Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: Juan C. García on August 01, 2017, 03:33:18 AM

Title: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Juan C. García on August 01, 2017, 03:33:18 AM
ATTENTION:  This is the JAXA sea ice extent daily minimum.

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.

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

You can use the comment thread below to motivate your choice, but discuss various JAXA-ADS SIE data sets in this dedicated thread (https://forum.arctic-sea-ice.net/index.php/topic,230.msg123025.html#new).
You can also see the ADS updated graph  here (https://ads.nipr.ac.jp/vishop/#/extent).
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Juan C. García on August 01, 2017, 03:39:48 AM
Going up one bin: 3.50-4.00 km2.
I still don't have a clue of what is going to happen! Can go up or down...  ;)
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Paddy on August 01, 2017, 07:52:55 AM
Going back up a bin to 3.75 to 4.25. Thin ice makes lower predictions tempting, but otoh the glut of previous years in the 4.25 to. 4.50 bracket makes going up another bin tempting too. Overall this looks reasonable.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: oren on August 01, 2017, 08:15:58 AM
3.50-4.00, kind of giving up on a new record low, the IJIS track doesn't support it in any way. Still going for 2nd though, as PIOMAS thinness supports flash extent loss, and a GAC could easily arrive.
I have a feeling PIOMAS for end-July will report lower volume loss than normal, due to extra cloudiness, in which case I should probably increase my vote.
In my mind, IJIS is starting to win the war over PIOMAS... but it ain't over til its over.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Pavel on August 01, 2017, 08:37:39 AM
Between 3.75 and 4.25 It's 1 mln higher than my previous bets. I was suggesting the new record low is possible but sluggish ice retreat caused me to change opinion
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Richard Rathbone on August 01, 2017, 12:47:50 PM
Up 1. (to 4.25-4.75) The Slater projection is now high enough (4.85 for mid-September) that I considered going up 2 but I think there's more risk of a low value from late compaction than a high one from late dispersion.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Ned W on August 01, 2017, 01:54:30 PM
Today's version of the predict-o-matic says "4.23", up only trivially from the June 10th prediction of "4.21".  No real change in almost two months. 

I'll go with 4.0 to 4.5.

Edited on August 11th -- I revised my guess downward to the 3.75 to 4.25 bin, as the forecast drifted downward slightly from 4.2 to 4.1.  See new post below.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: DrTskoul on August 01, 2017, 10:43:18 PM
Same as previous month..3.75 - 4.25 ... back to lurking
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: magnamentis on August 02, 2017, 02:32:09 AM
3.5 - 4.0 2nd lowest, no change to my earlier votes
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Bruce Steele on August 02, 2017, 02:48:34 AM
Up one bin 3.75-4.25 
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: meddoc on August 02, 2017, 12:20:16 PM
3 Million km2.
Including Rubble, Ice Cubes & all the remaining Slush in the CAB.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: echoughton on August 02, 2017, 12:46:48 PM
Gonna be upmystic ...as usual... 4.50-5.00..thanks
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Neven on August 02, 2017, 01:01:16 PM
Same as last month, between 4.0 and 4.5.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Ned W on August 03, 2017, 12:50:11 PM
This is the time of year when the uncertainty around the drop-to-minimum really starts to narrow. 

Over the past 10 days, the standard deviation of the expected drop-to-min has fallen by 23%.  Over the next 10 days, it will fall by 51%.  By the time this month's poll closes, we should be able to narrow things down a lot.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FVTUF5V8.png&hash=c88500f935d14b75babbbbfe57675fb2)

Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: EgalSust on August 03, 2017, 02:37:46 PM
I'm guessing 4 to 4.5, same as July.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: jplotinus on August 03, 2017, 06:26:49 PM
For now I'll stick with season-long, low guess of 1.75-2.25. That's been my story, so may as well stick with it until just prior to close of poll. 😜
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: icefisher on August 04, 2017, 02:17:34 AM
Still expecting stormy weather but without a 2012 GAC sized cyclone.  4.08-4.3 mostly from late season compaction.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Paddy on August 04, 2017, 10:16:00 PM
For now I'll stick with season-long, low guess of 1.75-2.25. That's been my story, so may as well stick with it until just prior to close of poll. 😜

