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Wherestheice

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The ice is much thinner than 2012
« on: July 26, 2018, 04:53:34 AM »
I know this post belongs in the melting season thread, but i could only figure out how to post the image below when making a new thread so here ya go.

The ice is way thinner than 2012 and I think that means trouble ahead.
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oren

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Re: The ice is much thinner than 2012
« Reply #1 on: July 26, 2018, 05:20:48 AM »
This model does not provide good comparisons between years, and I believe is not very useful for determining thickness.
Here's what the much more reliable PIOMAS had to say on June 30th (soon we will have July 31st as well). Thanks to Wipneus for the graphics.
p.s. to add an image as attachment while making a standard post is exactly the same as for a new thread - you click the "+" for attachments and other options, and then click "choose file" to add the image of your choice.

Wherestheice

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Re: The ice is much thinner than 2012
« Reply #2 on: July 26, 2018, 05:37:20 AM »
This model does not provide good comparisons between years, and I believe is not very useful for determining thickness.
Here's what the much more reliable PIOMAS had to say on June 30th (soon we will have July 31st as well). Thanks to Wipneus for the graphics.
p.s. to add an image as attachment while making a standard post is exactly the same as for a new thread - you click the "+" for attachments and other options, and then click "choose file" to add the image of your choice.

Ok thank you Oren
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GoSouthYoungins

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Re: The ice is much thinner than 2012
« Reply #3 on: July 26, 2018, 05:39:31 AM »
Where PIOMAS shows extra ice (vs 2012), worldview can show that their is not.
big time oops

S.Pansa

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Re: The ice is much thinner than 2012
« Reply #4 on: July 26, 2018, 06:53:05 AM »
Where PIOMAS shows extra ice (vs 2012), worldview can show that their is not.
Can it?
Below the WorldView from June 30th. What was below the clouds reveals the concentration map (AMSR2) from UniBremen (same date).
To my aging eyes the differences are small, no?

DavidR

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Re: The ice is much thinner than 2012
« Reply #5 on: July 26, 2018, 08:13:02 AM »
I know this post belongs in the melting season thread, but i could only figure out how to post the image below when making a new thread so here ya go.

The ice is way thinner than 2012 and I think that means trouble ahead.
Assuming you use Windows there is a snipping tool, type snip in search, that will allow you  to  just  capture the area of the screen that is relevant  to your post. Save that  as a png file and you  can then add it as an attachment to  your post providing a much larger and more readable image.
 
(Unfortunately I  could only capture your small image. )
Toto, I've a feeling we're not in Kansas anymore

Wherestheice

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Re: The ice is much thinner than 2012
« Reply #6 on: July 26, 2018, 08:23:12 AM »
I know this post belongs in the melting season thread, but i could only figure out how to post the image below when making a new thread so here ya go.

The ice is way thinner than 2012 and I think that means trouble ahead.
Assuming you use Windows there is a snipping tool, type snip in search, that will allow you  to  just  capture the area of the screen that is relevant  to your post. Save that  as a png file and you  can then add it as an attachment to  your post providing a much larger and more readable image.
 
(Unfortunately I  could only capture your small image. )

The trouble is i use a chromebook, and I know for a fact that has something to do with my posting problems :-\
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johnm33

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Re: The ice is much thinner than 2012
« Reply #7 on: July 26, 2018, 09:44:10 AM »
Whilst I have sympathy for your point I think you're comparing different models

this is from https://www7320.nrlssc.navy.mil/hycomARC/arctic.html
 
this is from https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html

oren

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Re: The ice is much thinner than 2012
« Reply #8 on: July 26, 2018, 09:59:49 AM »
While we're at it, there' s this article about Chromebook shortcuts that explains how to capture a partial screenshot - Ctrl-Shift-F5.
https://www.digitaltrends.com/computing/how-to-take-a-screenshot-on-a-chromebook/

harpy

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Re: The ice is much thinner than 2012
« Reply #9 on: August 02, 2018, 06:51:16 PM »
How are those two models different? 


meddoc

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Re: The ice is much thinner than 2012
« Reply #10 on: August 02, 2018, 06:56:44 PM »
How are those two models different?

2012 is ArC while 2018 is Glb whatever they supposed to mean...
Anyway, Glb can only be traced back til 2014, but shows an overall thinner Pack from then on compared to the older ArC- Models.

