Support the Arctic Sea Ice Forum and Blog

Author Topic: September predictions challenge 2020  (Read 5592 times)

glennbuck

  • Frazil ice
  • Posts: 331
    • View Profile
  • Liked: 113
  • Likes Given: 30
Re: September predictions challenge 2020
« Reply #50 on: August 02, 2020, 05:23:43 PM »
JAXA:  1.95-2.45 (HIGH)
NSIDC:  2.20-2.70 (HIGH)

JAXA:  2.50-3.00 High
NSIDC:  2.75-3.25 Medium
« Last Edit: August 02, 2020, 05:29:32 PM by glennbuck »

KenB

  • New ice
  • Posts: 66
    • View Profile
  • Liked: 26
  • Likes Given: 7
Re: September predictions challenge 2020
« Reply #51 on: August 02, 2020, 05:36:00 PM »
July JAXA : 3.0-3.5, H
July NSIDC: 3.25-3.75, H
July PIOMAS:  3.5 - 4.0, H

August JAXA : 3.0-3.5, H
August NSIDC: 3.25-3.75, H
August PIOMAS:  3.5 - 4.0, H

"When the melt ponds drain apparent compaction goes up because the satellite sees ice, not water in ponds." - FOoW

Stephan

  • Nilas ice
  • Posts: 1329
    • View Profile
  • Liked: 467
  • Likes Given: 229
Re: September predictions challenge 2020
« Reply #52 on: August 02, 2020, 06:08:16 PM »
I repeat the values I gave for the two polls:

JAXA Sep min. 3.75-4.25 M km² confidence high
NSIDC Sep ave. 4.00-4.50 M km² confidence high

I confirm the bins from July and their confidence.
As for PIOMAS Sep volume I stay with the 4.25-4.75 k km³ bin, high confidence.

No change in here neither in the polls:
JAXA Sep min. 3.75-4.25 M km² high confidence
NSIDC Sep ave. 4.00-4.50 M km² high confidence
PIOMAS Sep vol. 4.25-4.75 k km³ high confidence
It is too late just to be concerned about Climate Change

The Walrus

  • Grease ice
  • Posts: 611
    • View Profile
  • Liked: 84
  • Likes Given: 26
Re: September predictions challenge 2020
« Reply #53 on: August 03, 2020, 07:31:21 PM »
Increasing confidence.

JAXA:   3.75-4.25  Medium
NSIDC:   4.00-4.50  High
PIOMAS:  4.00-4.50  High

PragmaticAntithesis

  • New ice
  • Posts: 90
    • View Profile
  • Liked: 25
  • Likes Given: 84
Re: September predictions challenge 2020
« Reply #54 on: August 04, 2020, 02:50:51 PM »
June JAXA: 3.75-4.25 sqMm. Medium Confidence

June NSIDC: 4-4.5 sqMM. Medium Confidence

July JAXA: 3.5-4 sqMM. Medium Confidence

July NSDIC: 3.75-4.25 sqMM. Medium Confidence

July PIOMAS: 4,250-4,750 km3. Medium Confidence

Go big or go home!

August JAXA: 3.25-3.75 sqMM Very High Confidence

August NSDIC: 3.5-4.0 sqMM High Confidence

August PIOMAS: 3,750-4,250 km3 Very High Confidence
A single seed in the right place can sprout an entire forest.

Richard Rathbone

  • Grease ice
  • Posts: 787
    • View Profile
  • Liked: 124
  • Likes Given: 11
Re: September predictions challenge 2020
« Reply #55 on: August 04, 2020, 08:02:47 PM »
June
JAXA: 3.75-4.25 M
NSIDC: 4.25-4.75 M
PIOMAS: 4.25-4.75 M
July
JAXA 3.5 - 4.0 M
NSIDC 4.0 - 4.5 M
PIOMAS 4.25 - 4.75 H
PIOMAS (the prediction version used for SIPN entries) said the volume was arranged in a way that is bad for September extent at the beginning of June and it remained bad at the beginning of July.  SPIE (the Slater model) says the ice area was arranged in a way that was good for September extent at the beginning of July and its not bad now. Volume now would be the best way to resolve that difference, but I don't get to see what the PIOMAS prediction was until the SIPN report comes out at the end of the month. I think I have to have 3.5 inside my confidence interval because of PIOMAS, but I don't think it can smash 2012 so a 3.5-4 VH, or 3.75-4.25 H for NSIDC. If they were equally timely, I'd take volume signal over area signal, but there is no way I can have 4.25 outside the confidence interval based on what SPIE is saying now.

