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Killian

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Re: The 2019 melting season
« Reply #4650 on: July 26, 2019, 12:51:36 PM »
Well, JAXA is back after a day of making me crazy and really screwing up my chance at predicting the overtaking of the 2012 low as the record low crown slipped from 2011 to 2012 on the 25th. I had been pointing at that date for weeks. Grrr!

Anywho, the 24th and 25th:
7/24/2011 stood at 6.68M km sq. on this date.
7/23/2019 stands at 6.67M km sq., needing < +15k (non-rounded) increase for a record low on the 24th.

7/25/2012 stood at 6.62M km sq. on this date.
7/24/2019 stood at 6.62M km sq., a tie for the record, after a drop of 50k km sq. 2019 needed a drop of > 0k km sq. for a record low.

7/25/2012 stood at 6.62M km sq. on this date.
7/25/2019 stands at 6.51M km sq. after a drop of 110k km sq.

This is a record for this date and marks 2019 as currently more deadly for ASIE than 2012 even after the Great Arctic Cyclone event. Now, the long-term effects of the cyclone likely are revealed in the wide, flat bottom of the melt season curve that 2012 anomalously displays, so it's going to take more than just being 110k ahead of 2012 for one day; 2012 lost a lot of ice from the 26th to the 10th. The 110k lead will certainly help to keep 2019 in front for a day or two, at least, if not longer.

7/26/2012 stood at 6.51M km sq. on this date, a drop of 110k.
7/25/2019 stands at 6.51M km sq. 2019 needs a drop > 0k km sq. for a record low on this date.

These are rounded numbers so there's up to 5k difference in those numbers, so anything over -5k should do it for another record day. But, what should we expect? A few days ago the 25th looked pretty mixed, but excuse me as I go read all you good people's comments, check out some graphs and futz around... brb.

I'm baaack! Well, the upper level winds via NullSchool show a dipole, but it is not as prominent using surface winds. The ice must be moved by surface rather than high level winds, while the high level bring the heat, if any... yes? There's strong winds pushing toward the Atlantic between Svalbard and the west Siberian coast which should add to extent, but most winds elsewhere should reduce extent. Serious heat on the Pacific side.

Looks like a recipe for an extant drop of 80 to 110. 95k, then.

Or something.

2012 lost 250k km sq of ASIE over the 26th and 27th, but '19 has 110k to play with, so needs only around 70k/day to keep at a record level and the dipole systems seem harder on the ice after the 26th, so I suspect something like 100k~120 average over these two days with the 26th smaller than the 27th, maybe 95k/120k.

Final for 27th tomorrow.
-------------------------

8/10/2012 stood at 4.94M km sq. on this date.
2019 needs an average daily drop of > 98.13k km sq. for a record low on this post-GAC date. (16 days)

It doesn't look like that French heat is going to get up into the Arctic Ocean as much as some think, at least according to Null. That said, all the systems running around now and the expected sunlit high after might do a number on the ice. Right now I call this a 50/50 chance of 2019 breaking the record on that date.

9/15/2012 stood at 3.18M km sq. on this date.
2019 needs an average daily drop of > 64.04k km sq. for a record low on this date. (52 days)

Who knows? This seems an easier target than the 10th, actually, but I really don't know how slow losses get in late August and Sept.

Better go look.

Rich

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Re: The 2019 melting season
« Reply #4651 on: July 26, 2019, 01:01:22 PM »

PIOMAS volume divided by NSIDC sea ice area seems the only logical way to do it without physical observations, and here it is.....

Note that it seems to have lost 1 metre of thickness since the 2000's, but at mid-July was at 2.4 metres.   Usually what happens now is that scorn is placed upon the data for being awkward.

Thank you Gerontocrat. If anyone wants to know the source of the 2+ meter average thickness for the CAB at 7/15, that's it.

When Neven reports thickness, I believe that's where he gets it. So I'll take cover beyond the PIOMAS / NSIDC combination here for now.

To Oren's point, that is an average. Some is thicker and some is thinner. Clearly, we are going to lose some more CAB area this season. Are we going to lose 1/3 of what's left (what's needed to approach an area minimum) ? I think that is unlikely, but possible. I don't know how crazy the weather will get.

F. Tinioli - I see your Hycom chart. No idea how to reconcile that to PIOMAS. I know the Hamburg chart has been criticized as yielding invalid data in the summer, perhaps Hycom is same boat ?

Binntho - Shame on you for suggesting I disparaged Wipneus' in any way. If he wants to model a different CAB than the conventional one, that's fine with me. I have certainly devoted energy here promoting an alternative perspective of the CAB myself.