However PIOMAS seems to overestimate with regards to Extent (and Volume, too).

magnamentis

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Re: The ice is much thinner than 2012
« Reply #11 on: August 02, 2018, 07:52:43 PM »
i think most of us agree that the ice got a lot thinner over the last 3 years

since the extent and area data are not extremely far off each other at this time of the year
i look forward whether piomas got it right this time or if they still try to tell us something different than lowest on record which IMO it has been most of the time during the last 18 months.

after all volume is nothing else than area x thickness, adding the one dimension to the two others

Steven

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Re: The ice is much thinner than 2012
« Reply #12 on: August 02, 2018, 07:57:30 PM »
There are obvious differences between the "GLB" and "ARC" models, for example in the images below, which are both for the same date (15 July 2017):


 

https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arc_list_arcticictn.html
https://www7320.nrlssc.navy.mil/hycomARC/navo/arc_list_arcticictn.html

Stephan

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Re: The ice is much thinner than 2012
« Reply #13 on: August 02, 2018, 10:23:07 PM »
I made the same observation on that website for a given day. I wonder which of the models is showing a "righter" value. Have the people who run these models gone back to real observations or to buoy measurements of the freeboard of the ice packs? Why has the model changed?
It would be very unwise to take the (old) ARC model with thicker ice and then a later GLB model one or two years later to demonstrate the rapid thinning of the ice (which probably has not taken place, at least not to that extent)

Dharma Rupa

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Re: The ice is much thinner than 2012
« Reply #14 on: August 02, 2018, 11:24:45 PM »
I made the same observation on that website for a given day. I wonder which of the models is showing a "righter" value. Have the people who run these models gone back to real observations or to buoy measurements of the freeboard of the ice packs? Why has the model changed?
It would be very unwise to take the (old) ARC model with thicker ice and then a later GLB model one or two years later to demonstrate the rapid thinning of the ice (which probably has not taken place, at least not to that extent)

We study PIOMAS very carefully, and I think it gets our best rating, and we still don't seem to really believe it.  Therefore, I'd suggest that you not make too many claims based on other models.

magnamentis

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Re: The ice is much thinner than 2012
« Reply #15 on: August 02, 2018, 11:42:53 PM »
I made the same observation on that website for a given day. I wonder which of the models is showing a "righter" value. Have the people who run these models gone back to real observations or to buoy measurements of the freeboard of the ice packs? Why has the model changed?
It would be very unwise to take the (old) ARC model with thicker ice and then a later GLB model one or two years later to demonstrate the rapid thinning of the ice (which probably has not taken place, at least not to that extent)

We study PIOMAS very carefully, and I think it gets our best rating, and we still don't seem to really believe it.  Therefore, I'd suggest that you not make too many claims based on other models.

best does not mean it's correct and then a majority does not make things right either.

the opposite is the case, if the entire pack howls with the wolfs i start to be suspicious, especially when there is no major questioning once the naked eye can see that something is not always right.

the next reasoning is consistency but consistency as well is not a good argument to stick to flawed models.

this is not meant to dispute the value of those models, it's meant to vote for the freedom to question models and to try out other models. to deny someone the right to test and discuss other models and to question existing, even the best existing models is kind of censoring at best.

if a model is as good as the majority thinks, what's the problem then, it will be proven and we all know things more certainly after that.

group dynamics has never lead to anything good in the long run, even after short term achievements, sooner or later they failed big time, hence let's talk openly without restrictions, at least as long as questions are asked and exaggerations are avoided.

Dharma Rupa

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Re: The ice is much thinner than 2012
« Reply #16 on: August 03, 2018, 12:07:02 AM »
this is not meant to dispute the value of those models, it's meant to vote for the freedom to question models and to try out other models. to deny someone the right to test and discuss other models and to question existing, even the best existing models is kind of censoring at best.

The models are fine for what they are, but the way people try to use them -- even a bunch of "scientists" -- is not fine.

Making predictions based upon models which have no demonstrated skill is casting bones.

magnamentis

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Re: The ice is much thinner than 2012
« Reply #17 on: August 03, 2018, 12:38:00 AM »
The models are fine for what they are, but the way people try to use them -- even a bunch of "scientists" -- is not fine.

something along that line i think quite often ;)

while i have an idea why this is so, it does not belong here, or perhaps it would belong here but do more damage than good, after all we have to join forces and not get even more lost in petty arguments.

the models neither solve the problems we're facing but they don't cause them either, hence they're not relevant to the process of finding solutions.

last but not least, since they more or less all show the same trends, they serve their purpose.
only thing i wish at times that they would not be so over valued or seen as holy grails ;)
« Last Edit: August 03, 2018, 02:00:10 AM by magnamentis »

muri

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Re: The ice is much thinner than 2012
« Reply #18 on: August 03, 2018, 01:03:38 AM »
Making predictions based upon models which have no demonstrated skill is casting bones.