Anchoring yourself to a previous decision is a bit of a cognitive trap, imho. The only way to improve our decisions and guesses is to review old judgements when we gain the light of new evidence.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: RealityCheck on August 05, 2017, 12:55:28 AM
Moving down a bin to 3.75 to 4.25. Seems storms might make the difference.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Pmt111500 on August 05, 2017, 09:23:30 AM
For now I'll stick with season-long, low guess of 1.75-2.25. That's been my story, so may as well stick with it until just prior to close of poll. 😜

Anchoring yourself to a previous decision is a bit of a cognitive trap, imho. The only way to improve our decisions and guesses is to review old judgements when we gain the light of new evidence.
In the case of no new evidence presented I'm sticking to my vote.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: gerontocrat on August 05, 2017, 01:08:21 PM
For now I'll stick with season-long, low guess of 1.75-2.25. That's been my story, so may as well stick with it until just prior to close of poll. 😜

Anchoring yourself to a previous decision is a bit of a cognitive trap, imho. The only way to improve our decisions and guesses is to review old judgements when we gain the light of new evidence.
In the case of no new evidence presented I'm sticking to my vote.
EVIDENCE::-
To achieve a low of 2.25 million km2 requires extent loss in the remaining 40 days or so of the melt season of 3.8 million km2. The 10 year average was 1.9 million and the 2012 figure was 2.6 million.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: jplotinus on August 05, 2017, 04:22:05 PM
...and the loss on August 4th was ~140k
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: gerontocrat on August 06, 2017, 02:42:21 PM
My guess is 4.1 million km2, simply as a result of playing the percentage game (see table below). The underlying assumption is that this is turning out to be a very average year for total extent loss, though fascinating in many other ways.


Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Sterks on August 06, 2017, 04:01:53 PM
I maintain my vote in 3.75 to 4.25 mill km2, that is, in line with the new standards, 2016, 2015, which are about the same extent of the once outlier 2007.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: DavidR on August 09, 2017, 07:48:54 AM
I've moved up slightly to 3.50 to 4.00.

If the decline from today matches the trend value, which is about 1.80M, the result will be about 3.86M. I expect the decline to to be significantly higher much closer to the 2012 drop to minimum of 2.015M. It  wouldn't surprise at all if 2017 closes the gap with 2012 between now and the minimum because of the state of the ice.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Paddy on August 09, 2017, 08:30:11 AM
Quote
In the case of no new evidence presented I'm sticking to my vote.

For me, the main evidence which pushed my estimates higher was the slow volume loss we've had that brought volume figures back in line with previous years.  Before, when we were at a clear record low winter / spring volume, it seemed reasonable to forecast a record low summer extent. Now, not so much, even with the past few days of relatively steep extent loss.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: RikW on August 09, 2017, 08:46:16 AM
I changed my vote (0.25-0.75 :P ) to a more logical one. I think we will get below 4.00, but not too much, so going for 3.50-4.00.

I think it will be a little worse than most expect/hope, seeing the state of the ice, the weather predictions and the effect of current weather on the ice.

IJIS is quickly catching up and moving towards 2nd position quickly. And 2nd position means below 4.02, but how much will be the question...
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Archimid on August 09, 2017, 02:01:57 PM
I'm going with my previous guess. 3.0 to 3.5.  I think the daily low will be record or near record low. However after minimum, which could be early, I expect vigorous growth for a few weeks. To attempt to capture that I will go up several notches on the monthly poll to 4.25-4.75
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Juan C. García on August 10, 2017, 08:10:29 PM
Less than 2 days, to make your vote or change it!  ;)
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: jplotinus on August 10, 2017, 09:24:24 PM
Less than 2 days, to make your vote or change it!  ;)

The PAC over the Chukchi-Beaufort region has been churning non-stop for just about all of August from what I can gather. Further, it also appears the CAA garlic press may be due for an onslaught of flushing winds over the course of the next few days; as the poll period closes.

