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What position will the arctic sea ice jaxa extent minimum in 2018 be in the annual rankings so far?

1 or 2 (i.e. lowest or second lowest yet)
47 (63.5%)
2 or 3
12 (16.2%)
3 or 4
7 (9.5%)
4 or 5
5 (6.8%)
5 or 6
1 (1.4%)
6 or 7
1 (1.4%)
7 or 8
0 (0%)
8 or 9
1 (1.4%)
9 or 10
0 (0%)
10 or 11
0 (0%)
11 or 12
0 (0%)
>12
0 (0%)

Total Members Voted: 72

Voting closed: April 10, 2018, 09:46:16 AM

Author Topic: Arctic sea ice minimum early prediction  (Read 14915 times)

Paddy

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Arctic sea ice minimum early prediction
« on: March 27, 2018, 09:46:16 AM »
A poll for very early guesses. You have two weeks to reply, but can change your guess if you want to.

I'm aiming to add a list of the jaxa minima from previous years here later, but if someone else wants to do that first, please feel free.

Pmt111500

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Re: Arctic sea ice minimum early prediction
« Reply #1 on: March 27, 2018, 11:51:59 AM »
This really is too early, so put in the 1-2 vote, as there's no option of zero. Can't though imagine how a zero-ice or virtually ice free would be experienced just this summer. Maybe Atlantic and Pacific inputs meet somewhere near continental margin of East Siberian and the resulting vortex, that could be named Pruitt, might move under the thickest ice left destroying it all. As I said, it's too early but in some other sense also too late. Sorry, I try to cut back the doom and the politics, but it's not working too well.
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oren

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Re: Arctic sea ice minimum early prediction
« Reply #2 on: March 27, 2018, 11:56:21 AM »
It's too early.  Not even sure why I voted...

RikW

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Re: Arctic sea ice minimum early prediction
« Reply #3 on: March 27, 2018, 02:43:38 PM »
This really is too early, so put in the 1-2 vote, as there's no option of zero. Can't though imagine how a zero-ice or virtually ice free would be experienced just this summer. Maybe Atlantic and Pacific inputs meet somewhere near continental margin of East Siberian and the resulting vortex, that could be named Pruitt, might move under the thickest ice left destroying it all. As I said, it's too early but in some other sense also too late. Sorry, I try to cut back the doom and the politics, but it's not working too well.

Even having zero ice means it's first position ;)

I voted 1-2 since the multi-year trend is down, so logic dictates we will have record low years regularly

jdallen

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Re: Arctic sea ice minimum early prediction
« Reply #4 on: March 27, 2018, 08:38:28 PM »
What Rikw said.  I'm not comfortable staking myself to exact numbers, but can make a qualitative guess.

My choice is founded on winter heat combined with current weakness in the Chukchi, the incredible vanishing Bering, the Svalbard gap, and general poor quality of ice in the Barentz and Kara.

I think early retreat in the Chukchi will lead to a general collapse of the Beaufort and ESS which will turn into killing grounds for ice transported there from the central basin.

The Laptev will catch up as Siberian late spring heat manifests, which combined with retreat in the Kara and Barentsz will turn into a serious assault on the basin proper in late July and August.
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Dharma Rupa

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Re: Arctic sea ice minimum early prediction
« Reply #5 on: March 27, 2018, 10:39:33 PM »
My choice is founded on winter heat combined with current weakness in the Chukchi, the incredible vanishing Bering, the Svalbard gap, and general poor quality of ice in the Barentz and Kara.

Two years of really low Freezing Degree Days, record heat in the North-west Pacific, and continued inflow of warm Atlantic waters...

What could go wrong?

Iceismylife

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Re: Arctic sea ice minimum early prediction
« Reply #6 on: March 28, 2018, 03:39:55 AM »
In spite of last years embarrassment over not melting very much I'm voting for a lot of melt.

Juan C. García

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Re: Arctic sea ice minimum early prediction
« Reply #7 on: March 28, 2018, 07:32:26 AM »
2 or 3

The second lowest is bad enough for me.
Hope that 2018 will not be the lowest.  ;)
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.