I agree. We should be able to create models and compare them using all historical data we have. Deviating models from observations should be rethinked or at least recalibrated. If the model is wrong from initialization to current date, can we trust the prediction? Maybe there should be some threshold when a model is so off the mark with data, we should discard it. And not average it in anymore.

oren

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Re: The ice is much thinner than 2012
« Reply #19 on: August 03, 2018, 02:39:18 AM »
i think most of us agree that the ice got a lot thinner over the last 3 years

since the extent and area data are not extremely far off each other at this time of the year
i look forward whether piomas got it right this time or if they still try to tell us something different than lowest on record which IMO it has been most of the time during the last 18 months.

after all volume is nothing else than area x thickness, adding the one dimension to the two others
I do not agree as a a general statement that "the ice got a lot thinner over the last 3 years." This needs evidence. It's true PIOMAS is just a model and has some failings but if you don't trust it then what is your evidence. We have seen weak winter freezing, but then relatively weak spring melting, probably resulting in ice roughly the same thickness as it used to be. Last year finished with a relatively high extent and area despite having very low volume most of the spring. This didn't feel like it had very thin ice during the summer. This year it seems bottom melt did a lot of damage even when the weather seemed unfavorable to melt, but again your general statement needs some evidence rather than just intuition.

Wherestheice

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Re: The ice is much thinner than 2012
« Reply #20 on: August 03, 2018, 03:06:57 AM »
The old ice is going. That in itself should tell a lot about the thickness. The older the ice, the more thick it is. So if old ice is going away then the ice is getting thinner. I agree with oren in the fact that is hasn't got " A lot" thinner but it has been getting thinner the last three years.



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oren

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Re: The ice is much thinner than 2012
« Reply #21 on: August 03, 2018, 03:22:15 AM »
Thanks Whereistheice. This is indeed evidence of the sort I meant.
I did discover something strange that incidentally undermines this evidence. I was wondering about the source of the chart, and did a google image search which traced it to https://twitter.com/blkahn/status/992430636643311617 providing a link to an article https://earther.gizmodo.com/old-arctic-sea-ice-is-virtually-gone-and-thats-bad-1825773154. The strange thing is that the article has a totally different data point for 2018.
Indeed the same twitter user issued a correction 3 days later https://twitter.com/blkahn/status/993604135483269120 showing the updated chart, which shows a long-term trend of thinning but not an extreme change over the last few years.


Wherestheice

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Re: The ice is much thinner than 2012
« Reply #22 on: August 03, 2018, 03:34:32 AM »
Thanks Whereistheice. This is indeed evidence of the sort I meant.
I did discover something strange that incidentally undermines this evidence. I was wondering about the source of the chart, and did a google image search which traced it to https://twitter.com/blkahn/status/992430636643311617 providing a link to an article https://earther.gizmodo.com/old-arctic-sea-ice-is-virtually-gone-and-thats-bad-1825773154. The strange thing is that the article has a totally different data point for 2018.
Indeed the same twitter user issued a correction 3 days later https://twitter.com/blkahn/status/993604135483269120 showing the updated chart, which shows a long-term trend of thinning but not an extreme change over the last few years.



Oh hmmm interesting. None the less that older ice is harder and harder to find as the years go on.

Thanks for the correction
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Rod

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Re: The ice is much thinner than 2012
« Reply #23 on: August 03, 2018, 03:39:23 AM »
Great detective work Oren!   I always enjoy your posts because you have some really good insight.   I think the reason for the change to the chart was because NSIDC messed up on their initial report on the age of the ice. 

I don't have time to go back and research it, but I do remember when they first issued the report this spring Neven spotted an anomaly, and someone else from the forum then contacted NSIDC and they retracted the initial report and issued a revised one.  That is probably why the chart was changed and the article has an incorrect data point.

That said, I agree that we need more evidence about the thickness of the ice.  It seems intuitive that the ice must be thinner.  But, without observational data it is still just guess work. 