NSIDC 3.75-4.25 H

JAXA I just lop 0.3 off and round the uncertainty up from my NSIDC consideration and then see how that looks compared to the gerontocrat plume. It looks very 3.5-4 ish to my eyes but there is no way I give a VH to JAXA if I've stuck at H on NSIDC.

JAXA 3.5-4.0 H

PIOMAS anomaly follows a pretty consistent pattern 9 months out of 10. Is the next month going to be the unusual one? The bin has to be 4.25 - 4.75 and I think the risk of 4.75-5 is small but I'm not so confident about 4-4.25. The tipping point for VH is 25% risk. Its a close call. I reckon PIOMAS is more predictable than the other measures but I haven't ever paid much attention to the monthly average on PIOMAS rather than the daily volume, so I'm sticking at H.

PIOMAS 4.25-4.75 H

Aluminium

  • Grease ice
  • Posts: 720
    • View Profile
  • Liked: 640
  • Likes Given: 383
Re: September predictions challenge 2020
« Reply #56 on: August 05, 2020, 08:58:05 AM »
JAXA: 3.25-3.75 high.
NSIDC: 3.75-4.25 high.
PIOMAS: 4.25-4.75 high.

JAXA: 3.25-3.75 high.
NSIDC: 3.75-4.25 high.
PIOMAS: 4.0-4.5 high.

JAXA: 3.25-3.75 high.
NSIDC: 3.75-4.25 very high.
PIOMAS: 3.75-4.25 very high. :)

Paddy

  • Grease ice
  • Posts: 668
    • View Profile
  • Liked: 57
  • Likes Given: 60
Re: September predictions challenge 2020
« Reply #57 on: August 07, 2020, 08:44:10 AM »
June predictions:
JAXA: 3.75 to 4.25 (Medium confidence)
PIOMAS: 4 to 4.5 (Medium confidence)
NSIDC: 4.25 to 4.75 (Medium confidence)

...
July predictions:
JAXA: 3.5 to 4.0 (Medium confidence)
PIOMAS: 3.75 to 4.25 (Medium confidence)
NSIDC: 4.0 to 4.5 (Medium confidence)

August predictions:
JAXA: 3.5 to 4.0 (High confidence)
PIOMAS: 3.75 to 4.25 (High confidence)
NSIDC: 3.75 to 4.25 (High confidence)

I'm not actually at all high in confidence, but thar's the way this game is scored.

Already thinking I went too low here. Oh well, should have waited.

binntho

  • Nilas ice
  • Posts: 1481
    • View Profile
  • Liked: 490
  • Likes Given: 114
Re: September predictions challenge 2020
« Reply #58 on: August 07, 2020, 09:03:34 AM »
The last week of low extent losses does not really say very much about what the final outcome will be. Very low extent losses at this time and with the ice in the state that it is couid simply be setting up for major losses next week.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

Juan C. García

  • Nilas ice
  • Posts: 2019
    • View Profile
  • Liked: 960
  • Likes Given: 687
Re: September predictions challenge 2020
« Reply #59 on: August 07, 2020, 11:18:49 AM »
Already thinking I went too low here. Oh well, should have waited.
As I understand this challenge, there is still time to change your August prediction, if you want to do it.
On the 3 polls we have the chance to change them until the first hours on August 11th. It will be convenient if Richard Rathbone tell us the deadline on this challenge.
« Last Edit: August 07, 2020, 11:24:37 AM by Juan C. García »
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.

Richard Rathbone

  • Grease ice
  • Posts: 787
    • View Profile
  • Liked: 124
  • Likes Given: 11
Re: September predictions challenge 2020
« Reply #60 on: August 07, 2020, 01:43:25 PM »
Already thinking I went too low here. Oh well, should have waited.
As I understand this challenge, there is still time to change your August prediction, if you want to do it.
On the 3 polls we have the chance to change them until the first hours on August 11th. It will be convenient if Richard Rathbone tell us the deadline on this challenge.

Its in both the first post and a post on August 1st. Midnight UK time on the day the polls close which is about 20 hours after the polls close.