Pmt111500

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Re: Arctic sea ice minimum early prediction
« Reply #8 on: March 28, 2018, 09:37:06 AM »
In spite of last years embarrassment over not melting very much I'm voting for a lot of melt.
Hear hear. Still I've got no clue whether to wait for a really low antarctic winter area or this.
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jdallen

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Re: Arctic sea ice minimum early prediction
« Reply #9 on: March 28, 2018, 10:23:44 AM »
26 (63.4%)

Interesting numbers. When the silent majority speaks, it's deafening.
You are expecting this year to come in at 26th place?

What silent majority are you speaking of?
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Avalonian

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Re: Arctic sea ice minimum early prediction
« Reply #10 on: March 28, 2018, 11:02:50 AM »
63.4% of the first 26 votes may have gone with the lowest bin, indeed... but I've got to say that some of that majority really aren't very silent, and besides, expectations ain't real chickens. Yet.  ;)

I went for the 2nd bin as most being most likely, because of the mid-summer slowing that seems to be a regular pattern now (at least until the next El Nino). But that expectation ain't a chicken either, and I will not be too surprised if we do see a new record after all. And if it does go low, then I won't be surprised at even a really eye-popping new record.  :o

But we shall see. It's interesting to get the gut feeling of interested people, no matter how impossible the predicting may be at this stage.

oren

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Re: Arctic sea ice minimum early prediction
« Reply #11 on: March 28, 2018, 11:31:24 AM »
In all fairness, the probabilities are all over the place, and the guesses are quasi-random (at least mine is). It would be interesting to have a poll asking what people think is the probability for some kind of outcome (<X km2, >X km2, new record, whatever). I think every year now has a ~20%-25% probability of a new record, and a ~10% probability of a BOE (<1M).

Dharma Rupa

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Re: Arctic sea ice minimum early prediction
« Reply #12 on: March 28, 2018, 01:38:43 PM »
In all fairness, the probabilities are all over the place, and the guesses are quasi-random (at least mine is). It would be interesting to have a poll asking what people think is the probability for some kind of outcome (<X km2, >X km2, new record, whatever). I think every year now has a ~20%-25% probability of a new record, and a ~10% probability of a BOE (<1M).

I'd go a bit higher, but in the same ballpark -- about 30% and 15% respectively.

Paddy

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Re: Arctic sea ice minimum early prediction
« Reply #13 on: March 28, 2018, 03:56:26 PM »
Thise promised JAXA figures from previous years (laxily copy-pasted from a previous poll):


1980's Avg:   7.23
1990's Avg:   6.55
2000's Avg:   5.48
2000:   6.04 
2001:   6.55 
2002:   5.53 
2003:   5.93
2004:   5.68
2005:   5.18
2006:   5.63
2007:   4.07 (3rd)
2008:   4.50
2009:   5.05
2010:   4.62
2011:   4.27 (5th)
2012:   3.18 (1st)
2013:   4.81
2014:   4.88
2015:   4.26 (4th)
2016:   4.02 (2nd)
2017:   4.87

On the basis of these, I'm switching my vote from 2nd or 3rd to 1st or 2nd, since the window between the current 2nd and 3rd positions is so narrow that it seems even less likely than a new record to me. One of many problens with the design of this rather silly poll.

Juan C. García

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Re: Arctic sea ice minimum early prediction
« Reply #14 on: March 28, 2018, 04:13:35 PM »
On the basis of these, I'm switching my vote from 2nd or 3rd to 1st or 2nd, since the window between the current 2nd and 3rd positions is so narrow that it seems even less likely than a new record to me. One of many problens with the design of this rather silly poll.

I agree that been between 2016 (2nd place, 4.02M km2) and 2007 (3th place, 4.07M Km2) is so narrow that it is more possible to break the record. But one problem that we have on this Forum, is that we show that we are so pessimistic, that when the melting season ends, we look far away of what really happen.

