Arctic Sea Ice : Forum
Cryosphere => Arctic sea ice => Topic started by: Richard Rathbone on June 02, 2020, 01:18:43 PM
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This is a challenge which accumulates scores across all the monthly polls on September sea ice to come up with an overall rating of how good the predictions made are. In addition to making a prediction, entrants are required to rate their confidence in that prediction. The higher the confidence, the narrower the margin of error you are allowed, but the higher score you get if the September ice ends up where you predicted it (and the bigger penalty you take if you miss).
The scoring is intended to reward having a good idea of the margin of error in your prediction. You score low if you understate your accuracy, and get penalised heavily if you are overconfident.
Polls included are: JAXA daily minimum extent, NSIDC September average extent.
Others may be added if they fit the structure of the challenge.
Points are scored as follows:
Very High Confidence: 10 points if you pick the correct bin, -10 points for all other bins.
High Confidence: 6 points for the correct bin, 2 points if one bin out, -2 points if two bins out, -6 points for all other bins
Medium Confidence: 4 points for the correct bin, 2 points if one bin out, 1 point if two bins out, -1 if three bins out, -2 if four bins out, -4 points for all other bins
Low Confidence: 2 points for the correct bin, 1 point if within 3 bins, -1 point if 4-6 bins out, -2 points for all other bins
Very Low Confidence: 1 point if in the correct bin, no score (or penalty) for any other bin.
This is for a poll structure with overlapping 0.5 bins. When the result (or the prediction) is outside the range covered by a poll with overlapping 0.5 bins, points will be awarded by counting each extra 0.25 beyond the poll range as 1 bin. Under 2.0 is not a valid prediction for this challenge, but 0.5-1.0 is and counts as 6 bins below the 2.0-2.5 bin.
To enter, post prediction and confidence in this thread before the closing date of the poll. The deadline is midnight UK time on the day the poll closes.
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.
In order to help keep track of entries, please quote your previous entry when making entries in subsequent months.
Currently active polls are:
June poll for JAXA minimum. https://forum.arctic-sea-ice.net/index.php/topic,3109.0.html
June poll for NSIDC September average. https://forum.arctic-sea-ice.net/index.php/topic,3110.0.html
There is no requirement to enter for all polls or to match your choice in the predictions thread.
A challenge entry should look something like this
June JAXA : 0.0-0.5, VH
June NSIDC: 6.0-6.5, M
The mother of all GACs expels all ice from the arctic on Sept 1st but is met by a UN aerosol barrage that leads to massive refreeze by Sept 30th.
The 2018 challenge thread. https://forum.arctic-sea-ice.net/index.php/topic,2327.0.html
The 2019 thread. https://forum.arctic-sea-ice.net/index.php/topic,2749.0.html
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Thank you for posting the Challenge, Richard! :)
I will start with:
June JAXA: 3.50-4.00M km2 LC (low confidence)
June NSIDC: 4.00-4.50M km2 LC (low confidence)
As Gerontocrat put it, I should be a bin up on JAXA, at least. But the climate tendency is to have lower values. The ASI has been lucky on 2015-2019. A lot of bad starts that at the end, they were not that bad. So this year we are starting on the lower side again. Sooner or later, we will have a bad year on September.
On NSIDC, I see that 2007 started to refreeze very late. If that doesn't happen, my bet is that there is 0.5M km2 difference between JAXA daily value and NSIDC monthly average. So having 2007 and 2019 in the middle, is a good bet for me.
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JAXA: 3.25 - 3.75, high
NSIDC: 3.75 - 4.25, high
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JAXA: 3.75-4.25 (low)
NSIDC: 4.25-4.75 (high)
The JAXA daily low has much more variability, hence the lower confidence. The NSIDC September average has been more tightly confined, with four of the past five years falling within this bin. The exception was 2017 at 4.78, marginally above. Only 2012 was lower, which now appears to be a true outlier. Several other years were higher, but I am sticking with the trend towards lower averages.
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JAXA: 3.5-4.0 (medium)
NSIDC: 4.0-4.5 (high)
Both bets one bin below the highest probability range, to take into account downward surprises.
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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 think the difference of ± 0.25 M km² around the average of each bin is large enough to state both values as being "highly confident".