To reach the extremely low level of 1.75-2.25m km2 that I've been voting for, the cyclones will need to remain as persistent as they have been and the thinness of the ice overall will have to precipitate unprecedented extent declines during the remainder of August.

I don't think the conditions will be extreme enough to cause unprecedented losses, but I will wait one more day before coming to my sen...err, casting a vote. 😜


Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: philiponfire on August 11, 2017, 05:10:42 AM
June I went for 2.75-3.25. then I wimped out and went up to 3.00-3.50 for July. As we reach the end of August voting I am going back to my original vote. 2.75-3.35 at the end of the day the facts still remain that the year started with very thin ice. There is still time for a huge area to go from being fractured spread out ice to being open water. Everything left to play for. MASIE has been lower than 2012 right up until a few weeks back then it went high but only a few 100 thousand sq km. Now that has all gone again and 2017 is back in the lead.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: jplotinus on August 11, 2017, 12:56:09 PM
The jaxa August 10th decline was small(ish), despite the PAC. The factors I am relying on to foretell the minimum no longer support the extreme low of 1.75-2.25. It's beginning to become clearer that 2017 will group with 2007,2015-16. I think 2017 will come in as the new runner-up, at just below 4.00.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Ned W on August 11, 2017, 01:46:02 PM
The predict-o-matic's forecast has declined slightly from 4.2 to 4.1, but in general it continues to follow the expected values very closely:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FvEOliDb.png&hash=f8a7950857e30b15d94bca0cdbc34246)

Since the day it started (June 10) the forecast has been boringly consistent.  The most likely value has ranged from a low of 4.02 to a high of 4.30.  The 95% confidence interval has narrowed, and currently is (3.71, 4.43):

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FfTGvPhl.png&hash=915b0e6d4be409ce608bd696d9050411)

A new record, or indeed anything below 3.7, seems extremely improbable at this point.  It boggles my mind a bit that some people continue to offer predictions below 3.5.

Here's a comparison of extent on Day 223 vs the ultimate minimum, for the years 2007-2016, with the mean forecast and 95% confidence interval in red:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FXs8DylI.png&hash=968ea3905c5167dcb1ff629193ad0175)

The forecast has been hovering in the area of overlap between the 3.75-4.25 and 4.0-4.5 bins.  I've waffled over which one to choose, but I'm returning to my July prediction of 3.75-4.25.

Odds for each bin, from the predict-o-matic:

4.75 and higher:  0%
4.50 to 5.00: 1%
4.25 to 4.75: 16%
4.00 to 4.50: 65%
3.75 to 4.25: 80%
3.50 to 4.00: 34%
3.25 to 3.75: 1%
3.5 and lower: 0%

Total sums to over 100% because of overlapping bins.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Juan C. García on August 11, 2017, 02:25:21 PM
Neven ASIB:

Quote
Last year I was of the opinion that the Arctic (and thus the rest of the world) had dodged a bullet, thanks to a slow start of the melting season. This year I'd say it has dodged a cannonball given the record low maximum and the record low volume (by a large margin) for months on end.

I'm going up another bin, to 3.75-4.25 km2.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: weatherdude88 on August 11, 2017, 04:20:12 PM
June I went for 2.75-3.25. then I wimped out and went up to 3.00-3.50 for July. As we reach the end of August voting I am going back to my original vote. 2.75-3.35 at the end of the day the facts still remain that the year started with very thin ice. There is still time for a huge area to go from being fractured spread out ice to being open water. Everything left to play for. MASIE has been lower than 2012 right up until a few weeks back then it went high but only a few 100 thousand sq km. Now that has all gone again and 2017 is back in the lead.