Forum rules changed so I can't edit the first post any more which is why its only a generic statement in the rules and the specific time is easy to miss in the middle of the thread now. I bump the thread with a reminder when its getting close too.

The rules do allow you to change up until the deadline. I might change that next year since the forum has restricted edits since I first ran this and it caught me out this year. Edit your original post if you can, otherwise make a fresh post quoting your earlier ones.

oren

  • Moderator
  • First-year ice
  • Posts: 6152
    • View Profile
  • Liked: 2219
  • Likes Given: 1869
Re: September predictions challenge 2020
« Reply #61 on: August 07, 2020, 06:03:56 PM »
Richard, if you wish you can PM me with any edits and I can insert them in.

Juan C. García

  • Nilas ice
  • Posts: 2019
    • View Profile
  • Liked: 960
  • Likes Given: 687
Re: September predictions challenge 2020
« Reply #62 on: August 07, 2020, 06:06:37 PM »
Its in both the first post and a post on August 1st. Midnight UK time on the day the polls close which is about 20 hours after the polls close.

So the deadline is August 11th:

Editing to change a prediction is allowed at any time before the deadline. Editing for any reason after the deadline will result in disqualification of that entry.
Open for August entries. Oren provides a nice example of the preferred way to format them in the previous post.

Deadline is midnight UK time on August 11th which is approximately 20 hours after the polls close.
« Last Edit: August 07, 2020, 07:26:36 PM by Juan C. García »
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.

glennbuck

  • Frazil ice
  • Posts: 331
    • View Profile
  • Liked: 113
  • Likes Given: 30
Re: September predictions challenge 2020
« Reply #63 on: August 07, 2020, 07:59:46 PM »
JAXA:  1.95-2.45 (HIGH)
NSIDC:  2.20-2.70 (HIGH)


JAXA:  2.50-3.00 High
NSIDC:  2.75-3.25 Medium

JAXA:  2.75-3.25 High
NSIDC:  3.00-3.50 High

« Last Edit: August 07, 2020, 09:15:25 PM by glennbuck »

Paddy

  • Grease ice
  • Posts: 668
    • View Profile
  • Liked: 57
  • Likes Given: 60
Re: September predictions challenge 2020
« Reply #64 on: August 07, 2020, 11:46:13 PM »
June predictions:
JAXA: 3.75 to 4.25 (Medium confidence)
PIOMAS: 4 to 4.5 (Medium confidence)
NSIDC: 4.25 to 4.75 (Medium confidence)

...
July predictions:
JAXA: 3.5 to 4.0 (Medium confidence)
PIOMAS: 3.75 to 4.25 (Medium confidence)
NSIDC: 4.0 to 4.5 (Medium confidence)

August predictions:
JAXA: 3.5 to 4.0 (High confidence)
PIOMAS: 3.75 to 4.25 (High confidence)
NSIDC: 3.75 to 4.25 (High confidence)

I'm not actually at all high in confidence, but thar's the way this game is scored.

Please edit up my August nsidc prediction to 4.0 to 4.5 (confidence still laughably high). Thank you for accepting edits even without the ability to edit posts!

EDIT: Actually, please could I edit them all up half a bin:

August JAXA 3.75 - 4.25 (High confidence)
August PIOMAS: 4.0 to 4.5 (High confidence)
August nsidc  4.0 to 4.5 (High confidence)
« Last Edit: August 09, 2020, 07:15:29 PM by Paddy »

Juan C. García

  • Nilas ice
  • Posts: 2019
    • View Profile
  • Liked: 960
  • Likes Given: 687
Re: September predictions challenge 2020
« Reply #65 on: August 10, 2020, 06:11:22 AM »
June poll for JAXA: 3.50-4.00M km2 MC (Medium confidence)
June poll for NSIDC: 4.00-4.50M km2 MC (Medium confidence)
June poll for PIOMAS: 4.00-4.50K km3 MC (Medium confidence)
July poll for JAXA: 3.50-4.00M km2 HC (High confidence)
July poll for NSIDC: 3.75-4.25M km2 HC (High confidence)
July poll for PIOMAS: 3.75-4.25K km3 HC (High confidence)
August poll for JAXA: 3.50-4.00M km2 HC (High confidence)
August poll for NSIDC: 4.00-4.50M km2 HC (High confidence)
August poll for PIOMAS: 3.75-4.25K km3 HC (High confidence)
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.

slow wing

  • Grease ice
  • Posts: 819
    • View Profile
  • Liked: 156
  • Likes Given: 495
Re: September predictions challenge 2020
« Reply #66 on: August 10, 2020, 02:35:58 PM »
Dropping down half a bin on all 3 as the high stayed high & the sun kept shining, & then the wind blew in the Beaufort.

