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What will JAXA (ADS-NIPR-VISHOP) 2021 ASIE September daily minimum be?

Above 5.25 million km^2
0 (0%)
Between 4.75 and 5.25 million km^2
0 (0%)
Between 4.50 and 5.00 million km^2
0 (0%)
Between 4.25 and 4.75 million km^2
3 (9.1%)
Between 4.00 and 4.50 million km^2
18 (54.5%)
Between 3.75 and 4.25 million km^2
7 (21.2%)
Between 3.50 and 4.00 million km^2
2 (6.1%)
Between 3.25 and 3.75 million km^2
2 (6.1%)
Between 3.00 and 3.50 million km^2
1 (3%)
Between 2.75 and 3.25 million km^2
0 (0%)
Between 2.50 and 3.00 million km^2
0 (0%)
Between 2.25 and 2.75 million km^2
0 (0%)
Between 2.00 and 2.50 million km^2
0 (0%)
Under 2.00 million km^2
0 (0%)

Total Members Voted: 33

Voting closed: August 11, 2021, 01:04:53 AM

Author Topic: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll  (Read 2390 times)

Juan C. García

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The poll is for the minimum Daily Arctic sea ice extent in September 2021, as measured by ADS-NIPR-VISHOP (JAXA).

September mínimums have been:

Date                  Extent
                     (10^6 km2)
Sep 12, 2000      6.04
Sep 17, 2001      6.55
Sep 8, 2002        5.51
Sep 18, 2003      5.93
Sep 11, 2004      5.68
Sep 21, 2005      5.18
Sep 14, 2006      5.63
Sep 17, 2007      4.07
Sep 9, 2008        4.50
Sep 12, 2009      5.05
Sep 17, 2010      4.62
Sep 10, 2011      4.27
Sep 16, 2012      3.18
Sep 12, 2013      4.81
Sep 17, 2014      4.88
Sep 14, 2015      4.26
Sep 7, 2016        4.02
Sep 9, 2017        4.47
Sep 21, 2018      4.46
Sep 17, 2019      3.96
Sep 13, 2020      3.55

Order by lowest to highest:
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.

Freegrass

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #1 on: August 01, 2021, 01:58:39 AM »
I said outside the top 10, so that's more than 4,50. But to be safe, I voted between 4.25 and 4.75 million km2.
When factual science is in conflict with our beliefs or traditions, we cuddle up in our own delusional fantasy where everything starts making sense again...

icefisher

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #2 on: August 01, 2021, 02:47:33 AM »
Under normal weather conditions during August 4.3-4.4.  4.346 on September 16th.

Brigantine

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #3 on: August 01, 2021, 05:30:43 AM »
links to poll threads:
Month - PIOMAS / NSIDC / JAXA
June ___ link ____ link ____ link
July ____ link ____ link ____ link
August _ link ____ link ____ N/A

Brigantine

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #4 on: August 01, 2021, 05:51:12 AM »
I take my June prediction as an anchor, slide up 1.5 bins, and squash the spread into half the width.

4.00 - 4.50

Assumed bin chances: (>5.25) 0%; 0%; 1%; 6%; 23%; 43%; 20%; 5%; 2%; 0%; 0%; 0%; 0% (<2.50)

Stephan

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #5 on: August 03, 2021, 09:30:11 PM »
Unlike the years before I change my guess one bin higher to 3.75-4.25 M km² with a tendency that the value will be much closer to 4.25 than to 3.75.
It is too late just to be concerned about Climate Change

Dreaming of when ...

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #6 on: August 08, 2021, 06:07:37 AM »
Sticking with my June prediction of 4.0 - 4.5M km2. Back then i argued that a La Nina year wouldnt have the global oompf to break any records. I wasnt so sure after i checked that 2011 and 12 were on the back of one of the most extreme La Ninas on record. Safe to say the ice is toast the summer after the next global El Nino period.

Even so 2021 wont have to work too hard to make a top 5 lowest daily September extent. Even third spot is in contention if it dips a little below 4 million km2.

oren

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #7 on: August 09, 2021, 01:13:29 AM »
Upping one bin again to 3.75-4.25.

Bruce Steele

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #8 on: August 09, 2021, 02:14:35 AM »
2019 and 2020 I went fairly low and stayed with my vote through the season. I tried that this year but I just can’t see it going low this year. Two bins up to 4 - 4.5

Juan C. García

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #9 on: August 10, 2021, 05:51:22 AM »
Moving to the range 4.0 - 4.5 km2.

19 hours to vote or change your vote...   ;)
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.

Brigantine

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #10 on: August 10, 2021, 09:43:14 AM »
I take my June prediction as an anchor, slide up 1.5 bins, and squash the spread into half the width.

4.00 - 4.50

Assumed bin chances: (>5.25) 0%; 0%; 1%; 6%; 23%; 43%; 20%; 5%; 2%; 0%; 0%; 0%; 0% (<2.50)

Keeping my vote at 4.00 - 4.50, but updating the calculations to get there.
80%*[4.3 +/- 0.24Z] + 20%*[3.9 +/- 0.5Z]


Assumed bin chances: (>5.25) 0%; 0%; 3%; 15%; 33%; 29%; 12%; 4%; 2%; 1%; 1%; 0%; 0% (<2.50)

Brigantine

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #11 on: August 11, 2021, 08:56:54 AM »
A summary of June-July-August votes:

June - 54 votes total
  • 3.91 Upper Quartile (interpolated within bin)
  • 3.68 Median
  • 3.34 Lower Quartile
  • 24 or 44% voters at most can win (sum of 2 adjacent bins)
  • 7 poll options required to include 90% of votes
  • 0.57 Inter-quartile range


