NSIDC 2017 Arctic SIE September average: July poll

[Neven]

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.

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

Here's how things are currently looking based on data up to June 30th:



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.

[Lord M Vader]

I was first to vote! Voted for 4,5-5,0 Mn km².

[magnamentis]

my vote: Between 3.5 and 4.0 million km2

[Tor Bejnar]

I'm the last to vote (so far  )  All 6 votes are in different bins (mine lowest). [Edit: I'm not lowest anymore, and several bins have multiple votes.]

[oren]

I'm the first to join a bin already voted for. 

[Neven]

I have voted between 4.0 and 4.5 million km2, like I did last month. I might change it, depending on what happens.

[echoughton]

I'm with Lord V...4.5-5 Similar to last year, but I believe the increased snow will help it come in just under 5

[Jim Pettit]

I have voted between 4.0 and 4.5 million km2, like I did last month. I might change it, depending on what happens.

Same here. If 2017 were to follow the average trajectory over the past ten years from today forward, the average this September would be 4.28M (IJIS) or 4.24M (NSIDC). I looked at that, then dropped one bin further just because 2017 hasn't yet had its expected cliff-diving moment.

[Paddy]

Going to wait for the Piomas update before I pick, but I expect I'll be adjusting my vote upwards.

[Juan C. García]

Between 3.5 and 4.0 million km².
Kind of even with 2012.

[Neven]

This month's JAXA SIE daily minimum poll has been posted by Juan as well.

[Richard Rathbone]

Sticking at 4.25-4.75

Nothing that happened in June made me stop thinking 2017 will be all that different from 2016 come September.

[epiphyte]

I'm guessing 3.25-3.75  - Tempted to go higher though - mainly because I think that in Sep there might be greater than usual overlap between continuing melt in some areas and refreeze in others.

[gerontocrat]

For those who look at JAXA data a lot, just to note that over the last 10 years the NSIDC Sept average extent has been greater than the JAXA daily minimum extent by an average of 0.40 million km2.

[icefisher]

Extent 4.0 - 4.1.  Volume lowest ever.  Nothing but slush and ice cubes as far as the eye can see.

[Thomas Barlow]

Based on Oren's Arctic Ocean volume graph, record low volume, which could reach a tipping point (collapse), and the crumbling nature of the ice, I have changed my view now, and opted to go for record low this September.
Between 3 and 3.5
Oren's Arctic Ocean volume graph:
---> https://forum.arctic-sea-ice.net/index.php/topic,1834.msg118389.html#msg118389

[cesium62]

Sticking at 4.25-4.75

Nothing that happened in June made me stop thinking 2017 will be all that different from 2016 come September.

Did anything happen in June of 2012 that made you think 2012 would be different than 2016 come September?

Same here. If 2017 were to follow the average trajectory over the past ten years from today forward, the average this September would be 4.28M (IJIS) or 4.24M (NSIDC). I looked at that, then dropped one bin further just because 2017 hasn't yet had its expected cliff-diving moment.

With steadily increasing temperatures, we would expect 2017 to be below the average trajectory of the past 10 years.

The Slater Probabilistic Sea Ice Extent Graph shows a relatively sharp bounce in the predicted mid-August extent, which suggests to me that conditions this year are sufficiently abnormal that tools which worked well in the past are having a hard time with this year.

My takeaway from 2012 is that the weather is rather important.  The ice is looking crappier than usual, so typical weather should put us somewhat below 2007, 2011, 2015, and 2016.  But if a big storm blows through in August, it will easily disperse the ice to the South.  The big storm is over-due.  3.5 +/- 0.25.

But...

[be cause]

I had been following area for years on CT so I have little experience beyond last year even caring what the extent measurements were . That they could be a couple of million higher than area left me bemused .. My area minimum prediction would be around 1 million Km2 so I guess my extent prediction by this measure should be around 3-3.5m .
 What ever the weather , I feel this will continue to be an interesting melt season . I still feel that the past winter will play a major role in the end of season analysis . At this stage of the season I am observing .. and absorbing some .. of the great posts and discussions on this forum . Thanks Neven .. for bringing us together in the Now of weather !