The true is that being between 2012 and 2016, is bad enough. Even if 2018 ends up in 6th place, a little above 2011 (5th place, 4.27M km2), it means that the Arctic continues in terrible situation.
¿So why always betting for the worst-case scenario?
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.

Cid_Yama

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Re: Arctic sea ice minimum early prediction
« Reply #15 on: March 28, 2018, 04:29:10 PM »
Because that is our opinion.  It's not pessimistic, it's realistic.

Better to ask why so many tenaciously refuse to see the elephant in the room.

 
"For my part, whatever anguish of spirit it may cost, I am willing to know the whole truth; to know the worst and provide for it." - Patrick Henry

Juan C. García

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Re: Arctic sea ice minimum early prediction
« Reply #16 on: March 28, 2018, 05:58:18 PM »
I'm aiming to add a list of the jaxa minima from previous years here later, but if someone else wants to do that first, please feel free.

I think I had it right.
Add 2017: 4.47 [Not 4.87]

This JAXA Arctic Sea Ice Extent (previously released by IJIS, and now by ADS and NIPR) poll will run for 11 days. Until then you can change your vote. There will be a new poll next month.

These are the daily September minimums (in millions km2):

1980's Avg:   7.23
1990's Avg:   6.55
2000's Avg:   5.48
2000:   6.04
2001:   6.55
2002:   5.53
2003:   5.93
2004:   5.68
2005:   5.18
2006:   5.63
2007:   4.07
2008:   4.50
2009:   5.05
2010:   4.62
2011:   4.27
2012:   3.18
2013:   4.81
2014:   4.88
2015:   4.26
2016:   4.02
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.

Pmt111500

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Re: Arctic sea ice minimum early prediction
« Reply #17 on: March 28, 2018, 06:35:03 PM »
2010-16  4.29

and soneone could make a graph of averages over five years of minimums. Hide the El Nino effects away if there indeed are some.
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jdallen

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Re: Arctic sea ice minimum early prediction
« Reply #18 on: March 28, 2018, 06:47:53 PM »
26 (63.4%)

Interesting numbers. When the silent majority speaks, it's deafening.
You are expecting this year to come in at 26th place?

What silent majority are you speaking of?

Um. Ah. The poll numbers at the top of the page.  ???
Ah, very good. Didn't get the reference. Do carry on. :)
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Yuha

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Re: Arctic sea ice minimum early prediction
« Reply #19 on: March 28, 2018, 07:33:45 PM »
My rough estimate of probabilities:
- 1/3 for 1 or 2 (most likely 2)
- 1/3 for 3 or 4 (most likely 4)
- 1/3 for 5 or higher (most likely 6)
My vote goes to 3 or 4 for now.

uniquorn

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Re: Arctic sea ice minimum early prediction
« Reply #20 on: March 28, 2018, 08:41:08 PM »
My choice is founded on winter heat combined with current weakness in the Chukchi, the incredible vanishing Bering, the Svalbard gap, and general poor quality of ice in the Barentz and Kara.
Two years of really low Freezing Degree Days, record heat in the North-west Pacific, and continued inflow of warm Atlantic waters...
All the above and probable repeat of open water north of Greenland.

Peter Ellis

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Re: Arctic sea ice minimum early prediction
« Reply #21 on: March 29, 2018, 01:50:02 PM »
Nice illustration here of the general mathematical literacy level of this forum.

There is virtually no chance that this year can come in 3rd. 2007 and 2016 are so close it's almost impossible to end up with a value in between them.  Ergo, since 3rd place can't happen, you should either vote for the (1-2) bracket) or the (4-5) bracket to maximise your chances of success.

And yet 22.8% of the voters have chosen to pick brackets that demonstrably lower their chance of being correct.

Richard Rathbone

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Re: Arctic sea ice minimum early prediction
« Reply #22 on: March 29, 2018, 02:13:27 PM »
Nice illustration here of the general mathematical literacy level of this forum.

There is virtually no chance that this year can come in 3rd. 2007 and 2016 are so close it's almost impossible to end up with a value in between them.  Ergo, since 3rd place can't happen, you should either vote for the (1-2) bracket) or the (4-5) bracket to maximise your chances of success.

