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What will the NSIDC 2017 Arctic SIE September average be?

Between 5.0 and 5.5 million km2
0 (0%)
Between 4.75 and 5.25 million km2
3 (2.8%)
Between 4.5 and 5.0 million km2
10 (9.3%)
Between 4.25 and 4.75 million km2
26 (24.3%)
Between 4.0 and 4.5 million km2
16 (15%)
Between 3.75 and 4.25 million km2
16 (15%)
Between 3.5 and 4.0 million km2
12 (11.2%)
Between 3.25 and 3.75 million km2
9 (8.4%)
Between 3.0 and 3.5 million km2
5 (4.7%)
Between 2.75 and 3.25 million km2
3 (2.8%)
Between 2.5 and 3.0 million km2
3 (2.8%)
Between 2.25 and 2.75 million km2
0 (0%)
Between 2.0 and 2.5 million km2
0 (0%)
Between 1.75 and 2.25 million km2
0 (0%)
Between 1.5 and 2.0 million km2
1 (0.9%)
Between 1.25 and 1.75 million km2
0 (0%)
Between 1.0 and 1.5 million km2
1 (0.9%)
Between 0.75 and 1.25 million km2
0 (0%)
Between 0.5 and 1.0 million km2
2 (1.9%)
Between 0.25 and 0.75 million km2
0 (0%)
Between 0 and 0.5 million km2
0 (0%)

Total Members Voted: 107

Voting closed: August 12, 2017, 07:53:08 AM

Author Topic: NSIDC 2017 Arctic SIE September average: August poll  (Read 2285 times)

Neven

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NSIDC 2017 Arctic SIE September average: August poll
« on: August 01, 2017, 07:53:08 AM »
ATTENTION: There are two polls on the ASIF. This one is for NSIDC sea ice extent monthly minimum or September average (which is also used for the SIPN sea ice outlook), the other is for JAXA sea ice extent daily minimum (provided by ADS, previously by IJIS). Make sure you are aware of the difference before voting. You can discuss various extent/area data sets in this dedicated thread.

-----

This NSIDC extent poll will run for 11 days (until August 12th). Until then you can change your vote. Here are the results for the June poll and July poll. There will be a new poll next month.

Here's how things are currently looking based on data up to July 31st:



These are the September averages for the last 12 years (in millions km2, found here):

    2005: 5.59
    2006: 5.95
    2007: 4.32
    2008: 4.74
    2009: 5.39
    2010: 4.93
    2011: 4.63
    2012: 3.63
    2013: 5.35
    2014: 5.29
    2015: 4.68
    2016: 4.72

You can use the comment thread below to motivate your choice, but discuss various SIE/SIA data sets in this dedicated thread.
« Last Edit: August 02, 2017, 11:43:07 AM by Neven »
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Richard Rathbone

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #1 on: August 01, 2017, 12:30:13 PM »
Up 1 bin, now thinking there's rather more risk of it being a little higher than last year rather than a bit lower, based on the current state of the Slater projection. http://cires1.colorado.edu/~aslater/SEAICE/

gerontocrat

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #2 on: August 01, 2017, 12:52:01 PM »
I need all the help I can get. So I am waiting for the PIOMAS for July, especially Neven's analysis, plus to see if the Arctic weather does turn nasty over the next week or so. Only then will I put my incorrect guess in.

Ned W

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #3 on: August 01, 2017, 01:06:55 PM »
Based on today's JAXA and the past decade's JAXA-daily-vs-NSIDC-monthly comparison, I'd expect 4.64 +- 0.74 (95% CI). 

A difference of only 0.12 would separate 3rd place (just below 2011) from 7th place (just above 2008).  It's quite crowded there in that 4.63 - 4.74 range.  The actual predicted value of 4.64 would mean squeezing into the very small gap between 2011 and 2015, for 4th place.

For now I'll go with 4.25-4.75, but I might revise that depending on how the next 10 days unfold.

Ned W

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #4 on: August 01, 2017, 01:26:09 PM »
Here's the graph showing the relationship between current (Day 213) JAXA extent and the September monthly NSIDC extent:



Interpret it as you will.  The red dot shows the expected value based on the average difference between Day 213 and Sept. monthly.

I note that over one-third of the early responses to the poll are outside the 95% confidence interval for that estimate (all on the low side).  Just sayin'.