August poll for JAXA: 3.25-3.75M km2 VHC (Very high confidence)
August poll for NSIDC: 3.75-4.25M km2 VHC (Very high confidence)
August poll for PIOMAS: 3.50-4.00K km3 VHC (Very high confidence).

Richard Rathbone

  • Grease ice
  • Posts: 787
    • View Profile
  • Liked: 124
  • Likes Given: 11
Re: September predictions challenge 2020
« Reply #67 on: August 11, 2020, 04:08:55 PM »
Polls are closed but there are still almost 9 hours to make (or edit) an entry before the challenge deadline.

Richard Rathbone

  • Grease ice
  • Posts: 787
    • View Profile
  • Liked: 124
  • Likes Given: 11
Re: September predictions challenge 2020
« Reply #68 on: August 20, 2020, 01:34:39 AM »
https://nsidc.org/arcticseaicenews/
NSIDC is publishing some of its predictions in their mid-August news, so there's a chance to see some of their SIPN entries before the SIPN report is published at the end of the month, and a couple based on the latest (Aug 17th) data.

Aug 17th is 4.23+-0.19 by the gerontocrat plume style method, which is 4-4.5 VH in challenge terms.
Aug 1st is 3.93+-0.36 which I'd translate to 3.75-4.25 H
The Slater method is 4.48 (they don't quote a range, but Slater reckoned it beat the plume method), so that would be 4.25-4.75 VH

Anyone feeling nervous about how their predictions are doing yet?

Paddy

  • Grease ice
  • Posts: 668
    • View Profile
  • Liked: 57
  • Likes Given: 60
Re: September predictions challenge 2020
« Reply #69 on: August 20, 2020, 05:54:46 AM »
Quote from: Richard Rathbone
Anyone feeling nervous about how their predictions are doing yet?

Slightly reassured that their predictions roughly match my own, but if the current rate of loss continues, and/or if storm Ellen hits the ice, both they and I may have been a bit on the high side.

The Walrus

  • Grease ice
  • Posts: 611
    • View Profile
  • Liked: 84
  • Likes Given: 26
Re: September predictions challenge 2020
« Reply #70 on: August 20, 2020, 03:19:23 PM »
https://nsidc.org/arcticseaicenews/
NSIDC is publishing some of its predictions in their mid-August news, so there's a chance to see some of their SIPN entries before the SIPN report is published at the end of the month, and a couple based on the latest (Aug 17th) data.

Aug 17th is 4.23+-0.19 by the gerontocrat plume style method, which is 4-4.5 VH in challenge terms.
Aug 1st is 3.93+-0.36 which I'd translate to 3.75-4.25 H
The Slater method is 4.48 (they don't quote a range, but Slater reckoned it beat the plume method), so that would be 4.25-4.75 VH

Anyone feeling nervous about how their predictions are doing yet?

Combining all three, we have a very wide range of 3.75 - 4.75.  At 4.0 - 4.5, my guess sits right in the middle and corresponds with the gerontocrat plume style.  Not nervous yet.

igs

  • Guest
« Last Edit: August 20, 2020, 07:39:23 PM by oren »

Richard Rathbone

  • Grease ice
  • Posts: 787
    • View Profile
  • Liked: 124
  • Likes Given: 11
Re: September predictions challenge 2020
« Reply #72 on: September 01, 2020, 04:36:38 PM »

June SIPN report has some interesting predictions.
https://www.arcus.org/sipn/sea-ice-outlook/2020/june 

University of Washington (PIOMAS in forecast mode) is making the lowest forecast of all SIPN entries, 3.2 +- 0.4
CPOM (Schroeder's melt pond statistic) is the statistical method making the lowest prediction, 3.8 +-0.5 with a 30% chance of a new record
The US Navy has the highest prediction 6.2 +-0.7
Nico Sun (posts here as Tealight) predicts 4.09-5.41 median 4.84 on the basis of his albedo model.
The UCL team (similar type of statistical model as Slater's) forecasts 3.96 +-0.34

