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Arctic Sea Ice Extent, Area, and Volume


ORH_wxman
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5 hours ago, ORH_wxman said:

I did make a prediction for NSIDC extent back in my prediction post (I went with 4.8 million sq km). Extent is a little harder to predict because compaction makes a big difference unlike area where compaction wouldn’t change a whole lot. 

In the short term (0-96h), the pattern is pretty good for compaction but the longer term ensembles aren't…however, things can always change in the arctic pretty quickly beyond 5 days. 
 

I personally forecasted a bit higher extent than I might normally would for a 3.1 million sq km area prediction (4.6 or 4.7 million sq km would be more in line with 3.1 area) due to the stronger buffer in the Chukchi region this year and lower area in Hudson Bay which melts out fully anyway…the latter was driving down the area numbers in late June. 
 

The mean pattern in August will likely have a big say in the final extent. If we get a lot of high pressure over the basin (esp skewed a bit toward North American side), then we’ll see a lot of compaction and lower extent…but if we see a lot of low pressure, it will keep the ice dispersed and the extent will stay higher by the time we get to the min in early or mid September. 

Oh duh. Yeah, it's right there. Thanks!

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 The 7/14 Arctic sea ice area has fallen 2.05 msk since 6/29 or 137k/day. That far exceeds (by 500-600k) the avg fall for that period in the 2010s and 2000s. The years that ended up with the lowest min area are 2012, 2020, 2016, and 2019 per this:

sea_ice_min_graph_only_2022.1349.png

 The drop for 6/29-7/14 in 2023 exceeds that for 2012 by ~500k, for 2020 by ~200k, for 2016 by ~350k, and for 2019 by ~300k.

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Update:

On 7/16, NSIDC area was at 5.42 million sqkm. Here's where other years were on the same date:

2022: +420k

2021: +130k

2020: -300k

2019: -420k

2018: +370k

2017: +220k

2016: -100k

2015: +180k

2014: +360k

2013: +190k

2012: -480k

2011: +60k

2010: +150k

2009: +490k

2008: +610k

2007: -170k

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On 5/26/2023 at 10:10 AM, bluewave said:

Based on these cooler May temperatures across the Arctic, the melt pond season is probably getting off to a slower start. This is what the melt pond model uses to project a September minimum when the data is released in June by Will Gregory CPOM. So this could mean that the 2012 record will be safe for another year. It’s the opposite of the May record warmth which lead to the big melt year in 2020.

 

6793FCD2-428F-4E0E-8694-9D423765A972.gif.b70196672427a6642901b4724370c670.gif
DBC17DA2-11B3-4EF9-A707-E3B7F2FFC244.png.19e8d3cc0facfbad9a554a4f6875fa84.png
https://ocean.dmi.dk/arctic/meant80n.uk.php

 

On 6/24/2023 at 9:48 AM, bluewave said:

The model run by Will Gregory at CPOM based on May conditions is going for an average September extent of 4.46 million sq km. This is solidly within the range since 2013. The model has been very accurate. So the 2012 record should be safe for another year 

https://www.arcus.org/files/sio/panarctic/2023_june_sio_cpom_ucl_gregory_et_al.pdf

Executive summary" of your Outlook contribution (using 300 words or less) describe how and why your contribution was formulated. To the extent possible, use non-technical language.
This statistical model computes a forecast of pan-Arctic September sea ice extent . Monthly averaged May sea ice concentration and sea-surface temperature fields between 1979 and 2023 were used to create a climate network (based on the approach of Gregory et al 2020). This was then utilised in a Bayesian Linear Regression in order to forecast September extent. The model predicts a pan-Arctic extent of 4.46 million square kilometres. Sea ice concentration data were taken from NSIDC (Cavalieri et al., 1996; Maslanik and Stroeve,1999) and sea-surface temperature data were taken from ERA5 (Hersbach et al., 2019)

Average September extents since 2012

 

 

2022….4.87

2021……4.92

2020……3.92

2019……4.32

2018…...4.71

2017……4.87

2016……4.72

2015…..4.63

2014…..5.28

2013…..5.35

2012…..3.60

Forecast based on the slower start to the melt season back in May compared to some of the stronger melt years appears to be on track.