Adam Ash

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Re: The ice is much thinner than 2012
« Reply #24 on: August 03, 2018, 06:00:22 AM »
Perhaps, too, the thicker ice these days is produced more via compaction effects (ridging), rather than freezing in depth.  Weaker ice would ridge more readily than the former multi-year ice, I would think.  This would create a semblance of 'thickness' but for a different reason than the intensity of cold would.  ??

magnamentis

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Re: The ice is much thinner than 2012
« Reply #25 on: August 03, 2018, 04:12:11 PM »
i think most of us agree that the ice got a lot thinner over the last 3 years

since the extent and area data are not extremely far off each other at this time of the year
i look forward whether piomas got it right this time or if they still try to tell us something different than lowest on record which IMO it has been most of the time during the last 18 months.

after all volume is nothing else than area x thickness, adding the one dimension to the two others
I do not agree as a a general statement that "the ice got a lot thinner over the last 3 years." This needs evidence. It's true PIOMAS is just a model and has some failings but if you don't trust it then what is your evidence. We have seen weak winter freezing, but then relatively weak spring melting, probably resulting in ice roughly the same thickness as it used to be. Last year finished with a relatively high extent and area despite having very low volume most of the spring. This didn't feel like it had very thin ice during the summer. This year it seems bottom melt did a lot of damage even when the weather seemed unfavorable to melt, but again your general statement needs some evidence rather than just intuition.

i'm surprised that you don't agree to that the ice got thinner in general but it's good to know
that this is not mutually agreed upon, will raise my tolerance level towards certain posts ;)

thanks because to me it matters who and how and i like your how especially well :-)


gerontocrat

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Re: The ice is much thinner than 2012
« Reply #26 on: August 03, 2018, 07:52:38 PM »
Average thickness = Volume divided by (Area or Extent).

So attached is a crude calculation using monthly averages from the Polar Science Center (POIMAS volume)and NSIDC extent and area) from 1979 to now (end June 2018).

It says in 2012 the ice was thinner.

EDIT added the full size garph - click to see it properly
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magnamentis

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Re: The ice is much thinner than 2012
« Reply #27 on: August 03, 2018, 10:13:23 PM »
Average thickness = Volume divided by (Area or Extent).

So attached is a crude calculation using monthly averages from the Polar Science Center (POIMAS volume)and NSIDC extent and area) from 1979 to now (end June 2018).

It says in 2012 the ice was thinner.

EDIT added the full size garph - click to see it properly

but in fact it wasn't. the reminder of the pack was 1-2 meters thicker than now and the area coverd with such thick multi-year ice was much larger.

if i doubt the volume calculation you can't proof the accuracy of that doubted results by using that exact result in volume calculation as one of 3 factors or dividers ;) it's a kind of paradoxon to do so.

i say that volume calculation is flawed without questioning it's usability due to the consistency, hence a consistent flaw included while i think that the state of the ice has probably increased that flaw's impact on the outcome.

i can't really understand why some are so reluctant to verify the numbers as good as we can.

if i see a chart or a map with 2m thick ice where the satellites show open water or fractured floes i have real difficulties to take those for granted, on the opposite, i'm rater sure something is not right.

again without questioning the value of those calculations as mentioned above.

nevertheless there would as well be nothing wrong to develop a better tool and if it's only to be used parallely for a while. one to build history and the other to be a step closer to the real thing.

to make sure that there is no misunderstanding, i find the discussion intersting but until now none of the reasoning convinced me. most of the reasoning included a kind of self-verification of the tools in question by those tools themselves and that's not a convincing approach. neither is the long period of using those algorithms or the fact that they're used by a majority, mostly due to a lack of better ones in any way a proof. common sense or mutual understanding are both nice but no proof.

i could now provide a huge list from history where everyone with few exceptions shared a view or opinion and still they were totally wrong.
« Last Edit: August 03, 2018, 10:22:01 PM by magnamentis »

binntho

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Re: The ice is much thinner than 2012
« Reply #28 on: August 04, 2018, 08:29:37 AM »
Average thickness = Volume divided by (Area or Extent).

So attached is a crude calculation using monthly averages from the Polar Science Center (POIMAS volume)and NSIDC extent and area) from 1979 to now (end June 2018).

It says in 2012 the ice was thinner.

EDIT added the full size garph - click to see it properly

but in fact it wasn't. the reminder of the pack was 1-2 meters thicker than now and the area coverd with such thick multi-year ice was much larger.


Late night typing? Less verbiage and fewer spelling mistakes would perhaps help.

I've no idea what you are trying to say magnamentis, but I've seen nothing to indicate that the ice is much thinner now than it was in 2012. Rather, the average thickness seems to have stayed fairly constant for the last 6 years, perhaps even going up a bit.

Nasa made a very nice video showing the changes between FIY and MIY since 1986 (the video ends 2016) and it certainly seems that MIY was at its lowest level in 2012, and has increased slightly since then.

magnamentis

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Re: The ice is much thinner than 2012
« Reply #29 on: August 04, 2018, 06:16:30 PM »
Average thickness = Volume divided by (Area or Extent).

