, I don't think the distribution matters much. If it is centralized it will protect the ice late season, if it is peripheral then it will delay the start of melt season and positive feedbacks. 2013, 2012, and 2011 all had similar volume in March.

Thus, a good starting point for SIA, SIV, and SIE predictions was an average of 2011 and 2012. If you hedge a little against cooler weather, as I did, you could lean a little closer to 2011, as I did.
« Last Edit: August 26, 2013, 08:35:53 PM by AndrewP »

jdallen

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #96 on: August 26, 2013, 08:30:35 PM »
JDAllen,

Why then take TOPAZ as a better indicator than PIOMAS?

Just raising the questions.  Do I correctly recall (without criticism) PIOMAS has a +\- 750KM3 uncertainty? You make a reasonable counter question about TOPAZ I don't have a good answer for.

I'm also fascinated to see some of the ice directly, in the Beaufort, via the Healy. I'd be curious to hear your and others take on what they show.  Vergent suggests they imply thickness close to TOPAZ's estimates.  Why, or why not?  Does this raise questions about other assumptions of thickness used to extrapolate volume?

I'll be digging a bit on this m'self. Might want another thread.
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #97 on: August 26, 2013, 08:34:58 PM »
AndrewP - thank you for the concise clarification.
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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #98 on: August 26, 2013, 08:37:52 PM »
It was clear in 2011 that TOPAZ was not doing a good job in modelling sea ice thickness. Back then I compared different thickness models (PIPS, PIOMAS and TOPAZ) in this and that blog post, although I hadn't concluded yet that TOPAZ didn't give good info.

I don't feel that TOPAZ has improved much since then. I'm not a fan of PIPS/ACNFS either. PIOMAS is by far the best thing we have, next to CryoSat measurements.

Quote
So again to summarize these are the three primary reasons that a prediction of SIA in the low 3s +/- 800k, and SIE in the mid 4s +/-800k was possible by early June. I repeated these three reasons often and emphatically.

1. SIV was in a tie with 2010

2. SIA was the highest since 2004.

3. The weather for the remainder of the summer was unlikely to be as hostile as it was in 2012. 2012 was an outlier, even in the new modern climate.

Why the big, bold font? Is this just about you being right? I'm asking people not to provoke you, and as a thanks you go all big and bold on me? Why not add triple exclamation marks after each sentence, while you're at it.  ???

I don't agree that 2012 weather was an outlier in the Arctic's new normal period, but perhaps the start was. This year we've seen how important the start seems to be for the remainder of the melting season.
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AndrewP

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Re: NSIDC 2013 Arctic SIE September minimum: July poll
« Reply #99 on: August 26, 2013, 08:41:54 PM »
It was clear in 2011 that TOPAZ was not doing a good job in modelling sea ice thickness. Back then I compared different thickness models (PIPS, PIOMAS and TOPAZ) in this and that blog post, although I hadn't concluded yet that TOPAZ didn't give good info.

I don't feel that TOPAZ has improved much since then. I'm not a fan of PIPS/ACNFS either. PIOMAS is by far the best thing we have, next to CryoSat measurements.

Quote
So again to summarize these are the three primary reasons that a prediction of SIA in the low 3s +/- 800k, and SIE in the mid 4s +/-800k was possible by early June. I repeated these three reasons often and emphatically.

1. SIV was in a tie with 2010

2. SIA was the highest since 2004.

3. The weather for the remainder of the summer was unlikely to be as hostile as it was in 2012. 2012 was an outlier, even in the new modern climate.

Why the big, bold font? Is this just about you being right? I'm asking people not to provoke you, and as a thanks you go all big and bold on me? Why not add triple exclamation marks after each sentence, while you're at it.  ???

I don't agree that 2012 weather was an outlier in the Arctic's new normal period, but perhaps the start was. This year we've seen how important the start seems to be for the remainder of the melting season.

It was bold because it was a long post, and I felt that was the most important part and did not want people to miss it. A lot of people have been accusing me of not providing reasoning for my predictions, but I have been. So I bolded it.

I agree most of the hostility from 2012 was primarily due to the beginning, although I would describe the remainder as still somewhat more hostile than other recent years. In any case, I don't think a repeat of 2012-weather overall could be justified.