2006-6914858.83 Kilometers Squared
2007-5658628.48 Kilometers Squared
2008-6957847.31 Kilometers Squared
2009-6649893.15 Kilometers Squared
2010-6326294.13 Kilometers Squared
2011-6230654.16 Kilometers Squared
2012-6308909.23 Kilometers Squared
2013-6528327.55 Kilometers Squared
2014-6815819.12 Kilometers Squared
2015-6446197.31 Kilometers Squared
2016-6335948.88 Kilometers Squared
2017-6301329.71 Kilometers Squared

For day 221 (day 222 will update today), the MASIE value is currently third place (ahead of 2007 and 2011).

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/masie_4km_allyears_extent_sqkm.csv

I find your illogical reasoning for a record JAXA sea ice extent minimum value using MASIE data underwhelming.


Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: iceman on August 11, 2017, 07:37:45 PM
Anchoring yourself to a previous decision is a bit of a cognitive trap, imho. The only way to improve our decisions and guesses is to review old judgements when we gain the light of new evidence.

Yeah, I feel those jaws on my brain: still seeking reasons that thickness distribution (rather than volume per se) will push extent down.  Came up with: storm-induced dispersion will first slow extent loss, then wave action and bottom melt will prolong it, resulting in a late low.
    That's not overwhelmingly convincing, so going with 3.75 to 4.25 for a podium finish.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: VeliAlbertKallio on August 11, 2017, 10:38:34 PM
I went for my final for 3.75 m km2 max.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: slow wing on August 12, 2017, 04:09:34 AM
I missed the close as wanted to see what the storm would do  :-\

Would have chosen 3.0-3.5 million square kilometres.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: philiponfire on August 14, 2017, 11:43:02 AM


2006-6914858.83 Kilometers Squared
2007-5658628.48 Kilometers Squared
2008-6957847.31 Kilometers Squared
2009-6649893.15 Kilometers Squared
2010-6326294.13 Kilometers Squared
2011-6230654.16 Kilometers Squared
2012-6308909.23 Kilometers Squared
2013-6528327.55 Kilometers Squared
2014-6815819.12 Kilometers Squared
2015-6446197.31 Kilometers Squared
2016-6335948.88 Kilometers Squared
2017-6301329.71 Kilometers Squared

For day 221 (day 222 will update today), the MASIE value is currently third place (ahead of 2007 and 2011).

ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/masie_4km_allyears_extent_sqkm.csv

I find your illogical reasoning for a record JAXA sea ice extent minimum value using MASIE data underwhelming.
[/quote]
Clearly you do not have  a clue what my reasoning is. I made no mention of any previous years other than 2012. I chose to talk about what I consider to be the RELEVANT data. In my opinion it is beyond doubt that the ice is in a terminal decline with an approximately five year cycle superimposed on it. Since it is apparent that things are changing rapidly I see no reason to look back as far as 2007. Well done you for spotting that in that year the ice was lower during August. I stand by my thinking however much you are underwhelmed. I will not respond again.
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Feeltheburn on August 30, 2017, 01:30:46 AM
Too bad I missed this more recent poll. I checked my vote from June, which was 4.5-4.75 million km2, with only 1 vote above me. In July, I changed my vote to 4-4.5 million km2. Looks likes I will finish slightly in the money (should have gone with 4.25-4.75)
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: jplotinus on September 10, 2017, 02:57:48 PM
4.47 as of 9/9/17. The end is near (maybe). 😯
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Jim Pettit on September 16, 2017, 03:46:26 PM
4.47 as of 9/9/17. The end is near (maybe). 😯

And that 4.47 indeed looks like the final. If that sticks--and I'll lay good money on that being the bottom--the 12.4% who chose bucket #5 (Between 4.00 and 4.50 million km2) made it--just barely--while the 7.6% who picked bucket #4 (Between 4.25 and 4.75 million km2) were almost dead-on in the middle. <Pats self on back>
Title: Re: JAXA 2017 Arctic SIE September daily minimum: August poll
Post by: Susan Anderson on September 18, 2017, 06:44:38 PM
Interesting. I'm wondering if this holds any surprises ...
https://earth.nullschool.net/#current/wind/surface/level/overlay=temp/orthographic=315.74,94.92,474