 

 

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Update:

On 7/23, NSIDC area was 4.85 million sq km. Here's how other years compared on the same date:

2022: +550k

2021: +210k

2020: -460k

2019: -290k

2018: +180k

2017: +50k

2016: -50k

2015: +150k

2014: +460k

2013: +90k

2012: -340k

2011: -250k

2010: +240k

2009: +560k

2008: +590k

2007: -90k

 

Area loss has been pretty strong so far this month putting us slightly below the 2007-2022 mean. We may be able to sneak into the top 5 if strong losses can continue into August.

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15 hours ago, pazzo83 said:

what in the fuck is going on in Antarctica...

 

This stuff is beyond infuriating. Let me preface my quick rant by saying climate change is undeniably real.

Now- you can see in the data that almost every year produces at least multiple 1-2 sigma events. This means the data is not normally distributed which makes sense because weather is not normally distributed (I.e doesn’t fall in a bell curve). So when that happens you need to normalize your data in order to then analyze it.

what you don’t do is call it good enough and claim we are under going a 6 sigma event. It ruins the credibility of the science of CC not to mention your own. This stuff is scary enough, I don’t know why charlatans have to exaggerate and obfuscate- it’s unreal.

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2 hours ago, Supernovice said:

This stuff is beyond infuriating. Let me preface my quick rant by saying climate change is undeniably real.

Now- you can see in the data that almost every year produces at least multiple 1-2 sigma events. This means the data is not normally distributed which makes sense because weather is not normally distributed (I.e doesn’t fall in a bell curve). So when that happens you need to normalize your data in order to then analyze it.

what you don’t do is call it good enough and claim we are under going a 6 sigma event. It ruins the credibility of the science of CC not to mention your own. This stuff is scary enough, I don’t know why charlatans have to exaggerate and obfuscate- it’s unreal.

show your work in claiming that antarctic sea ice extent isn't normally distributed.  and you can still calculate SD/recurrence probability on non-normal distributions as long as you can construct the PDF.

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55 minutes ago, pazzo83 said:

You're also conflating the raw calculation of std deviation (which is divorced from whether or not the data is normally distributed) vs a recurrence interval (which requires the PDF) - and the latter isn't mentioned in the tweet.

Listen- I don’t want to argue the point to death. That chart is crap- it’s been reposted a million times, not just here, I was going to post about it regardless if anything was on here- it’s not a personal attack on you at all. 

The data is very very concerning but let’s represent it in an accurate format. That’s all I’m saying.

 

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3 hours ago, Supernovice said:

Listen- I don’t want to argue the point to death. That chart is crap- it’s been reposted a million times, not just here, I was going to post about it regardless if anything was on here- it’s not a personal attack on you at all. 

The data is very very concerning but let’s represent it in an accurate format. That’s all I’m saying.

 

I think if you took a period of record prior to the year 2000 and looked at Antarctic sea ice anomalies, you'd find they were approximately normally distributed.  Of course perhaps now they aren't because there is rapid change going on.

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1 hour ago, pazzo83 said:

I think if you took a period of record prior to the year 2000 and looked at Antarctic sea ice anomalies, you'd find they were approximately normally distributed.  Of course perhaps now they aren't because there is rapid change going on.

Yep, and that's the problem. We don't know what the distribution necessarily looks like now and since the transient climate response is so rapid by the time you get enough data, it's already moved on.

Needless to say, paleoclimate doesn't have many nice things to say about where we're headed. This sort of "climate flickering" happened in periods of rapid change in the past as well.

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Several years ago when the ice around Antarctica were at all times highs, and people said global warning is fake, the scholars said it all melts out anyway so the ice doesn't matter.  Now that it's low, all of a sudden it's a problem.  The message they send out doesn't mesh.  

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On 7/24/2023 at 8:51 AM, ORH_wxman said:

Update:

On 7/23, NSIDC area was 4.85 million sq km. Here's how other years compared on the same date:

2022: +550k

2021: +210k

2020: -460k

2019: -290k

2018: +180k

2017: +50k

2016: -50k

2015: +150k

2014: +460k

2013: +90k

2012: -340k

2011: -250k

2010: +240k

2009: +560k

2008: +590k

2007: -90k

 

Area loss has been pretty strong so far this month putting us slightly below the 2007-2022 mean. We may be able to sneak into the top 5 if strong losses can continue into August.