I like my popcorn plain. No butter, no salt. Anyone else?

binntho

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Re: The 2019 melting season
« Reply #4652 on: July 26, 2019, 01:07:15 PM »

PIOMAS volume divided by NSIDC sea ice area seems the only logical way to do it without physical observations, and here it is.....

Note that it seems to have lost 1 metre of thickness since the 2000's, but at mid-July was at 2.4 metres.   Usually what happens now is that scorn is placed upon the data for being awkward.

Thank you Gerontocrat. If anyone wants to know the source of the 2+ meter average thickness for the CAB at 7/15, that's it.
No it isn't. You just grabbed a number out of your hat, and then gave totally spurious reasons for where you got it from, citing numbers that were obviously not correct.

Since Gerantocrats graph was obviously not your source, you've added lies to hatgrabbing! Shame.
Quote
Binntho - Shame on you for suggesting I disparaged Wipneus' in any way. If he wants to model a different CAB than the conventional one, that's fine with me. I have certainly devoted energy here promoting an alternative perspective of the CAB myself.
And yet you do it again, and double so, by taling about "conventional" and how you are working hard to find something even better than that (huh!).
because a thing is eloquently expressed it should not be taken to be as necessarily true
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DrTskoul

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Re: The 2019 melting season
« Reply #4653 on: July 26, 2019, 01:21:01 PM »
Enough with the banter back and forth... How tiring... who cares ...accept the damn data showing a large range 1.5 - 2.5 on average and get on with it!!!  Like seeing my kids arguing about the amount of Takis shared between them.

gerontocrat

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Re: The 2019 melting season
« Reply #4654 on: July 26, 2019, 01:21:33 PM »
... Usually what happens now is that scorn is placed upon the data for being awkward.
Well, let's do something else for a change then, eh? From very previous page of this topic, here's what tells much different story (unless, of course, you'd be color-blind):

Now who would be the brave soul to claim that on this one, "blue" and "purple / pinkish" colors all mean 2m+ thickness? Rich, wanna volunteer? I love a good laugh. :D

Not sure I believe that figure  ???, its almost implying the rotten ice in southern Hudson has the same thickness as 50% of the CAB ice
Actually, there may still be some lumps of thickish ice wandering around the Hudson. Lat year was a good year for ice formation in the Hudson. Also has very  low salinity so ice forms earlier and slower to melt.

But as Oren pointed out, average ice thickness of the CAB - a sea of 3.2 million km2 area, is not a lot of help in predicting the final result.  Yet another reason to have wished the CAB had been split up into regions of different vulnerability to melt. But it wasn't.

And if anyone wants to complain about or challenge the PIOMAS or NSIDC data, go take it up with the Polar Science Center or NSIDC and tell us what they say.

Or put up your own satellite - one is desperately needed anyway.
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SimonF92

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Re: The 2019 melting season
« Reply #4655 on: July 26, 2019, 01:24:12 PM »
Haven't been coming on here almost daily for the last 5 years to read arguments, yet arguments seem to almost be an inherent part of the forum
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be cause

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Re: The 2019 melting season
« Reply #4656 on: July 26, 2019, 01:26:50 PM »
Well the edge of the Beaufort ice is melting rapidly. Lots of area of slush simply vanished in 24 hours: https://go.nasa.gov/2K4kowV

 thanx grixm .. that comparison mode is now securely bookmarked ... b.c.

 
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 + 1 =  ' if only we could have seen it coming ' ...

Rich

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Re: The 2019 melting season
« Reply #4657 on: July 26, 2019, 01:42:10 PM »

No it isn't. You just grabbed a number out of your hat, and then gave totally spurious reasons for where you got it from, citing numbers that were obviously not correct.

Since Gerantocrats graph was obviously not your source, you've added lies to hatgrabbing! Shame!

Poor poor Binntho. A smart guy who seems to have swallowed a load of kryptonite.

If you go way back to post 4618, I explained where I got the data supporting the 2+ meters. That is the same data Gerontocrat used to prepare his chart.

It's very uncool to call someone a liar. It should be embarrassing when they can produce a trail demonstrating that they aren't.

Sorry to all that that this has devolved. I can't easily allow someone to accuse me of lying and acquiesce in silence. Not sure how to explain Binntho's temporary insanity.

petm

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Re: The 2019 melting season
« Reply #4658 on: July 26, 2019, 01:52:20 PM »
Enough with the banter back and forth.

+1

Gray-Wolf

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Re: The 2019 melting season
« Reply #4659 on: July 26, 2019, 01:58:31 PM »
Guys,guys!

We know why Neven is away and you want him to come back to this???