July - 47 votes total
  • 3.99 (+0.08) Upper Quartile
  • 3.78 (+0.10) Median
  • 3.53 (+0.19) Lower Quartile
  • 27 (+3) or 57% (+13) voters at most can win (sum of 2 adjacent bins)
  • 6 (-1) poll options required to include 90% of votes
  • 0.46 (-0.11) Inter-quartile range


August - 33 votes total
  • 4.30 (+0.39) Upper Quartile
  • 4.19 (+0.51) Median
  • 4.00 (+0.66) Lower Quartile
  • 25 (+1) or 76% (+32) voters at most can win (sum of 2 adjacent bins)
  • 4 (-3) poll options required to include 90% of votes
  • 0.30 (-0.27) Inter-quartile range

For a hypothetical final result of 3.99:
  • June
    • 7 votes (13%) too high
    • 23 votes (42%) correct
    • 24 votes (44%) too low
  • July
    • 5 votes (11%) too high
    • 27 votes (57%) correct
    • 15 votes (32%) too low
  • August
    • 21 votes (64%) too high
    • 9 votes (27%) correct
    • 3 votes (9%) too low

Brigantine

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #12 on: August 16, 2021, 01:16:57 PM »
I'm starting to get nervous. Getting down to 4.50 is looking challenging

JAXA ARCTIC SEA ICE EXTENT:  5,504,482 KM2 as at 15-Aug-2021

- Extent loss on this day 24k, 41 k less than the average loss on this day (of the last 10 years) of 65k [...]

On average 89.4% of extent losses from maximum to minimum done, and 30 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining extent loss (of the last 10 years) would produce a minimum in September 2021 of 4.44 million km2 [...]

To equal the linear trend 2021 minimum of 3.93 million KM2 requires further melting of  +1.58 million KM2, +48.6% more than the 10 year average remaining melt.

Killian

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #13 on: August 18, 2021, 08:19:56 AM »
I'm starting to get nervous. Getting down to 4.50 is looking challenging

I was just checking the JAXA chart and thought the same thing; if anything, 4.5+ seems most likely now.

Aluminium

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #14 on: August 19, 2021, 03:14:31 PM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 18th, 2021:
     5,429,749 km2, a small drop of -2,061 km2.
I'm starting to get nervous. Getting down to 4.50 is looking challenging
I'm not sure even about 5.00.

Juan C. García

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #15 on: August 20, 2021, 06:16:33 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 18th, 2021:
     5,429,749 km2, a small drop of -2,061 km2.
I'm starting to get nervous. Getting down to 4.50 is looking challenging
I'm not sure even about 5.00.
And I am starting to feel comfortable & happy!    ;)
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.

Brigantine

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #16 on: August 24, 2021, 11:08:57 AM »
"Above 5.25 million km^2" can be crossed out:

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 23rd, 2021:
     5,246,960 km2, a drop of -23,769 km2.

I'm expecting 2021 will track down like 2008 (almost) and end up in the 4.50 - 4.75 bin, but there's hope yet for my 4.00 - 4.50 vote.
« Last Edit: August 24, 2021, 11:56:27 AM by Brigantine »

Brigantine

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #17 on: August 31, 2021, 10:42:29 AM »
And into the 4.75 - 5.00 bin

Currently the 2021 minimum is in 14th place - below 2009 (and every year prior to 2007)

Years with JAXA extent loss after Aug 30 sufficient to put 2021 in each final bin:
(out of the 14 years since 2007, and out of the 20 years 1987-2006)
4.75 - 5.00 - 2015, 13/20
4.50 - 4.75 - 12/14, 7/20
4.25 - 4.50 - 2010, 0/20

So old normal would keep it in this bin, new normal would drop it down one, and 2010 would drop it 2 bins.

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 30th, 2021:
     4,987,614 km2, a drop of -18,875 km2.
     2021 is 11th lowest on record.

in August I gave 4.75-5.00 a 3% chance, and 4% for other bins at least this unlikely (total 7%)
In June and July, I gave it a 2% chance, and 5% for other bins at least this unlikely (total 7%)

I wouldn't be too comfortable with my estimates if it stays in this bin (still unlikely)
If it drops one more bin, I can live with it - total 14% for June/July and 38% for August
I'm still hoping for it to drop 2 more bins - 29% for June/July and August in my 33% 'most likely' bin.

EDIT: re Aluminium - fair point, it's tempting to read too much into 1 data point. If it was 1 out of 3, it would seem fine.
Also, here I'm focusing on whether my bin probabilities give enough room for uncertainty, rather than judging central estimates.
« Last Edit: August 31, 2021, 02:38:03 PM by Brigantine »

Aluminium

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #18 on: August 31, 2021, 12:35:56 PM »
I made this forecast in June. Anything above 4.50 seemed highly unlikely but definitely not impossible. I think, there is nothing wrong to have result at upper bound sometimes. Even if forecast was wrong, it means new knowledge. So what a reason to feel bad?

Brigantine

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #19 on: September 06, 2021, 08:17:46 AM »
JAXA Extent has dropped half a bin in the last 2 days, to 4,845 k

Dropping another 95 k into the 4.50 - 4.75 bin is entirely plausible, even likely.
(it happened in 13/18 years 1979-2006 and 12/14 years 2007-2020)

Dropping 345 k after Sep 5 into 4.25 - 4.50 is unprecedented.

Juan C. García

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Re: JAXA (ADS) 2021 Arctic SIE September daily minimum: August Poll
« Reply #20 on: September 13, 2021, 05:52:40 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

September 12th, 2021:
     4,612,915 km2, a drop of -35,031 km2.
     
Source: https://ads.nipr.ac.jp/vishop/#/extent.
At the current value, 2021 has become the 11th lowest on record.
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.