And yet 22.8% of the voters have chosen to pick brackets that demonstrably lower their chance of being correct.

The window for 3rd isn't that small, there are smaller windows for other places, including 5th ...

Archimid

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Re: Arctic sea ice minimum early prediction
« Reply #23 on: March 29, 2018, 02:27:33 PM »
Nice illustration here of the general mathematical literacy level of this forum.
11 forum members voted for that bracket, out of more than a thousand, yet you derive the "the general mathematical literacy level of this forum." based on those 11 and a poor assumption. LOL

I voted for 1 or 2.
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Avalonian

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Re: Arctic sea ice minimum early prediction
« Reply #24 on: March 29, 2018, 03:17:00 PM »
Peter, you might want to consider that the size of the bins may be outweighed by a probability skew towards the part of the distribution one believes it's likely to end up in. The probability distribution is not even, and people's responses illustrate their perceived view of the curve. I still suspect it's much more likely to be around the 2007 level, rather than 2012, and therefore there's a higher chance of being in the narrow third place than in the much wider, but low-probability first place.

Pmt111500

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Re: Arctic sea ice minimum early prediction
« Reply #25 on: March 29, 2018, 03:31:44 PM »
Note also that voting for 1-2 is entirely sensible as it is the second largest bin.
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2phil4u

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Re: Arctic sea ice minimum early prediction
« Reply #26 on: March 29, 2018, 10:02:59 PM »
Im a little confused about the numbers.
Not sure what dates and values are exactly taken, because normally
1.2012
2.2007

My guess, 2017 was a catastrophic begin, this year isnt this much better, the pacific side is just ugly.
But we have a solar minimum, we have good snow cover, summer tended to be cool lately.
So my guess is place 8, not saying this is the most likely outcome, but i want to seperate me from some people, dont know what in their mind, but i saw predictions from experts saying every year 0 or so, what is in thier head, are they fanatic in their not working models, or what is the reason ?
And of course, if we would put money for the bet, im the only with this outcome, so i dont need 25% or 20%.

But who knows the propabilitys exactly ?
Ice thickness is not this bad in some areas, im not sure how damaging a weaker chucki is.

« Last Edit: March 29, 2018, 10:09:42 PM by 2phil4u »

2phil4u

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Re: Arctic sea ice minimum early prediction
« Reply #27 on: March 29, 2018, 10:17:34 PM »
Didnt watched for the numbers exactly.
It is only numbered to place 4.
So there are years with very similar ice, and then if i recogize correcly 4.5,4.61,4.81.4.82
But it is not important, so now im over 4.5 and below 4.81 but one tipped 6,7 so i can only win if its between 4.61 and 4.81 and im with another with 4.5 to 4.6.
If it would be a money tip, i think im fine.
But of course if it would be a money bet, nobody would bet at first !
Maybe the 4.61 would have been better, we were only 8 or 9 place last year, so this is not unlikely.
« Last Edit: March 29, 2018, 10:47:51 PM by 2phil4u »

Archimid

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Re: Arctic sea ice minimum early prediction
« Reply #28 on: March 29, 2018, 11:15:55 PM »
Quote
But of course if it would be a money bet, nobody would bet at first!

I bet some people would bet on first regardless. After all, without someone taking the bad bets there wouldn't be any betting at all.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Pmt111500

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Re: Arctic sea ice minimum early prediction
« Reply #29 on: March 30, 2018, 08:02:44 AM »
Quote
But of course if it would be a money bet, nobody would bet at first!

I bet some people would bet on first regardless. After all, without someone taking the bad bets there wouldn't be any betting at all.
Provided I get the bank account details, social security info and the credit card number with the security codes and other personal info I might be tempted. Keys to the apartment and car should be also provided as a guarantee so in case of the eventual loss assets may be transferred forcefully. Beachfront properties not accepted. ;-)
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Daniel B.