Take a chill pill, kiss and make up .and lets move on please?
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VeganPeaceForAll

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Re: The 2019 melting season
« Reply #4660 on: July 26, 2019, 02:11:37 PM »
I think the Hycom sea ice thickness pictures above accurately describes sea ice thickness in areas like Beaufort, ESS, north of Greenland, judging by others' observations/NASA worldview-pictures, etc. posted here the last month.

Looking at the image attached below the ice thickness has been reduced around 1m on average the last 30 days. If this average melt rate continues for one more month, there will not be much ice volume left for the last subsequent period of ice melt.

uniquorn

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Re: The 2019 melting season
« Reply #4661 on: July 26, 2019, 02:13:00 PM »
Yesterday's worldview aqua modis of northern CAA and greenland with medium contrast to highlight fractures and larger floes. The last very large floe north of ellef ringnes has fractured into ~15 smaller floes. As mentioned upthread, large parts of the parry channel are no longer fast ice and there is significant open water around the lincoln sea coast.
click image for detail.  edit: added link  https://go.nasa.gov/2yfFm6u
image name should say jul25
« Last Edit: July 26, 2019, 02:33:09 PM by uniquorn »

F.Tnioli

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Re: The 2019 melting season
« Reply #4662 on: July 26, 2019, 02:30:07 PM »
... Usually what happens now is that scorn is placed upon the data for being awkward.
...
Now who would be the brave soul to claim that on this one, "blue" and "purple / pinkish" colors all mean 2m+ thickness? Rich, wanna volunteer? I love a good laugh. :D
Not sure I believe that figure  ???, its almost implying the rotten ice in southern Hudson has the same thickness as 50% of the CAB ice
Nope, Simon, you can't say that! See, per implied gentlemen's agreement with gerontocrat, we do NOT place any scorn on data for being awkward, this time!

I mean, if he wishes no scorn to be put on data he presented, then none should be placed on data that contradicts his data, too. Means, we just gotta sit and stare and meditate on two sets of data at least one of which is clearly wrong. I don't mind, myself. Meditation is useful! :)
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

F.Tnioli

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Re: The 2019 melting season
« Reply #4663 on: July 26, 2019, 02:37:49 PM »
Guys,guys!

We know why Neven is away and you want him to come back to this???

Take a chill pill, kiss and make up .and lets move on please?
Yep, i concur with Gray-Wolf 100%. Everyone just calm down for Neven's sake, please!

P.S. If someone missed what it's about - it's extraordinary circumstances currently, for Neven: he's enduring through much stressful, very obligating and major family matter, at this time. This is what keeps him away and very busy, for now. Lots on his shoulders now, as it is - and we can help by at very least staying civilized in the forum here.
« Last Edit: July 26, 2019, 02:47:23 PM by F.Tnioli »
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

Shared Humanity

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Re: The 2019 melting season
« Reply #4664 on: July 26, 2019, 02:40:20 PM »
Enough with the banter back and forth... How tiring... who cares ...accept the damn data showing a large range 1.5 - 2.5 on average and get on with it!!!  Like seeing my kids arguing about the amount of Takis shared between them.

Thank you...always the same cast of characters too.

Shared Humanity

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Re: The 2019 melting season
« Reply #4665 on: July 26, 2019, 02:44:25 PM »


I mean, if he wishes no scorn to be put on data he presented, then none should be placed on data that contradicts his data, too. Means, we just gotta sit and stare and meditate on two sets of data at least one of which is clearly wrong. I don't mind, myself. Meditation is useful! :)

Likely that both are.

F.Tnioli

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Re: The 2019 melting season
« Reply #4666 on: July 26, 2019, 02:49:56 PM »
Likely that both are.
Well i wouldn't say "likely" (also, no scorning, remember? :) ) , - but "possible" both are, yes. Which is why i used "at least" in the post you quoted, you see.

But which way? I mean, if you say it's not 2m+ CAB average and not ~1.2...1.4m CAB average, then what is your idea? Somewhere in-between, or <1m? Intresting!
To everyone: before posting in a melting season topic, please be sure to know contents of this moderator's post: https://forum.arctic-sea-ice.net/index.php/topic,3017.msg261893.html#msg261893 . Thanks!

bluice

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Re: The 2019 melting season
« Reply #4667 on: July 26, 2019, 03:11:10 PM »
Looks like polar ice cap is getting completely detached from CAA/Greenland

philopek

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Re: The 2019 melting season
« Reply #4668 on: July 26, 2019, 03:44:49 PM »
Months ago I said if we saw a new minimum the story would be the weather in the mid-latitudes. As all-time records are now falling across Europe, that is clearly the case.