Ned W

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #5 on: August 01, 2017, 01:39:33 PM »
OK, here are the a priori probabilities of each bin, based on the 2007-2016 historical record of JAXA Day 213 vs NSIDC Sept mean:

Over 5.75:   <1%
5.50 to 6.00:    1%
5.25 to 5.75:    5%
5.00 to 5.50:   15%
4.75 to 5.25:   33%
4.50 to 5.00:   48%
4.25 to 4.75:   47%
4.00 to 4.50:   31%
3.75 to 4.25:   14%
3.50 to 4.00:    4%
Under 3.75:   <1%

Total is more than 100% because of the overlapping bins. 

Disclaimer: If one believes that this year's "conditions" (thickness? weather?) are radically different from previous years, one might then expect that this model would not be accurate.

Paddy

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #6 on: August 01, 2017, 02:16:43 PM »
4.25 to 4.75 for me.

jdallen

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #7 on: August 01, 2017, 05:17:03 PM »
4.5-5.0

I think the ice will be more dispersed, which follows the poor quality we have seen.

Much still depends on weather.  I am keen to see what the next storms do, as badly placed, the could radically change the outcome.
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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #8 on: August 01, 2017, 07:15:42 PM »
This is a current list of the September NSIDC monthly SIE average were the remainder of the 2017 melting season were to exactly follow the behavior of any of the last 12 seasons (2005-2016):

2016: 4.5M km2
2015: 4.429M km2
2014: 4.845M km2
2013: 4.892M km2
2012: 3.858M km2
2011: 4.56M km2
2010: 4.755M km2
2009: 4.904M km2
2008: 4.02M km2
2007: 4.298M km2
2006: 5.158M km2
2005: 4.988M km2

That's a minimum of 3.858 (2012), a maximum of 5.158 (2006), and a 12-year average of 4.601.

Based on all of that, September 2017 SIE should come in between 4.35 and 4.65. That is, options  #3, #4, or #5. I went with #4 for now.

Daniel B.

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #9 on: August 01, 2017, 07:37:41 PM »
4.25 to 4.75.  6th lowest overall.

RealityCheck

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #10 on: August 01, 2017, 11:20:09 PM »
Extent holds up while volume declines significantly. But we're entering a more volatile phase of life for arctic sea ice IMO. Relatively smaller events (e.g. cyclones) have greater potential to affect the extent figures disproportionately relative to previous years' impacts. If we get one or two reasonably strong storms, extent could well trend lower than other years' data would suggest. But not a new low this year it seems...
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RealityCheck

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #11 on: August 01, 2017, 11:24:12 PM »
So 4.25 to 4.75 I think.
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magnamentis

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #12 on: August 02, 2017, 02:27:33 AM »
3.75 - 4.25, second lowest over all, no change to my earlier votes
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Bruce Steele

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #13 on: August 02, 2017, 03:01:11 AM »
Up one bin 4.00- 4.50

Neven

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #14 on: August 02, 2017, 11:48:12 AM »
I've added the graph based on the latest data.

I'm going to stick with last month's vote, 4.25-4.75, but I might change before the poll expires.

Edit: I actually voted between 4.0-4.5 last month, as I did in June, so I've gone up a bin.
« Last Edit: August 02, 2017, 12:51:44 PM by Neven »
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icefisher

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #15 on: August 03, 2017, 03:57:47 AM »
Missing the major storm that my initial guess included.  Extent 4.665, but volume may reach an all time low with a little help from weaker cyclones on the Pacific side of the CAB.

greatdying2

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #16 on: August 03, 2017, 04:15:35 AM »
3.5 - 4. Up one bin because the extent has been slower to respond to the ice thinness than it might have. I still think we have a good chance at 2nd, or possibly even a new record depending on how bad the weather gets.
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Archimid

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #17 on: August 03, 2017, 05:42:06 AM »

Disclaimer: If one believes that this year's "conditions" (thickness? weather?) are radically different from previous years, one might then expect that this model would not be accurate.

 Maybe not "radically different" but volume is about the same as the lowest value. I guess we are all waiting to see how significant that might be.
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meddoc

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #18 on: August 03, 2017, 07:46:37 AM »
3- 3,5 million km2.
But mostly Rubble.

deconstruct

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #19 on: August 03, 2017, 08:49:16 AM »
3.75 to 4.25

I guess that 2017 will come in second.

The overall weather was just too cold and not favorable for ice melt than in other record years, the condition of the ice is still bad nonetheless. But it still would be a huge deal IMO, if 2017 would come in second (or even third), despite the ice-friendly weather over most of the melting season and the lack of precondition due to more snow on the ice earlier and only little ice-export through Fram strait.