[Reallybigbunny]

Just waiting for a big fat high pressure system to come sit over the arctic for a week or so... 3 - 3.5 

[jdallen]

3.75-4.25

[Richard Rathbone]

Sticking at 4.25-4.75

Nothing that happened in June made me stop thinking 2017 will be all that different from 2016 come September.

Did anything happen in June of 2012 that made you think 2012 would be different than 2016 come September?

Much greater momentum in 2012. The momentum of June 2012 was huge.

[greatdying2]

3.25 to 3.75

Up from 3 to 3.5 last month only because I discovered that this vote is not for the minimum, but rather for the September average. Lots of thin ice. The next few weeks will be interesting.

[meddoc]

Will first analyze the dynamics unfolding in the next 10 days 

[DavidR]

I've moved to  3.75-4.25 for the average.  I  think we will see a record for the daily minimum but like last year it  could be a rapid late plunge, with  lots of well spread ice, rather than a long  leisurely  time at the bottom.

[Paddy]

I may yet change my mind with the next piomas update, but for now I'm going 4.25 to 4.75. This embraces the 2nd through 6th lowest years, which seems fairly likely territory without a major melting event.

[Thomas Barlow]

Based on this I have revised upward my guesstimate to 3.5-4.0
---> https://forum.arctic-sea-ice.net/index.php/topic,1834.msg119231.html#msg119231
I still think the icepack is pretty trashy and vulnerable, so still estimating low.

[Sterks]

Hello. I too am in the ample group that believes that this year's melting season may end somewhere above 2012 and below 2007. Up from last poll, to 3.75 - 4.25 million

[Paddy]

Going down a bin to 4.0 - 4.5

[SteveMDFP]

Between 3.25 and 3.75 million km2
What Cesium62 said

[Steven]

Some updated forecasts for the September 2017 NSIDC sea ice extent:

(1) Alek Petty's forecast is  4.5 +/- 0.3 M km2,  which is somewhat lower than the forecast he made last month.  link.

(2) Lars Kaleschke's forecast is  4.15 +/- 0.45 M km2, slightly higher than his forecast last month.  link.

(3) Rob Dekker's forecast is 5.41 +/- 0.34 M km2, basically the same as his forecast last month.  link.

(4) David Schroeder et al.'s forecast is 5.1 +/- 0.44 M km2, basically the same as last month. link.

(5) The method I used in last month's ASIF poll would give 4.4 +/- 0.4 M km2 using late-June data.  That is slightly higher than last month.

[gerontocrat]

I went for 4.25 to 4.75 million km2.

My reasoning(?) was:-

My Jaxa data analysis of SIE daily minimum has been stuck on about 4 million km2 for over a month (and more than half the melt has happened), and the average difference over the last 10 years between that and the NSIDC September average is +0.40 million km2.

But :-
Ocean heat content?,
Low volume ?
Low thickness ?
The weather ?

[Juan C. García]

I went up, from 3.5-4 to 3.75-4.25.

[EgalSust]

Voted 4.5-5.0 following Slater et al June prediction.

[Archimid]

I went up to 3.5 to 4.

[slow wing]

I voted 3.0-3.5 million square kilometres.

I think the day minimum has more physical significance than the monthly one (what is the physical significance of a month?  ) so I just added 0.5 to my prediction in the day poll, where I explained my reasoning/guessing.

[magnamentis]

@slow wing

(what is the physical significance of a month?  )

either reconsider this (think again) or read it up online, matter off factly it's exactly the other way around the shorter the period the less significance when it comes to how meaningful that value is.
at least and always if we want to talk about changes of usually very long term states and usually very slow events.

i know it's OT but that-one stuck out to me.

[EgalSust]

Poll is closed, right?

Median prediction was between 3.5 and 4 Mkm², up a basket from June.

[EgalSust]

For the record, the SIPN/SIO July poll results are in for a while now. Median was 4.5, so you could say that in the ASIF system that would be 4.25-4.75, three baskets higher than the ASIF median.