 After a steep average daily area loss late June through the first half of July, the last two weeks overall have had a significantly lower average daily loss. Yesterday (7/29) actually had a gain of 33k sq km (to 4.52 million sq km), the first in quite awhile. Although a summer daily gain isn't common, there usually have been several per summer even during big loss years like 2020, 2019, 2017, 2016, and 2012 per the graphs.

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On 7/25/2023 at 10:24 PM, FPizz said:

Several years ago when the ice around Antarctica were at all times highs, and people said global warning is fake, the scholars said it all melts out anyway so the ice doesn't matter.  Now that it's low, all of a sudden it's a problem.  The message they send out doesn't mesh.  

Citation definitely needed for this statement. Preferably anything peer-reviewed.

Conversely, where are all the deniers from '13-'15 that were crowing about record highs then? Crickets now. That's the kind of behavior that you'd expect from people that have zero conviction about their theory. They vanish or move the goalposts when the short-term data goes against them. 

The constructive interference of internal variablity + wind stress changes + tropical forcing was always going to flip the other way at some point and if you knew what you were talking about, had conviction with the data to back it up and were willing to eat some humble pie in the short run, the prediction was always going to pan out in the longer-term.

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 Regarding Arctic ice area, yesterday had a gain. Whereas having a couple of gains during summer is common, having 3 gains in five days isn't. There has been an average daily loss of only ~50k for the last 12. This is opposite of the June 29th to July 14th period when average daily losses were a much larger ~137k.

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2 hours ago, GaWx said:

 Regarding Arctic ice area, yesterday had a gain. Whereas having a couple of gains during summer is common, having 3 gains in five days isn't. There has been an average daily loss of only ~50k for the last 12. This is opposite of the June 29th to July 14th period when average daily losses were a much larger ~137k.

There’s been almost a hiatus in the last week or so. Not quite like 2013’s 10 day hiatus but definitely a slow down big enough to put 2023 back into the lower melt years post-2007. There’s a good amount of vulnerable ice though in the ESS/Chukchi/Beaufort so my guess is this is still going to be more of a “middle of the pack” type season. I’ve been on vacation the past week but will give a numbers update when I return. 

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On 8/3/2023 at 5:05 PM, ORH_wxman said:

There’s been almost a hiatus in the last week or so. Not quite like 2013’s 10 day hiatus but definitely a slow down big enough to put 2023 back into the lower melt years post-2007. There’s a good amount of vulnerable ice though in the ESS/Chukchi/Beaufort so my guess is this is still going to be more of a “middle of the pack” type season. I’ve been on vacation the past week but will give a numbers update when I return. 

Any update?

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21 hours ago, 40/70 Benchmark said:

Any update?

Melting accelerated a lot since my last post to be closer to the higher melt years, but then slowed down again the last couple days....so we're kind of back in the middle of the pack again...maybe a little below the mean. 

 

On 8/10, NSIDC area was at 3.82 million sq km. Here's where other years were in comparison on the same date:

2022: +430k

2021: +80k

2020: -420k

2019: -400k

2018: +240k

2017: +50k

2016: -160k

2015: -130k

2014: +850k

2013: +510k

2012: -770k

2011: -260k

2010: +370k

2009: +650k

2008: +140k

2007: -170k

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NSIDC area is currently at 3.34 million sq km. This is 110k higher than the to-date min on 8/18 of 3.23 million sq km. It is highly unlikely we've reached the min that early as it would break the record for earliest minimum by 11 days.

There's still a shot we can sneak into a top 5 melt season, but it needs to pick back up soon.

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3 hours ago, ORH_wxman said:

NSIDC area is currently at 3.34 million sq km. This is 110k higher than the to-date min on 8/18 of 3.23 million sq km. It is highly unlikely we've reached the min that early as it would break the record for earliest minimum by 11 days.

There's still a shot we can sneak into a top 5 melt season, but it needs to pick back up soon.

Mm with the sun starting to slope and the AO flipping into the positive mode melt would traditional slow fwiw

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  • 2 weeks later...

NSIDC SIA has seen a strong decline late in August and early September. Now down to 2.78 million sq km. That gets this season into a top 5 year. We need about another 100k to get into top 3 to beat out 2020. We’re running out of vulnerable ice but if we can decline another 2-3 days in a row, then we’ll have a chance. 

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