The Greenland situation in sync with the Arctic is severely troubling IMO. I wonder if the rubber band is going to snap in the opposite direction as we head into autumn. With a possible record amount of open water, the Greenland melt, and the rising SSTs, I would think this year is more primed than any before for VERY rapid growth in continental snowfall as the sun falls lower in the sky. This could translate into a severely early and chaotic winter pattern with major snowfalls across most of the mid-latitudes extending into areas that normally do not see them (IMO). I won't get too off-topic, but the end of the melt season is much more likely to coincide with an abnormally early start to winter across the continents, in my opinion.

At the same time, the early onset of snows across North America and Eurasia is likely to advect even MORE oceanic heat into the Arctic in September and October, which could mean we also see a very late minimum this year (to end the post on a note that brings it full circle and totally back on topic). That would also coincide with a very lackluster refreeze, probably worse than 16-17, which could put us in a position where we could see a very horrible minimum in 2020 (like, 1M KM^2 remaining).

That is well withing range to happen, not to say probable. IMO you forget the mention that before that, no matter how brief the period will be, i expect for the very same reasons, either extremely heavy storms, an extremely high succession of strong storms or even both.

As a sailor and windsurfer i'm not totally ignorant when it comes to meteorology but i'd be interested to hear you opinion about the probability of stronger and/or more frequent storms ahead.

Alphabet Hotel

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Re: The 2019 melting season
« Reply #4669 on: July 26, 2019, 03:56:35 PM »
This inlet on the north coast of Greenland is breaking up. The tips of Hendrik I. and Castle I. are visible at the bottom.

Ossifrage

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Re: The 2019 melting season
« Reply #4670 on: July 26, 2019, 04:16:23 PM »
Yesterday's worldview aqua modis of northern CAA and greenland with medium contrast to highlight fractures and larger floes. The last very large floe north of ellef ringnes has fractured into ~15 smaller floes. As mentioned upthread, large parts of the parry channel are no longer fast ice and there is significant open water around the lincoln sea coast.
click image for detail.  edit: added link  https://go.nasa.gov/2yfFm6u
image name should say jul25

I want to dive into this a little further. The M'Clure is terrible. The ~120 km ice arch that had held the line between Banks and Eglinton is no more. There's probably not time for this all to melt; the giant 50 km x 30 km floe in the center of the M'Clure is likely to shatter further, but most of its ice will see the freezing season. On the other hand, the remaining ice in the Prince of Wales Strait is a sickly gray; barring resupply from Viscount Melville Sound, that channel will be ice-free this summer, which will put additional melting stress on the VMS floes.

Further east, the entirety of Massey Sound has cracked apart. There are some four cracks that span the entire channel between Amund Ringness and Axel Heiberg, and a complex crack system north of that that jumps from Ellef Ringnes, across the Perry Channel to Meighen, and across the Sverdrup Channel to Axel Heiberg. It really doesn't matter if this actually melts. The cracking apart of this ice allows for additional motility -- these are channels, after all; they move water and ice. Likewise, the Prince Gustav Adolf Sea remains under cloud so we can't get a measure of the damage there, but it's not likely to be good. Although the PGAS survived 2012 in fairly good form, the Ellef Ringnes side had briefly devolved to open water in 2010.

Why does all this matter? We talk about the garlic press model of the CAA a lot. The idea is that open sea ice is compacted between the QE and Sverdrup Islands and forced into channels where pressure ridging (and the innate resilience of fast or near-fast ice) improves its thickness. Then, slowly, that ice is transported south and east until it reaches a melt zone. This year, that model of the CAA is failing. The Crack has replaced the typical CAA/CAB transition zone; there is negative garlic entering the press. Instead, fast ice continues to be scoured off the northern islands by the relentless torque and shipped to its death in the Beaufort. The two best CAA-internal ice incubators are the PGAS and the Perry/Sverdrup/Massey channel complex, but both of those are breaking up and experiencing increased ice movement. Typical motility is about 1-2% of average ambient wind speed (with the eastern PGAS transport slightly faster apparently due to an undescribed current along the west face of Ellef Ringnes).

These areas don't have to clear for this to be bad news for both the freezing season and next year's melt. They just have to export their ice faster than normal, while cut off from their own resupply. And that's exactly what's happening.

Sarat

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Re: The 2019 melting season
« Reply #4671 on: July 26, 2019, 04:26:22 PM »
Here is GFS 2m temp forecast for Greenland heatwave, as compared to it's usual state (today). Looks like it will be cooking from Jul 30-Aug 1.


gerontocrat

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Re: The 2019 melting season
« Reply #4672 on: July 26, 2019, 05:06:03 PM »
Likely that both are.
Well i wouldn't say "likely" (also, no scorning, remember? :) ) , - but "possible" both are, yes. Which is why i used "at least" in the post you quoted, you see.