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Re: Arctic sea ice minimum early prediction
« Reply #30 on: March 30, 2018, 02:18:54 PM »
On the basis of these, I'm switching my vote from 2nd or 3rd to 1st or 2nd, since the window between the current 2nd and 3rd positions is so narrow that it seems even less likely than a new record to me. One of many problens with the design of this rather silly poll.

I agree that been between 2016 (2nd place, 4.02M km2) and 2007 (3th place, 4.07M Km2) is so narrow that it is more possible to break the record. But one problem that we have on this Forum, is that we show that we are so pessimistic, that when the melting season ends, we look far away of what really happen.

The true is that being between 2012 and 2016, is bad enough. Even if 2018 ends up in 6th place, a little above 2011 (5th place, 4.27M km2), it means that the Arctic continues in terrible situation.
¿So why always betting for the worst-case scenario?

I tried to remove my feelings about the ice, and do a pseudo-scientific determination (totally unproven).  Looking at the date of maximum sea ice, the later the date, the higher the minimum (this worked for all years, except for 2007 and 2012).  Based on the date of maximum, the minimum would fall in 7th place, so I placed my vote there.  However, since two of the years with the latest maxima showed the lowest minima, it was equally logical that it could fall in that range, so I was divided between 1/2 and 6/7.  Since most chose the pessimistic 1/2, I went for the less popular 6/7; betting against the crowd.

Archimid

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Re: Arctic sea ice minimum early prediction
« Reply #31 on: March 30, 2018, 02:49:01 PM »
Yep. Any bets involving and ice free Arctic shouldn't be for money, as it may become worthless. Generators, batteries, bullets, food and water are the only acceptable payout.
I am an energy reservoir seemingly intent on lowering entropy for self preservation.

Alexander555

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Re: Arctic sea ice minimum early prediction
« Reply #32 on: March 30, 2018, 02:54:59 PM »
I voted for "1 or 2" . Chukchi looks bad compared to last year, the same for the Beaufort Sea. And i see few places that look outspoken better. So under the same conditions it should be lower.

2phil4u

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Re: Arctic sea ice minimum early prediction
« Reply #33 on: March 31, 2018, 01:58:12 PM »
<snip, wildly off-topic; N.>
« Last Edit: April 02, 2018, 10:39:41 AM by Neven »

Steven

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Re: Arctic sea ice minimum early prediction
« Reply #34 on: April 02, 2018, 12:44:28 PM »
For what it's worth, using the long term linear trend over 1979-2017, a normal distribution with a mean of 4.1 million km2 and a standard deviation of 0.55 million km2 would give the following probabilities:

1st lowest:       4.7%
2nd:              39.5%
3rd:                 3.6%
4th:               13.6%
5th:                 0.7%
6th:               12.8%
7th:                 1.7%
8th:                 6.1%
9th:                 7.4%
10th or more:   9.8%

pauldry600

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Re: Arctic sea ice minimum early prediction
« Reply #35 on: May 13, 2018, 02:24:29 PM »
8th will be my vote

gerontocrat

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Re: Arctic sea ice minimum early prediction
« Reply #36 on: May 13, 2018, 06:52:27 PM »
For what it's worth, using the long term linear trend over 1979-2017, a normal distribution with a mean of 4.1 million km2 and a standard deviation of 0.55 million km2 would give the following probabilities:

1st lowest:       4.7%
2nd:              39.5%
3rd:                 3.6%
4th:               13.6%
5th:                 0.7%
6th:               12.8%
7th:                 1.7%
8th:                 6.1%
9th:                 7.4%
10th or more:   9.8%
I really hope you give the algorithm another spin in about 10 days time just before the end poll date of May 27. Although my bruised ego is loath to make predictions, the GFS and other forecasts seem to say there could well be some significant warmth moving North on both the Atlantic and Pacific sides in the next 10 days.

Just maybe your normal distribution will shift to the left somewhat?

ps: At the moment I am stuck between 2nd and 4th as the range of minima is so small.
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Daniel B.