So attached is a crude calculation using monthly averages from the Polar Science Center (POIMAS volume)and NSIDC extent and area) from 1979 to now (end June 2018).

It says in 2012 the ice was thinner.

EDIT added the full size garph - click to see it properly

but in fact it wasn't. the reminder of the pack was 1-2 meters thicker than now and the area coverd with such thick multi-year ice was much larger.


Late night typing? Less verbiage and fewer spelling mistakes would perhaps help.

I've no idea what you are trying to say magnamentis, but I've seen nothing to indicate that the ice is much thinner now than it was in 2012. Rather, the average thickness seems to have stayed fairly constant for the last 6 years, perhaps even going up a bit.

Nasa made a very nice video showing the changes between FIY and MIY since 1986 (the video ends 2016) and it certainly seems that MIY was at its lowest level in 2012, and has increased slightly since then.

while i accept your differing opinion without agreeing i propose that we continue in my language and see how many mistakes you make.

i think that using typos and language barriers as reasoning is not helpful. for a non-native english speaker and non-translator or anything of that kind my english is usually good enough while it will never reach the level of those who have learned english from childhood or studied it.

as i speak 6 languages i just don't have the time to bring the 5 that or not my native ones to top level and ask you to forgive me the typo's, i've simply many more things to learn and to do than to perfect something that is in 99% of all cases good enough to communicate properly.

as to your reasoning:

a) first of all not much thinner does not exclude thinner as such

b) 2012 would be the only year that perhaps is close to this year but as piomas sees this year
.  5th lowest  i say (my opinion, no need to agree) that this is not correct.

.  i remember times when we had large areas of 3-5 meter thick ice north of CAA as well as
.  large areas which are now 1-2 meters less and much smaller of MYI in the beaufort which is
.  now gone or in the process to vanish while i don't see any new regions with that kind of
.  thickness where before the ice was thin or melted out at his time of the year.

unfortunately i don't like much to come back later to say "you see" but the day will come.

there have been many enough opportunities where there was shown thick ice and in fact there was open water and/or slush ice and that's proof enough that those data are not holding scrutiny.

i think that extent is one of the factors in that algorithm and extent is currently a very poor
indicator for sea-ice conditions while it has once been good. that was at times when there was either no ice as opposed to more or less solid ice cover, means there were clean edges. things have changed and many decades old algorithms don't cope with those changes.

i'm gladly waiting another few years until this will become mutually agreed upon.

i hope i was able to make myself understood despite the poor language while i don't usually have much issues with my english except that it's clearly not perfect.

last but not least it's not really indicative to not understand what someone is trying to say, it does not say anything about whether what he/she is trying to say is right or wrong or just something to consider. most often it means something else but won't go there to keep it civil.
« Last Edit: August 04, 2018, 06:27:05 PM by magnamentis »

Steven

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Re: The ice is much thinner than 2012
« Reply #30 on: August 04, 2018, 08:04:06 PM »
I think the reason for the change to the chart was because NSIDC messed up on their initial report on the age of the ice. 

I don't have time to go back and research it, but I do remember when they first issued the report this spring Neven spotted an anomaly, and someone else from the forum then contacted NSIDC and they retracted the initial report and issued a revised one. 

It was diablobanquisa who found the source of the problem with that ice age map:
https://forum.arctic-sea-ice.net/index.php/topic,2278.msg152906.html#msg152906



I've seen nothing to indicate that the ice is much thinner now than it was in 2012.

I agree.  Both PIOMAS and CryoSat suggest that the sea ice in spring 2018 was thicker than in 2012:



Since the 2018 melt season is not as strong as in 2012, I think it's plausible that this conclusion is still valid: so the ice at this moment is probably thicker than in 2012.

binntho

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Re: The ice is much thinner than 2012
« Reply #31 on: August 05, 2018, 09:48:24 AM »
while i accept your differing opinion without agreeing i propose that we continue in my language and see how many mistakes you make.

i think that using typos and language barriers as reasoning is not helpful. for a non-native english speaker and non-translator or anything of that kind my english is usually good enough while it will never reach the level of those who have learned english from childhood or studied it.

as i speak 6 languages i just don't have the time to bring the 5 that or not my native ones to top level and ask you to forgive me the typo's, i've simply many more things to learn and to do than to perfect something that is in 99% of all cases good enough to communicate properly.

Well we do seem to have some things in common! I'm not a native English speaker and speak "only" three languages fluently, although I'm able to get by in another couple of languages.

a) first of all not much thinner does not exclude thinner as such

b) 2012 would be the only year that perhaps is close to this year but as piomas sees this year
.  5th lowest  i say (my opinion, no need to agree) that this is not correct.