But which way? I mean, if you say it's not 2m+ CAB average and not ~1.2...1.4m CAB average, then what is your idea? Somewhere in-between, or <1m? Intresting!
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helorime

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Re: The 2019 melting season
« Reply #4673 on: July 26, 2019, 05:17:27 PM »
I'm not sure what the best thread for this bit of new information is, as it is a general analysis of melt, but there is a brand new article out in the journal Science, released today that bodes ill for the ice in the arctic and Antarctica. 

"Direct observations of submarine melt and subsurface geometry at a tidewater glacier

    D. A. Sutherland1,*, R. H. Jackson2,†, C. Kienholz3, J. M. Amundson3, W. P. Dryer3, D. Duncan4, E. F. Eidam5, R. J. Motyka3,6, J. D. Nash2

See all authors and affiliations
Science  26 Jul 2019:
Vol. 365, Issue 6451, pp. 369-374
DOI: 10.1126/science.aax3528

    Article
    Figures & Data
    Info & Metrics
    eLetters
    PDF

Underwater melting

How fast does warm ocean water melt glaciers that terminate in the sea? That question is central to understanding how fast ice sheets may lose mass, and thus how fast sea level will rise, in response to global warming, but there are few data about the process. Sutherland et al. used repeat multibeam sonar surveys to observe an Alaskan subsurface tidewater glacier face to create a time series of its melting and calving patterns. They observed melt rates up to a hundred times larger than those predicted by theory, observations that compel us to reevaluate predictions of such ice loss."
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Csnavywx

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Re: The 2019 melting season
« Reply #4674 on: July 26, 2019, 05:22:31 PM »
8C in Eureka on a north wind. Clear skies and warm air taking over most of the CAB and CAA.

Tor Bejnar

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Re: The 2019 melting season
« Reply #4675 on: July 26, 2019, 05:23:18 PM »

 The M'Clure is terrible. … Banks and Eglinton … Prince of Wales Strait is a sickly gray; barring resupply from Viscount Melville Sound, that channel will be ice-free this summer, … 
Most of us don't know the Canadian Arctic like Ossifrage does.  Two maps on the Arctic Maps thread may assist:
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RoxTheGeologist

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Re: The 2019 melting season
« Reply #4676 on: July 26, 2019, 05:52:01 PM »
Likely that both are.
Well i wouldn't say "likely" (also, no scorning, remember? :) ) , - but "possible" both are, yes. Which is why i used "at least" in the post you quoted, you see.

But which way? I mean, if you say it's not 2m+ CAB average and not ~1.2...1.4m CAB average, then what is your idea? Somewhere in-between, or <1m? Intresting!
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For a second I thought you were describing me.

gerontocrat

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Re: The 2019 melting season
« Reply #4677 on: July 26, 2019, 06:33:48 PM »
Likely that both are.
Well i wouldn't say "likely" (also, no scorning, remember? :) ) , - but "possible" both are, yes. Which is why i used "at least" in the post you quoted, you see.

But which way? I mean, if you say it's not 2m+ CAB average and not ~1.2...1.4m CAB average, then what is your idea? Somewhere in-between, or <1m? Intresting!
Thin in some places, fat in others.

For a second I thought you were describing me.
In the interests of promoting dissension and ill-feeling here is my answer.

I was describing you, and was not being complimentary about where the fatness, and where the thinness are located.

Nothing like a bit of entirely uncalled for personal abuse to stir the juices.***
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DrTskoul

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Re: The 2019 melting season
« Reply #4678 on: July 26, 2019, 07:01:37 PM »
...and practice

Milwen

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Re: The 2019 melting season
« Reply #4679 on: July 26, 2019, 07:10:50 PM »
HYCOM - Arctic ice thickness (CICE) model - July 26 - August 2


F.Tnioli

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Re: The 2019 melting season
« Reply #4680 on: July 26, 2019, 07:45:54 PM »
...
*** In a few Old Peoples' Homes, arguments are encouraged. It seems it is good therapy instead of being drugged up in an over-heated room watching DayTime TV.. (I am prepping for old age so research is a part of the process.)
No worries - most of us have an OK sense of humor here. And it sure helps to be prepping for your later days however possible, yep. To this end, here's one super-short tutorial about one particular method of argument. Hope this knowledge will help you, if just a bit, in the future. :P
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Sterks

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Re: The 2019 melting season
« Reply #4681 on: July 26, 2019, 07:56:44 PM »
HYCOM - Arctic ice thickness (CICE) model - July 26 - August 2