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June JAXA : 3.50-4.00M km2 LC 50%
June NSIDC' : 3.75-4.25M km2 LC 50%
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June JAXA: 3.75-4.25 sqMm. Medium Confidence
June NSIDC: 4-4.5 sqMM. Medium Confidence
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JAXA 4.10-4.60 hi
NSIDC 4.25-4.75 hi
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This year is hard for any predictions. However, in April two big bumblebees told me about strong melting season.
JAXA: 3.25-3.75, high.
NSIDC: 3.75-4.25 high.
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Almost no method has any skill this far out, and I usually don't see the ones that do until the June SIPN report comes out towards the end of the month, so at this stage the trend is the pick.
JAXA: 3.75-4.25 M
NSIDC: 4.25-4.75 M
PIOMAS: 4.25-4.75 M
This is one of the occasional years when NSIDC rounds up and JAXA rounds down so my separation of them by 0.3 comes in 2 bins apart rather than 1 bin.
Challenge entries for these polls close at midnight on June 11, about 52 hours from now.
Entries for PIOMAS September average may also be made, to keep things simple the deadline is also midnight on June 11.
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JAXA 4.10-4.60 hi
NSIDC 4.25-4.75 hi
PIOMAS 4.5-5.0 hi
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JAXA: 3.5-4.0 (medium)
NSIDC: 4.0-4.5 (high)
Both bets one bin below the highest probability range, to take into account downward surprises.
PIOMAS 4.25-4.75 High
Very little time left. I suggest anyone who voted and posted on the PIOMAS poll and doesn't post here in time gets an automatic entry of their vote at M confidence.
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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'm a little more aggressive in my guess than some, but I'm thinking we'll get some July and early August heat that will drive the number down. Pretty sure we won't beat 2012. <whistles a bit n the scary dark>
If not, everything shifts up one box.
If we get weather that seriously hammers the ice during peak, all bets are off, and I'm probably too high. Conditions are just that volatile that relatively modest swings in weather conditions can put us anywhere from 1st place to 5th.
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Final guesses:
JAXA: 3.75-4.25 Low
NSIDC: 4.25-4.75 High
PIOMAS: 4.00-4.50 Medium
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JAXA : 3.50-4.00M km2 LC Medium
NSIDC' : 3.75-4.25M km2 LC Medium
Piomas : 3.50-4.00M km2 LC Medium
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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)
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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)
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JAXA: 2.50 and 3.00M km2 MC (High confidence)
NSIDC: 3.00 and 3.50M km2 MC (High confidence)
PIOMAS: 3.25 and 3.75 km3 MC (Medium confidence)
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JAXA: 3.25-3.75, high.
NSIDC: 3.75-4.25 high.
PIOMAS: 4.25-4.75 high.
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JAXA: 3.25 - 3.75, high
NSIDC: 3.75 - 4.25, high
PIOMAS: 4.25-4.75, high
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We'll break the 2012 record with ease.
You need to put a number on that and state your confidence on that number in this thread.
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This poll has been added to my September challenge. However I am sticking to the same deadline as the extent polls, so there are just 52 hours left for PIOMAS challenge entries.
https://forum.arctic-sea-ice.net/index.php/topic,3113.0.html
The end of June challenge vote is approaching...
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Am I in time?
Jaxa: 3.0 - 3.5 high
NSIDC: 3.25 - 3.75 medium
PIOMAS: 3.25 - 3.75 medium
:D
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Am I in time?
Still over 9 hours to go. The polls closed at 1 a.m, so there's virtually a full day extra to the challenge deadline which is the midnight after the polls close.
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Now open for the 3 July polls.
July deadline for challenge entries is midnight on July 11th UK time, some 23 hours after the polls close.
Please quote your June entry (if any) in your July entry.
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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
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JAXA: 3.5-4.0 (medium)
NSIDC: 4.0-4.5 (high)
PIOMAS 4.25-4.75 High
July:
JAXA: 3.5-4.0 (high)
NSIDC: 3.75-4.25 (medium)
PIOMAS 3.75-4.25 (medium)
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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.
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JAXA 4.10-4.60 hi
NSIDC 4.25-4.75 hi
PIOMAS 4.5-5.0 hi
A lot has happened in the past month. The CAA looked pretty good a month ago and now looks like toast and now the CAB en fuego.