But isn't your claim that the ice is "much thinner than 2012"? There is no evidence to show this, on the contrary: All evidence points to thicker ice, more volume and more MYI this year than 2012. It doesn't matter how many words you write, if you make a claim, show some evidence!

magnamentis

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Re: The ice is much thinner than 2012
« Reply #32 on: August 05, 2018, 04:41:57 PM »
a) first of all not much thinner does not exclude thinner as such

b) 2012 would be the only year that perhaps is close to this year but as piomas sees this year
.  5th lowest  i say (my opinion, no need to agree) that this is not correct.

But isn't your claim that the ice is "much thinner than 2012"? There is no evidence to show this, on the contrary: All evidence points to thicker ice, more volume and more MYI this year than 2012. It doesn't matter how many words you write, if you make a claim, show some evidence!

ok, here you have a point, i shall amend that:
and i'm happy about it because any found flaw is beneficial for everyone, i can correct the mistake and at the same time try to elaborate which is good "per se" ;)

the word "much" thinner may be a an exaggeration based on an impression and/or a minor abuse of the word, intent to emphasize my point, a bit over exited perhaps, so to say ;)

what many use as evidence, i.e. "all data point at" are the sources which i question, hence as mentioned earier and elsewhere, to use a doubted source as evidence/proof to make the very same source look accurate/correct, is not what i look at as proper reasoning.

i use other sources to build my point/opinion such as:

- most of the 5m thick ice gone = a lot of volume gone since thickness is a key factor of volume

- almost year round above average temps and similar extents (small differences) let's me ask, when and where should all that supposedly thicker ice have been built? and since the last 2 winters were similarly warm even more so.

- i take the lowest extent in 2012 and the thickness of the remaining ice as a starting point all the ice from there onward was one or two year ice, none of them survived the 3 year after that ( ice drift has to be considered here, the ice over the pole in 2012 is now mostly gone, exported and melted.)

- since there is no reason to believe that during warm winters with ever less maximum extent, hence more humid air masses and closing in waterfronts, ice could have significantly grown in thickness as compared to earlier years.

- i think a lot of that thickness is snow of which due to raised humidity is probably more and i can't see how to reliably distinguish ice from snow form the air. it's one of the several changes in conditions that the algorithms currently don't cope with because they're from times when conditions were different and much easier to calculate.

- even extent/area that are probably part of the calculations are currently not reliable, hence we have questionable thickness and questionable two-dimensional data which all together leave a lot of room for doubts and questioning.

again, my proposal for quite some time is that:

- we gather more date (buoys, measurements etc.)

- we adapt the algorithms to the new conditions over which is little dispute

- we use the new and the old datasets parallely as long needed, until we made the transition form short-term to longterm and perhaps even find a way to "bridge" the two datasets or recalculate the old ones with the new algorithms and letting the newly found revelations flow into them.

these are specific and clear proposals which if they're useless or wrong have to be explained and if they're not that bad ideas should be taken on.
« Last Edit: August 05, 2018, 04:56:10 PM by magnamentis »

binntho

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Re: The ice is much thinner than 2012
« Reply #33 on: August 05, 2018, 05:14:27 PM »
Well, yes, a slight exaggeration to claim that ice is much thinner when in fact it is thicker.

I wonder if all the clever scientists working on the various models (with regular input from direct measurements) have ever considered all the things you listed above, which you seem to think invalidates all their work.

Claims need evidence, and if I claim that the ice is thicker then I can easily find the evidence. Is it perfect evidence? No, I think it may well be flawed in various ways, but it is the only evidence we have! There is certainly no evidence of the ice being thinner now than in 2012 despite your musings.

In fact it seems that some sort of plateau was reached early this decade, and since then, at the start of the melting season each year, FYI has been fairly constant at just under 70%, second year ice at c.a. 15%, third year ice just between 5 and 10% and fourth and fifth year ice at very similar levels, c.a. 5% each (all from eye-balling NSIDC charts)

magnamentis

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Re: The ice is much thinner than 2012
« Reply #34 on: August 05, 2018, 06:31:15 PM »
Well, yes, a slight exaggeration to claim that ice is much thinner when in fact it is thicker.

I wonder if all the clever scientists working on the various models (with regular input from direct measurements) have ever considered all the things you listed above, which you seem to think invalidates all their work.

Claims need evidence, and if I claim that the ice is thicker then I can easily find the evidence. Is it perfect evidence? No, I think it may well be flawed in various ways, but it is the only evidence we have! There is certainly no evidence of the ice being thinner now than in 2012 despite your musings.