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Re: Arctic sea ice minimum early prediction
« Reply #37 on: May 13, 2018, 08:01:16 PM »
For what it's worth, using the long term linear trend over 1979-2017, a normal distribution with a mean of 4.1 million km2 and a standard deviation of 0.55 million km2 would give the following probabilities:

1st lowest:       4.7%
2nd:              39.5%
3rd:                 3.6%
4th:               13.6%
5th:                 0.7%
6th:               12.8%
7th:                 1.7%
8th:                 6.1%
9th:                 7.4%
10th or more:   9.8%
I really hope you give the algorithm another spin in about 10 days time just before the end poll date of May 27. Although my bruised ego is loath to make predictions, the GFS and other forecasts seem to say there could well be some significant warmth moving North on both the Atlantic and Pacific sides in the next 10 days.

Just maybe your normal distribution will shift to the left somewhat?

ps: At the moment I am stuck between 2nd and 4th as the range of minima is so small.

Both are good options, with high probabilities.  I went with the next highest slot, 6th, based primarily on a cooler Atlantic.

Wherestheice

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Re: Arctic sea ice minimum early prediction
« Reply #38 on: May 13, 2018, 09:25:26 PM »
I think were headed for a new record low. By no means anything higher than 2nd place
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jdallen

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Re: Arctic sea ice minimum early prediction
« Reply #39 on: May 13, 2018, 09:40:21 PM »
I think were headed for a new record low. By no means anything higher than 2nd place
It is more probable than not, but as I've found previously when making such predictions myself, June and July weather can play merry hob on your expectations.
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Alexander555

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Re: Arctic sea ice minimum early prediction
« Reply #40 on: May 13, 2018, 09:58:25 PM »
And what is the main reason that it misses your expectations in June and July, if there is a reason.

jai mitchell

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Re: Arctic sea ice minimum early prediction
« Reply #41 on: May 13, 2018, 10:26:22 PM »
And what is the main reason that it misses your expectations in June and July, if there is a reason.

The primary indicator (that we know so far) that correlates to record minimum sea ice in September is the level of melt pond formation in June (and first half of July) - though I would include second half of May in this.  As you can see from the DMI temperature record, the last five years have had lower temperatures at the early onset of the melt season.

http://ocean.dmi.dk/arctic/meant80n.uk.php

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Re: Arctic sea ice minimum early prediction
« Reply #42 on: May 13, 2018, 10:42:53 PM »
I think were headed for a new record low. By no means anything higher than 2nd place

i agree just be careful, a bit less absolute has proven to be a good advice as i and many learned the hard way LOL.

things can change quickly but again, what you said except that i's have said nothing above 3rd because it's really tight down there when we leave 2012 out ans an outlier for now.

cheers

icefisher

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Re: Arctic sea ice minimum early prediction
« Reply #43 on: May 13, 2018, 11:51:41 PM »
I'm guessing 4.17.  Another cold, cloudy summer?

Dharma Rupa

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Re: Arctic sea ice minimum early prediction
« Reply #44 on: May 13, 2018, 11:54:47 PM »
I think were headed for a new record low. By no means anything higher than 2nd place

i agree just be careful, a bit less absolute has proven to be a good advice as i and many learned the hard way LOL.

things can change quickly but again, what you said except that i's have said nothing above 3rd because it's really tight down there when we leave 2012 out ans an outlier for now.

cheers

Sure, but one year we are going to be right.  The big bet is over whether the ice is going to someday suddenly fall to about zero, or if it is going to trail off and lose ice more slowly as there is less of it.

I am in the Sudden End group....and no, I haven't a clue when.  That is why I don't bother actually voting on these crap shoots -- all I know is that the end will come down hard and sudden.

Alexander555

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Re: Arctic sea ice minimum early prediction
« Reply #45 on: May 13, 2018, 11:55:18 PM »
I think it's going to be a long hot summer.

jdallen

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Re: Arctic sea ice minimum early prediction
« Reply #46 on: May 14, 2018, 04:51:50 AM »
And what is the main reason that it misses your expectations in June and July, if there is a reason.
The weather momentum shifts to conditions that are highly conducive to preserving ice.