That would just show, how thin the ice is and would make one wonder, how low extent could get, in a strong melting year.

Juan C. García

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #20 on: August 03, 2017, 12:31:33 PM »
I'm voting 4-4.5 million km2.
I still believe that the low volume will make the 2017 daily value to be under 2007, but a freeze on the second half of September and the NSIDC algorithm could make that the NSIDC official monthly average could be above 2007.

I have gone up 2 bins.
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.

EgalSust

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #21 on: August 03, 2017, 02:35:16 PM »
4.5-5 - same as July. Might change it before the deadline though if there is remarkable melting action...

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #22 on: August 03, 2017, 03:42:57 PM »
the numbers of the last couple of days make me doubt again if I shouldn't choose for a new record.

I still have the gut-feeling it will be worse then most of us, including myself, expect, but I can't put my finger on it...

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #23 on: August 06, 2017, 04:03:13 PM »
Voting 4.25 to 4.75 mill. Km2 despite the hiccup of today

gerontocrat

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #24 on: August 07, 2017, 01:05:36 PM »
Also going for 4.25 to 4.75 million km2, based on a daily Jaxa extent minimum of 4.1 million km2 + 0.4 million km2 as the average difference with the NSIDC month average.

RikW

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #25 on: August 09, 2017, 08:48:20 AM »
I guess the daily minimum will drop below 4.00, and it will hover most of september around that point, so the average will be slightly above 4.00.

For now i'm going for 3.75 - 4.25, but i'm doubting to change to 4.00 - 4.50. Luckily I still have 3 days to make the final decision :)

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #26 on: August 09, 2017, 02:09:13 PM »
To attempt to capture the fact that the atmosphere is cold but the ice is thin I voted low on the daily poll but I voted high on the monthly poll, 4.25-4.75. I think that after a near record daily low, the arctic will undergo rapid growth for at least a few weeks, maybe months.
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Juan C. García

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #27 on: August 10, 2017, 08:11:27 PM »
Less than 2 days, to make your vote or change it!  :)
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.

epiphyte

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #28 on: August 11, 2017, 09:08:45 AM »
IIRC I didn't vote last month - but then I would have been lower than where I am now, which is 3.5-4.0. I think that the minimum might well come in early, and bump along the bottom for a while due to ongoing melt in some regions long after that...


seaice.de

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #29 on: August 11, 2017, 12:44:25 PM »
My sea ice outlook contribution: 4.2 +- 0.4

Jim Hunt

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #30 on: August 11, 2017, 12:52:36 PM »
My sea ice outlook contribution: 4.2 +- 0.4

No new record then Lars?!
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seaice.de

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #31 on: August 11, 2017, 01:18:08 PM »
Well, not entirely ruled out. The lower bound of the error bar scratches 2012 which leaves some possibility. But just from the statistics I would say that a new record is not likely.

My sea ice outlook contribution: 4.2 +- 0.4

No new record then Lars?!

Neven

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #32 on: August 11, 2017, 05:56:28 PM »
Less than 2 days, to make your vote or change it!  :)

I'm sticking with 4.25-4.75.
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Pavel

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #33 on: August 11, 2017, 06:19:26 PM »
I change my previous bets rising it by 0.75 mln. Now 3.75-4.25 lowest daily and 4.25-4.75 September average. Likely another mild winter or warm summer needed to break records

magnamentis

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #34 on: August 11, 2017, 09:47:13 PM »
be patient, the main difference this year is thickness and logically it will show on the last mile, means during the last few weeks of the melting season. it's already hinting and if the weather conditions won't see to a very early minimum and a calm reminder of the season i still think we're getting close ( opted for second lowest from the beginning and stick to it )

BTW, talking about being close at the end of the season, IMO we are permanently close to the lowest at almost any time this year or below earlier. i opt for a sudden death over wide areas for the reason mentioned above.
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iceman

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #35 on: August 11, 2017, 10:25:20 PM »
I'm guessing September's graph will be more V-shaped than usual, and therefore the resulting rank for the month's average could be as low as 6th even if the daily min (other poll) is higher.  So going with 4.25 to 4.75.

Peter Ellis

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Re: NSIDC 2017 Arctic SIE September average: August poll
« Reply #36 on: August 12, 2017, 07:21:21 PM »
I'm guessing September's graph will be more V-shaped than usual, and therefore the resulting rank for the month's average could be as low as 6th even if the daily min (other poll) is higher.  So going with 4.25 to 4.75.
I was all prepared to argue this, then I realised that your 'higher' actually meant lower amounts of ice, and vice versa.