In fact it seems that some sort of plateau was reached early this decade, and since then, at the start of the melting season each year, FYI has been fairly constant at just under 70%, second year ice at c.a. 15%, third year ice just between 5 and 10% and fourth and fifth year ice at very similar levels, c.a. 5% each (all from eye-balling NSIDC charts)

those are claims as well no evidence. we can gladly exchange claims and reason by finding flaws in the other's reasoning which is what i try but you come back trying to proof my reasoning wrong with the data i question, so much about repetition ;)

invalidates ALL their work

is the same kind of exaggeration, not ALL but some, yes and it's neither their fault, there are many factors like funding and internal competition and ranking etc.

and you did it again, due to lack of arguments in direct reply to mine, you try to draw "public accord" to your side by laying words into one's mouth that one neither meant nor said, following the aforementioned path to discredit or build momentum of antipathy against what can't be opposed with own means, quasi with the help of "IMAGE MANIPULATION" one of the eight weapons of the con-artists, often and gladly adapted by their victims.

as a result and since it's already done, i can as well do it myself then LOL

to be a scientist for me is not evidence for smartness and certainly not for wisdom, but only for a specific and a certain level of education that can be acquired with hard work as well as with smartness or a combination of both.

on the contrary, many scientist have a very limited mind, limited and focused on their field of work which at time leads to catastrophic "solutions" and results of course, if only they're sufficiently connected and/or ruthless. and to not let you do it again, i don't say all are like this but some.
if it were appropriate i'd gladly post an excerpt of my unfinished book about "cheating correctness"

so as long as some believe that a title prevails over facts, logics and reason and as long as
reputation is rated higher than wisdom we shall continue on the path to self-destruction.

after all, this is exactly on of the key reasons why despite the fact that we are aware of most problems long before the shit hits the fan, nothing happens. because those higher up don't want to loose their benefits and they often abuse scientist to get their way, after all most scientists are government paid employees and that shows. of course this is another one of those statements that won't make me friends but i couldn't care less, as long as ai can a name things and i never say it's all, but many, too many IMO.

global warming was discussed 60 years ago during my school time, hence it was out in the public already then, and now see where we are, it's gotten worse ever since.

i could tell you thousands of examples where common sense and looking at the big picture prevailed over limited expert skills.

easiest wold be that at times i fixed an engine that didn't work correctly within 5 minutes and the help of one simple tool while the 3 mechanics were searching with computers and stuff for 2 hours until i lost patience and took that number 10 tool and tightened those 3 screws which i told them for 2 hours must be loose LOL

i know, examples always limp but not when there are hundreds and thousands of example with similar outcomes, sooner or later one has to admit there is a pattern and start to believe it.

binntho

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Re: The ice is much thinner than 2012
« Reply #35 on: August 05, 2018, 07:22:02 PM »
those are claims as well no evidence. we can gladly exchange claims and reason by finding flaws in the other's reasoning which is what i try but you come back trying to proof my reasoning wrong with the data i question, so much about repetition ;)

I'm not sure what sort of evidence you would ask for. There are several major scientific operations that produce thickness data. We know that it's not perfect data, but it is hell of a lot better than writing long lists about what you think things should be.

Graphs can easily be found all over this forum if you want to check them, but I thought I might just go over your points one by one from an earlier post:

- most of the 5m thick ice gone = a lot of volume gone since thickness is a key factor of volume

Looking at the Polar Portal map for today and same date 2012 shows that there is no 5m ice either year. Actually, in 2012 there was hardly any ice thicker than 3.5 meters on this date, while this year there are small areas of 4m thick ice, and the ice is thicker generally than on the same date 2012.

- almost year round above average temps and similar extents (small differences) let's me ask, when and where should all that supposedly thicker ice have been built? and since the last 2 winters were similarly warm even more so.

A fair point. Yes, winter temperatures have been going up these last few years and many expected volume to fall because of this. And sure enough, winter volume has been falling these last few years, and was especially low last year. But again looking on Polar Portal, the main difference seems to be in winter extent, which is also significantly lower this year than 2012.

So with less volume, but also less extent, the thickness this winter was more than in 2012 as can be seen on Neven's thickness graph.

Although I'm no expert, I seem to remember a discussion on how ice forms, and why the warmer winter temperatures wont have any major effect on ice thickness. Essentially, it's bloody cold up there, and once freezing starts, thickness grows very quickly to begin with. The last few tens of centimeters take a lot longer, and it's there that slightly warmer temperatures might have an effect.