<GIF of shitty model here>


If you're looking at that for an estimate of the pack edge retreat, I give you a pass. If you're looking at the thickness and believing, as somebody pointed out, that the thickness at the NP is similar to the thickness at ESS, we are in serious trouble.

bbr2314

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Re: The 2019 melting season
« Reply #4682 on: July 26, 2019, 07:57:54 PM »
HYCOM - Arctic ice thickness (CICE) model - July 26 - August 2


If you're looking at that for an estimate of the pack edge retreat, I give you a pass. If you're looking at the thickness and believing, as somebody pointed out, that the thickness at the NP is similar to the thickness at ESS, we are in serious trouble.
I don't think it's wrong, actually -- but it doesn't tell the whole story. You need to look at the concentration map as well, which shows a dramatic difference between the NP and the ESS.

gerontocrat

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Re: The 2019 melting season
« Reply #4683 on: July 26, 2019, 08:00:30 PM »
Looking at the USA Navy's Hycom over the 5 July to Aug 2 shows an astonishing loss of the thick ice north of 80 while thickness and area loss is far more muted elsewhere.



DMI's volume and thickness site is also based on the CICE model (though tweaked). And that looks somewhat different, with far more thick ice in the CAB.

And PIOMAS volume loss in the first half of July was above average, but not extremely so. Thickness in the CAB dropped by 0.3 metres.

So my major doubts are with the US Navy's HYCOM gifs.

And it is likely that in the end nothing will be conclusively proved one way or the other.
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F.Tnioli

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Re: The 2019 melting season
« Reply #4684 on: July 26, 2019, 08:00:55 PM »
I'm not sure what the best thread for this bit of new information is, as it is a general analysis of melt, but there is a brand new article out in the journal Science, released today that bodes ill for the ice in the arctic and Antarctica. 

"Direct observations of submarine melt and subsurface geometry at a tidewater glacier

    D. A. Sutherland1,*, R. H. Jackson2,†, C. Kienholz3, J. M. Amundson3, W. P. Dryer3, D. Duncan4, E. F. Eidam5, R. J. Motyka3,6, J. D. Nash2
...
I am sure it's very welcome to present the article in this thread exactly like you did, as it may be useful bit of extra understanding of this and other melt seasons for quite many people here. In the same time i am also sure that discussing details of such a paper in this topic - would not be right. So ideally such pieces are to be posted with a link to another topic where anybody who's interested to further discuss it - could do so. For example, this and this threads, while less active, - are to stay active for years, and contain quite a few arguments this new paper could change, sometimes dramatically.
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F.Tnioli

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Re: The 2019 melting season
« Reply #4685 on: July 26, 2019, 08:12:18 PM »
HYCOM - Arctic ice thickness (CICE) model - July 26 - August 2

<GIF of shitty model here>


If you're looking at that for an estimate of the pack edge retreat, I give you a pass. If you're looking at the thickness and believing, as somebody pointed out, that the thickness at the NP is similar to the thickness at ESS, we are in serious trouble.
"Shitty model" you say. Science.gov website says quite another thing, on this page. Guess who we tend to believe more: your word, or said page?

This ain't to say we diss you. This is to say we diss your post for the lack of substance. And we'll keep doing so unless you bring unbiased and verifyable arguments to the table. Days when people in this sort of debate had the luxury of trusting ones' fair word - are long gone, sadly.
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F.Tnioli

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Re: The 2019 melting season
« Reply #4686 on: July 26, 2019, 08:24:54 PM »
...
So my major doubts are with the US Navy's HYCOM gifs.
...
Jokes aside, sure, doubt is for every model, some more, some less. But there is one thing unique about US Navy's Arctic Ice matherials - which is, those guys actually go there all the time. They can and certainly do verify their model's results with actual measurements. This among other things is also military matter: certain subs have certain limits about how thick ice they can push through, and thus it's important to know where both sides' subs can possibly appear and fire away.
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TeaPotty

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Re: The 2019 melting season
« Reply #4687 on: July 26, 2019, 08:31:54 PM »
HYCOM certainly matches visual observation very well.

Here is 2012 on this date for reference:

jdallen

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Re: The 2019 melting season
« Reply #4688 on: July 26, 2019, 08:38:15 PM »
So what evidence would you look for to prove that a massive heat influx is actually taking place?
<snippage>
For area to start dropping, there must be openings larger than grid size for any given method of observation -
Norsex Arctic ROOS (https://web.nersc.no/WebData/arctic-roos.org/observation/ssmi_ice_area.png) has flatlined over the past few days despite the melt apparent on Worldview, the momentum etc. It has a coarse grid of over 10km
<snippage>
It is this fact which is exactly what I've been pondering during the recent area and extent loss slowdown(s).