I'll try to stay on the optimistic side , but reality is what takes place when you are busy hoping for something else.
JAXA 3.75 - 4.25
NSIDC 4.00 - 4.50
PIOMAS 4.50 - 5.00
all hi.
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I don't know. The distribution of the ice, with such low amounts in the central seas and such high amounts in the peripheral seas, suggests that a lot will melt out in my very humble total guess of an opinion. Taking all my predictions down half a bin, but sticking to Medium.
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)
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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.
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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
Edit: corrected typo
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July JAXA : 3.50 - 4.00 km2 80% CL
July NSDIC : 3.75 - 4.25 km2 80% CL
July PIOMAS : 4.25 - 4.75 km2 80% CL
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July JAXA: 3.75-4.25 Medium
July NSIDC: 4.25-4.75 High
July PIOMAS: 4.00-4.50 High
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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)
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Thanks for doing this.
I missed June so have some catching up to do! :P
July poll for JAXA: 3.50-4.00M km2 VHC (Very high confidence)
July poll for NSIDC: 4.00-4.50M km2 VHC (Very high confidence)
July poll for PIOMAS: 3.75-4.25K km3 VHC (Very high confidence).
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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
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July JAXA : 3.0-3.5, H
July NSIDC: 3.25-3.75, H
July PIOMAS: 3.5 - 4.0, H
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Just a reminder:
July deadline for challenge entries is midnight on July 11th UK time, some 23 hours after the polls close.
Please quote your June entry (if any) in your July entry.
;)
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No regrets, i stand by my initial vote. :)
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I’m always quite pessimistic, so why change now?
JAXA: 2.0 - 2.5, High Confidence
NSIDC: 2.5 - 3.0, High Confidence
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.. says an optimist . :) b.c.
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.. says an optimist . :) b.c.
Haha, I'm optimistic about my pessimistic forecast!
I guess my rationale for the low forecast is centered around the absolutely astounding SST anomalies in the Laptev and Kara Seas. It has been consistently increasing through the summer days and I can only see the persistent high pressure adding to it.
Whenever the inevitable Low Pressure system moves through that area in the late season, the mixing of all that warm sea water into the CAB ice is going to absolutely wreck extents.
Also, I think extent drops are more indicative of phase changes than incremental melting. And phase changes cause unanticipated-ly large drops (2012 being almost a 1M lower in extent that the previous record low of 2007).
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Haha, I'm optimistic about my pessimistic forecast!
The circle is now full! ;D ;D ;D
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July -- JAXA: 3-3.5, H
July -- PIOMAS: 3.75-4.25, L
July -- NSIDC: 3.25-3.75, M
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JAXA: 1.95-2.45 (HIGH)
NSIDC: 2.20-2.70 (HIGH)
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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
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JAXA: 3.5-4.0 (medium)
NSIDC: 4.0-4.5 (high)
PIOMAS 4.25-4.75 High
July:
JAXA: 3.5-4.0 (high)
NSIDC: 3.75-4.25 (medium)
PIOMAS 3.75-4.25 (medium)
August:
JAXA: 3.25-3.75 (high)
NSIDC: 3.50-4.00 (medium)
PIOMAS 3.50-4.00 (high)
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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.
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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.
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JAXA: 1.95-2.45 (HIGH)
NSIDC: 2.20-2.70 (HIGH)
JAXA: 2.50-3.00 High
NSIDC: 2.75-3.25 Medium
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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
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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
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Increasing confidence.
JAXA: 3.75-4.25 Medium
NSIDC: 4.00-4.50 High
PIOMAS: 4.00-4.50 High
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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
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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
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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. :)
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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.
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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.
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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.
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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.
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Richard, if you wish you can PM me with any edits and I can insert them in.
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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.
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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
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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)
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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)
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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).
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Polls are closed but there are still almost 9 hours to make (or edit) an entry before the challenge deadline.
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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?
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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.
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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.
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https://forum.arctic-sea-ice.net/index.php/topic,3229.msg282351.html#msg282351
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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
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Going for Very High Confidence on JAXA was a mistake...
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I reckon you have a pretty good chance of getting away with it.
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>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.
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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
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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.
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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.
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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.