- i take the lowest extent in 2012 and the thickness of the remaining ice as a starting point all the ice from there onward was one or two year ice, none of them survived the 3 year after that ( ice drift has to be considered here, the ice over the pole in 2012 is now mostly gone, exported and melted.)

No, this is not valid. At the 2012 minimum there was quite a bit of second, third, fourth year and older ice still remaining. Yes, all the ice that formed in 2012 is presumably gone by now, but that is neither here nor there.

- since there is no reason to believe that during warm winters with ever less maximum extent, hence more humid air masses and closing in waterfronts, ice could have significantly grown in thickness as compared to earlier years.

Well, again this doesn't really hold. The "significant" part of ice thickness growth happens quickly, and even if the temperatures are not quite as cold as usual, they are easily cold enough to get the first, significant, bit of thickness in place. And starting a sentence with "no reason to believe" is not promising for what follows. It essentially means "I believe it, but I don't have any evidence".

- i think a lot of that thickness is snow of which due to raised humidity is probably more and i can't see how to reliably distinguish ice from snow form the air. it's one of the several changes in conditions that the algorithms currently don't cope with because they're from times when conditions were different and much easier to calculate.

Yes, others have also talked about the possibility that snow is fooling the sensors. And I'm sure they are. It does seem to snow more in the northern regions now than it used to. But there are very few direct measurements. A-Team has written extensively about this and what evidence there is seems to show not more than ankle-deep snow on average if I remember correctly.

The arctic ocean itself doesn't receive that much snowfall, it's mostly dry. And if snow does arrive, it would usually come up the North-Atlantic, hitting Svalbard before moving in over the ice. We do have direct measurement of snowfall at Longyearbyen in Svalbard, and this last winter the maximum snow depth was 12 cm.

So, yes, it does snow, and snow does disturb the models and satellite measurements, but it doesn't really seem to be in any significant amounts.

- even extent/area that are probably part of the calculations are currently not reliable, hence we have questionable thickness and questionable two-dimensional data which all together leave a lot of room for doubts and questioning.

Well, I'm not sure how to answer that. Extent and area are measured directly all year round, how can they not be reliable?

Steven

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Re: The ice is much thinner than 2012
« Reply #36 on: August 05, 2018, 08:46:28 PM »
A-Team has written extensively about this and what evidence there is seems to show not more than ankle-deep snow on average if I remember correctly.

Ankle-deep is an underestimation, unless you're a giraffe :-).  See for example this 2018 paper:

Reconstruction of Snow on Arctic Sea Ice

From Figures 1 and 12 in that paper, the reconstructed snow depth for April in previous years:



For April 2018, I plotted the image below using the IceBridge preliminary data:
https://forum.arctic-sea-ice.net/index.php/topic,2282.msg161244.html#msg161244
« Last Edit: August 05, 2018, 09:11:27 PM by Steven »

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Re: The ice is much thinner than 2012
« Reply #37 on: August 05, 2018, 09:21:37 PM »
There's a lot of snow on the ice when PIOMAS and CryoSat-2 data start to diverge, like they did in the 2012/2013 and 2016/2017 winter seasons. I've written about that quite extensively.

And if you don't consider a combination of PIOMAS, CryoSat-2, Operation Ice Bridge, evidence, you're out there in lala-land where everything goes, no matter how long your comments are.
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binntho

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Re: The ice is much thinner than 2012
« Reply #38 on: August 05, 2018, 09:30:14 PM »
A-Team has written extensively about this and what evidence there is seems to show not more than ankle-deep snow on average if I remember correctly.

Ankle-deep is an underestimation, unless you're a giraffe :-).  See for example this 2018 paper:


Yes, well, I never said which species of mammal ... but that paper is very interesting, the question of how much (or how little) snow falls in the Arctic is perennial. Nevertheless I was surprised that max snow depth this winter in Longyearbyen was only 12 cm. Given that the precipitation comes in from the south, and that Svalbard is there on the southern margin of the ice, one would be tempted to think that snow on the ice itself would always be less than what falls there.

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Re: The ice is much thinner than 2012
« Reply #39 on: August 05, 2018, 11:07:50 PM »
I was surprised that max snow depth this winter in Longyearbyen was only 12 cm.

It's only a single location, but apparently there were several days with above-freezing temperatures in Longyearbyen in January and February, on which the snow depth there decreased:

https://www.yr.no/place/Norway/Svalbard/Longyearbyen/statistics.html

Anyway, the Operation IceBridge data for spring 2018 also suggest that snow depth near Svalbard was relatively low this year, compared to previous years.  But overall, the snow depth on the Arctic sea ice in spring 2018 seems to be more or less in the same ballpack as in previous years.