When you have huge swaths of the Arctic looking like the (approximately) 100x100km2 grid below, how much melting is taking place that isn't being captured effectively by the tools?
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Dr Freeze

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Re: The 2019 melting season
« Reply #4689 on: July 26, 2019, 08:44:26 PM »
Temps during planting season 2010-2019

&

Temps rolling 7 day July to date

both click to runs

I don't like it when comparisons from different years use different colour scales to represent temperatures, it implys a greater difference in temperatures between the years.  I wouldn't have caught it if it wasn't that I thought it strange that Greenland was so much colder in 2019 than 2010.
« Last Edit: July 26, 2019, 08:49:31 PM by Dr Freeze »

F.Tnioli

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Re: The 2019 melting season
« Reply #4690 on: July 26, 2019, 08:48:11 PM »
I already mentined above, jdallen - it much depends on who's parsing the data. There are always some "agreements" as to what actually counts as "water" and what counts as "ice" for area calculations, and tresholds vary from institution to institution. DMI, iirc, is known to often have relatively stricter tresholds for example - means they'll see less of that photo of yours as "sea ice" and more as "water" than most other institutes-and-such out there. Varying grid sizes... Etc.
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Sterks

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Re: The 2019 melting season
« Reply #4691 on: July 26, 2019, 08:56:42 PM »
@jdallen, Yeah definitely. Bottom melt gradually ramping-up , all that mess over Beaufort ESS and even Laptev has time to melt out. August + 3 weeks ahead, and bottom melt doesn’t stop until end of october for the warmest ocean areas.
BTW water warmed by radiation can mix with water beneath the ice. A slow process enhanced with movement. Why people think now it’s like oil on water? In the Beaufort certainly the salinity differences are relatively small.
And even part of Chukchi water can mix while in the shelf before sinking. We see those fingers that the currents form causing eddies engulfing half the warm water and half the pack. After mixing, which takes time in those structures , density stratification is less prone to happen and water temperature beneath the ice must increase.
I don’t believe that the fast edge retreats we observe in late years is not directly enhanced by warm currents from Pacific.

Tor Bejnar

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Re: The 2019 melting season
« Reply #4692 on: July 26, 2019, 08:58:53 PM »
I expanded Jdallen's 100 km2 square and expanded it to 445 mm across and can see lots of ~4mm white spots (and bigger).  These floes are a kilometer across.  Yes, it is all a mélange that will shred itself to nothing while it melts, but a kilometer-wide floe is nothing to sneeze about.  Is (about) seven weeks enough time for it to complete the shredding and melting?  I don't know.
Arctic ice is healthy for children and other living things.

UCMiami

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Re: The 2019 melting season
« Reply #4693 on: July 26, 2019, 09:02:35 PM »
jdallen - obviously the most accurate area and extent calculations are with a large solid ice pack where grid size and or pixel count doesn't matter. The more fragmented the ice becomes the harder it is to determine actual area and extent, and as we see in high melt pond times, the more water and the darker the ice the more the sensors get confused. I don't think anyone can truly answer your question and that does not even address the fact that area and extent are two dimensional measure of a three dimensional substance and our ability and accuracy of measuring the third dimension is even more problematic. Serious melting of ice thickness can and does occur while we watch an unchanging surface measure.

All that said - we do get consistent and timely measures with equally consistent comparison values for decades of history - we can get wrapped up on daily data variations, but the bigger picture of year over year and decade by decade change is valuable and with all it's limitations seems to be a valid measure of what is happening.

Sterks

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Re: The 2019 melting season
« Reply #4694 on: July 26, 2019, 09:04:57 PM »
I expanded Jdallen's 100 km2 square and expanded it to 445 mm across and can see lots of ~4mm white spots (and bigger).  These floes are a kilometer across.  Yes, it is all a mélange that will shred itself to nothing while it melts, but a kilometer-wide floe is nothing to sneeze about.  Is (about) seven weeks enough time for it to complete the shredding and melting?  I don't know.
Yes but the ice in this state is like a fractal. You don’t see it but there are floes of all sizes. Grab Sentinel-2.
Another storm and you wont find a >250 m floe.

Sterks

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Re: The 2019 melting season
« Reply #4695 on: July 26, 2019, 09:07:47 PM »
So what evidence would you look for to prove that a massive heat influx is actually taking place?
<snippage>
For area to start dropping, there must be openings larger than grid size for any given method of observation -
Norsex Arctic ROOS (https://web.nersc.no/WebData/arctic-roos.org/observation/ssmi_ice_area.png) has flatlined over the past few days despite the melt apparent on Worldview, the momentum etc. It has a coarse grid of over 10km
<snippage>
It is this fact which is exactly what I've been pondering during the recent area and extent loss slowdown(s).