In 2013 this was almost epic.  Sometime in late May the weather stalled and in spite of the Arctic ice looking like a sieve, the ice-preserving feedbacks (primarily clouds of various kinds, stagnant circulation and other things that increase albedo) kept us against expectations from blowing past 2012.
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Gray-Wolf

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Re: Arctic sea ice minimum early prediction
« Reply #47 on: May 14, 2018, 12:26:31 PM »
I fear that we are headed for a repeat of the 'general' conditions we saw evolve over the basin over last low solar.
 
If there are two distinct 'average weather' that our solar cycle is at least able to augment across the Basin ( cool/cloudy for high solar and sunny/warm for low solar) then this low solar will see a similar glut of HP dominance over the basin into the the high insolation period?

I'm not saying that our past decade of open waters has had no impact on the weather across the basin but if the same process that delivers North Atlantic blocking over winter over low solar drifts north with the seasons then we have 3 or 4 years with the potential for problems for the ice?

Lets also not forget also that the return period for the perfect melt storm was 10 to 20 years so another concern maybe ( unless the return period is also linked to the low end of the solar cycle?)
We have also seen other changes over the past decade which aids melt without the need for sunny highs?

The papers looking at the changes in ocean water entering the basin, from the Pacific/Atlantic Oceans, mean an increased melt potential from the extra heat getting into the basin. With Bering already ice free any solar is now going into warming that water prior to it flowing into the basin. With that influx 70% bigger than a decade ago that is a lot of melt potential!

The warmth at the Barentsz entrance is now also making greater inroads into the basin as storms during ice free periods mixes out the old basin stratification and allows the heat to stay at the surface as it pushes north.

I worry that this will be the first of a run of 'melt friendly' summers over the basin (like we saw over last low solar) and that todays ice does not stand a chance of surviving such?
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Steven

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Re: Arctic sea ice minimum early prediction
« Reply #48 on: May 14, 2018, 07:51:39 PM »
For what it's worth, using the long term linear trend over 1979-2017, a normal distribution with a mean of 4.1 million km2 and a standard deviation of 0.55 million km2 would give the following probabilities:

1st lowest:       4.7%
2nd:              39.5%
3rd:                 3.6%
4th:               13.6%
5th:                 0.7%
6th:               12.8%
7th:                 1.7%
8th:                 6.1%
9th:                 7.4%
10th or more:   9.8%
I really hope you give the algorithm another spin in about 10 days time just before the end poll date of May 27. Although my bruised ego is loath to make predictions, the GFS and other forecasts seem to say there could well be some significant warmth moving North on both the Atlantic and Pacific sides in the next 10 days.

Just maybe your normal distribution will shift to the left somewhat?

The calculation used only the September sea ice extent minima of previous years.  So it doesn't depend on current extent or weather conditions.

An alternative is to use a quadratic (rather than linear) long term trend.  Then the center of the normal distribution would shift leftward to 3.66M km2 rather than 4.1M km2, and the probabilities would become:

1st lowest:     18.8%
2nd:               55.2%
3rd:                  2.9%
4th:                  9.1%
5th:                  0.4%
6th:                  6.4%
7th:                  0.7%
8th:                  2.3%
9th:                  2.3%
10th or more:    1.9%

Caution: the quadratic trend method performed poorly in the last 5 years: it ended up too low in each of those 5 years.

« Last Edit: May 14, 2018, 08:08:48 PM by Steven »

gerontocrat

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Re: Arctic sea ice minimum early prediction
« Reply #49 on: May 14, 2018, 09:32:54 PM »

Caution: the quadratic trend method performed poorly in the last 5 years: it ended up too low in each of those 5 years.

Thanks, Steven.

I did not realise you looked at the September minima only.

I am not surprised the quadratic looks dodgy - 18% probability for a record low? I think the only year in the 39 year record with melt large enough to achieve that result was 2012. The 4.1 million fits well with my tables that use remaining melt from previous years. Hence my thought that a strong melt in the next 10 days or so would change your analysis.
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