July SIPN entries (based on June data) are now published.
PIOMAS forecast still thinks its going to be really low 3.35 +-0.4 though there is now one other model forecasting lower.
CPOM has backed off (due to low melt pond formation in early June) and is now saying 4.3 +-0.5
The US Navy still has the highest prediction but its dropped to 5.2 median 4.9-5.8 range
Nico Sun drops to median 4.41 range 3.96-4.74
The Slater model is one of the highest at 4.64
The UCL team is up to 4.3 +-0.27

August SIPN report is now out. Lots of regression to the mean going on.
PIOMAS forecast jumps up to 3.81 and is now the third lowest forecast.
US Navy drops to 4.2
Nico Sun tightens to 4.36 range 4.13-4.50
The Slater model drops to 4.48, it doesn't look like a good year for this technique.
The UCL variant sticks at 4.3 though its actually slightly more uncertain than it was in July! +-0.3

PragmaticAntithesis

  • New ice
  • Posts: 90
    • View Profile
  • Liked: 25
  • Likes Given: 84
Re: September predictions challenge 2020
« Reply #73 on: September 02, 2020, 09:49:11 PM »
Going for Very High Confidence on JAXA was a mistake...
A single seed in the right place can sprout an entire forest.

Richard Rathbone

  • Grease ice
  • Posts: 787
    • View Profile
  • Liked: 124
  • Likes Given: 11
Re: September predictions challenge 2020
« Reply #74 on: September 03, 2020, 12:11:51 AM »
I reckon you have a pretty good chance of getting away with it.

Aluminium

  • Grease ice
  • Posts: 720
    • View Profile
  • Liked: 640
  • Likes Given: 383
Re: September predictions challenge 2020
« Reply #75 on: September 03, 2020, 06:19:06 AM »
>50% is enough to have positive mathematical expectation. Even if High Confidence was a better choice, 3.25-3.75 seems the most probable at this time.

Aluminium

  • Grease ice
  • Posts: 720
    • View Profile
  • Liked: 640
  • Likes Given: 383
Re: September predictions challenge 2020
« Reply #76 on: September 03, 2020, 08:30:31 PM »
Possible PIOMAS September average based on previous years:

2000   4,314
2001   4,256
2002   4,278
2003   4,255
2004   4,300
2005   4,159
2006   4,110
2007   4,223
2008   3,894
2009   4,139
2010   4,257
2011   4,202
2012   4,174
2013   4,257
2014   4,126
2015   4,218
2016   4,203
2017   4,324
2018   4,217
2019   4,347

gerontocrat

  • First-year ice
  • Posts: 9043
    • View Profile
  • Liked: 3548
  • Likes Given: 26
Re: September predictions challenge 2020
« Reply #77 on: September 04, 2020, 01:37:16 PM »
PIOMAS - IFF volume loss to minimum and the volume gain to end of September is at the average of the last 10 years, the PIOMAS September Monthly Average will be 4.229 thousand km3, almost exactly on the value calculated from the linear trend.

CAVEAT - but it won't.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Richard Rathbone

  • Grease ice
  • Posts: 787
    • View Profile
  • Liked: 124
  • Likes Given: 11
Re: September predictions challenge 2020
« Reply #78 on: September 04, 2020, 03:18:32 PM »
I lose 10 points on PIOMAS between 4.251 and 4.249 and thats probably going to the wire. I'd sell my position at 6 points or buy at 3 at the moment.

jdallen

  • Young ice
  • Posts: 3231
    • View Profile
  • Liked: 496
  • Likes Given: 203
Re: September predictions challenge 2020
« Reply #79 on: September 06, 2020, 10:28:02 PM »
This is a big dice roll so early in the season, but I'll throw my hat in.

JAXA: 3.75-4.25     High
NSIDC: 4.0-4.5      High
PIOMAS: 3.75-4.25 Medium

I am surprised, that my estimates may actually turn out to be too *high*.

NSIDC is below 4.0 million km2
Jaxa may pass 3.75 shortly.
I may still be in play with PIOMAS.

I'm pretty shocked.
This space for Rent.