When you have huge swaths of the Arctic looking like the (approximately) 100x100km2 grid below, how much melting is taking place that isn't being captured effectively by the tools?
Would you provide coords or a link to the image? I want to see if I am lucky with Sentinel-2...
In the meantime I took this one ramdomly in a “ground” area similar to jdallen’s. The app removes the scale but take my word the biggest floes are 1 to 2 km size, the little dots that Tor describes. See the numerous floes of much smaller size, and the deteriorated state of the big ones.
https://apps.sentinel-hub.com/sentinel-playground/?source=S2&lat=78.2362955741923&lng=-130.64838409423828&zoom=13&preset=1-NATURAL-COLOR&layers=B01,B02,B03&maxcc=100&gain=0.5&gamma=1&time=2019-01-01%7C2019-07-26&atmFilter=&showDates=false&showImage
« Last Edit: July 26, 2019, 09:22:54 PM by Sterks »

ReverendMilkbone

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Re: The 2019 melting season
« Reply #4696 on: July 26, 2019, 09:19:06 PM »
Global sea ice has recovered a little.


uniquorn

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Re: The 2019 melting season
« Reply #4697 on: July 26, 2019, 09:23:19 PM »
Ice surface temperature may be relevant to some comments upthread relating to top and bottom freeze and melt. Here is DMI's map, mar21-jul25
Quote
At DMI, the temperature of the surface is not measured directly. Instead, observations are used from three infrared channels on the “Advanced Very High Resolution Radiometer” (AVHRR), which is on board the MetOp-A satellite. The instrument is unable to see through clouds, however. A statistical method is therefore used to provide the missing data. The edge of the ice is shown as a black contour line. It is defined by a sea ice concentration of 15%, i.e. 15% of the surface is covered by ice.

pearscot

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Re: The 2019 melting season
« Reply #4698 on: July 26, 2019, 09:23:26 PM »
Whenever I actually compare models, I just compare the same one against itself at different time-frames/weather events. Even if a model is 'off' and/or not taking certain factors into account, one should really only compare it to itself to filter out the noise anyways. Even at that, they are just models. For some reason it took me a while to fully understand the fact that even in periods where the extent does not drop my large amounts, vast amounts of melting is going on. In fact, I would almost venture to say that a worse scenario would be a 'large' extent but with the entire region being nothing but rubble. Scary thing is - much of the pack does look like rubble to me.
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RoxTheGeologist

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Re: The 2019 melting season
« Reply #4699 on: July 26, 2019, 09:24:53 PM »
@jdallen, Yeah definitely. Bottom melt gradually ramping-up , all that mess over Beaufort ESS and even Laptev has time to melt out. August + 3 weeks ahead, and bottom melt doesn’t stop until end of october for the warmest ocean areas.
BTW water warmed by radiation can mix with water beneath the ice. A slow process enhanced with movement. Why people think now it’s like oil on water? In the Beaufort certainly the salinity differences are relatively small.
And even part of Chukchi water can mix while in the shelf before sinking. We see those fingers that the currents form causing eddies engulfing half the warm water and half the pack. After mixing, which takes time in those structures , density stratification is less prone to happen and water temperature beneath the ice must increase.
I don’t believe that the fast edge retreats we observe in late years is not directly enhanced by warm currents from Pacific.

It's been well observed that the ice edge tracks bathymetry. The Barents continental slope often delimits the edge of the sea ice between the Barents Sea and the Arctic. This season the ice  pretty much tracks the continental slope of the Canadian Basin, except in the most southerly regions, the Beaufort. The reason is that the typically saline ocean waters cool and sink as they meet the ice edge, and that water can only sink when it reaches the continental slope.

Water temperature beneath the ice in the basins does increase at depth, but it doesn't mix with surface waters. Ice melts from the edges for a good reason. If the central pack is to melt, it isn't going to be from mixing with warm water from adjacent seas unless the ice gets spread out and deeper waters are mixed by a GAC. The Atlantic water under the Nansen basin already contains enough heat to melt all the ice. The pack will melt because it's thin and from the weather, insolation and air that is extra warm and wet because the peripheral seas have little ice.

Ice melts from the bottom, because the salinity means that it can melt at lower temperatures. if the surface of the ice is at 0°C and the base -1.8°C, any heat input into the system will melt the base at equilibrium, and not the surface. It's a balance between the conductivity of the ice, it's thickness, and how much energy is being put into the surface.