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Messages - Thomas Barlow

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1
Arctic sea ice / Re: The 2017 melting season
« on: Today at 05:06:02 PM »
Heads up. New large crack showing up in one day.
https://media.giphy.com/media/3ohzdFa2IUWIukaxu8/giphy.gif

2
Arctic sea ice / Re: The 2017 melting season
« on: Today at 05:00:58 PM »
Does the number being discussed include the Greenland Sea, Baffin Bay, Nares, CAA, even Hudson Bay?
Every square meter of oceanic water surface in NH - is included for this "practically ice-free ocean in NH" quanitification idea / agreement (sorry i don't remember where exactly i've read about it, i just remember i've been seeing it multiple times in the past). Why?
Thanks.
I'm just focus on the Arctic Ocean now, since I think (theoretically) there could be ice all over the place, even when (if) the ocean icepack ever starts to break up significantly, or shrink. What's happening in the Arctic Ocean is the main thing, re. global effect I think.

3

TomB
Does knowing that the keel of PII2012 was as deep as the Cheops Pyramid was tall help?

Interesting.
The problem with that graphic from the news article on Meunchow that I posted above is that it is squished.
The real cross-section would probably look more like this below (or much longer).
So it all depends if those cracks at the grounding line are actually that evident, or if it is just a symbol for much smaller cracks. If the former, then it's bad, especially if anomalous heat in the valley, and melt-fissures are exacerbated.
The floating ice seems vulnerable since it probably does float on the warmer waters.
So now you have warm Atlantic water eating at the grounding line, and presumably rising under the glacier, but added to that, anomalously warm Nares surface water seeping in much more than usual. So the floating ice is more vulnerable this year, and if it recedes, opens up more dark surface water, and I think, warmer air in the valley. Compounding.
It would nice to get a real cross-section, I guess the grounding line does not look as vulnerable as being suggested by some media? Unless there is a lot of seeping surface melt-water at that point.

(PS. I have camped on a glacier, just not one this big)

4
Arctic sea ice / Re: The 2017 melting season
« on: Today at 04:08:38 PM »
...
while your general feeling/concern is well based i strongly believe that "ice-free by july" is vastly exagerated. i don't even believe we shall be ice-free this year but that's at least remotely possible.

should that happen it would have to be in september but as is said, i personally don't think so.
If we define "ice-free" as "less than 1M km2 of ice area",
Does the number being discussed include the Greenland Sea, Baffin Bay, Nares, CAA, even Hudson Bay?

5
Hi Terry and Oren.
Thanks, that makes sense.
The warmer Atlantic water is percolating in over the sill and all the way into the grounding line of Petermann's with water that is at or above 0C.
So I could see how that is more constant temp., and not affected by the surface water, as you pointed out.
---> http://www.pressherald.com/2016/12/30/greenlands-thaw-melts-a-climate-change-skeptic/

“Flow of Atlantic waters into Nares Strait and into Petermann Fjord thus originates from the Lincoln Sea in the north where deep ocean temperatures at sill depth frequently exceed 0.3°C (de Steur et al., 2013). This water is warm relative to the −2.2°C pressure-dependent in situ freezing point at the base of the ice shelf …This observed heat flux is three times larger than the 1.1 × 1011 J s–1 required to melt the ~12 Gt yr–1 of ice that crosses the grounding line: for the ice shelf at its historical minimum extent of ~70 km long and 15 km wide, this is equivalent to an aerial average melt rate of 9.7 m yr–1”
http://muenchow.cms.udel.edu/papers/29-4_munchow.pdf

I guess my question to Andreas Münchow would be, has this Atlantic water flowing into the Petermann fjord become warmer because of global warming (of N. Atlantic), or has it always just eaten away at the grounding line, with enough new ice being created above, on the surface of the glacier to more than make up for the loss, increase/sustain overall mass (eg, pre-1970)?
In other words, is the main degrading of these glaciers from recently increased warmth in Atlantic waters (which seems to be suggested in the paper, but I'm not clear on it), or is potential glacier weakening coming from there being less new ice being created above? Or both equally bad?

However, I think, if the SSTs are warmer than usual in the region, the air temps will be warmer than usual, and the melting anomaly (since Aug. 2016) I posted above (Polar Portal), in the Petersonn valley, must be related to this SST anomaly? How else could a valley be warmer (melting more) than usual? Where could that warm air come from?

Can meltwater cut into a glacier causing rifts, sinkholes, and cracks? So if a weakness shows at, or near, the grounding line (or elsewhere), could that crack not be hugely exacerbated by increased meltwater on the surface of the glacier? (I think the warmer SSTs - and even lower albedo - on the Nares and Lincoln could cause the air to be warmer than usual. Can that air rise into the valley? (and the Nares has been open all winter).
I can't think what explains the extra melt anomaly in that valley, especially since it seems to face NW. Perhaps, during the day, with warmer, open water, the sun's heat is captured by the dark surface, but the albedo on the glacier would warm the air above the glacier during the day. That could cause warm, sea-level air, to rise up the valley because warm air above glacier has to rise, leaving a vacuum that must be filled (similar effects occur in valleys outside of Arctic circle, and reverse at night - wind direction changes).

If that melting anomaly goes away (it seems more at Petermann's than Humbolt right now), then that is different. (I agree you would expect to see the same in Humbolt. Humbolt may not show as much melt anomaly because it is a much wider valley? So gets a decent melt most of the time?) But as long as there is more melting than usual in Petermann's, how is that happening, other than warmer air, and is there more of a chance of cracks opening due to warmer air?

It could be that Petermann's is faster moving than Humbolt, and could pile down faster if something loosens, and it has a bigger surface melt anomaly over 10 months now.
Speed --> http://tinyurl.com/yd5cacay
(from : http://climatechangepsychology.blogspot.com/2010/11/nyt-restless-ice-greenlands-glaciers.html)

With all the cracks showing, you guys were talking about, and the melt anomaly in Petersonn's, and the warmer SSTs, and months of winter open water, perhaps something is different this year for this glacier. Worth watching the melt-anomaly this summer maybe.

Anyway, glad to hear the thickness of the glacier could be so thick, and the melt season shorter in that valley, that maybe it will not be too affected.

Thanks for all the info.

6


The reason I went looking for glaciers in the area was because of what was happening in the Nares and Lincoln right now. I thought a while back, I wonder if the event goes beyond just the channel and the 'sea'? Turns out there is probably a correlation.
Petermann's sill is located in the Lincoln Sea...
As far as warming the air over the glacier you have to remember that cold air follows a glacier down hill and blows any SST warmed air away from the glacier.

As far as I know neither SST nor ice cover has any connection to calving of marine terminating glaciers. The deeper, warmer waters undercutting the tongue eventually lead to calving. 
Terry

I see. Thanks.
I'm not sure what the relationship of the 'sill', deep in the Lincoln Sea to Petermann's can be? That seems to refer to ancient geology? Where the ancient geological terminus of a much bigger multi-glacier complex may have been?
That warmer SSTs could flow into the fjord seems plausible. Or just getting warmed on the spot by the regional effect of lowered albedo (ever since the sun hit this spot in mid-March), causing warmer air temps than usual. The regional effects of such a huge area of dark water seem probable.

It does seem to me that the air would be in a constant flow down the valley, day and night, unlike a valley outside the Arctic circle (where it alternates wind direction, day and night, due to difference in warming and cooling rates of land and sea-surface, but I'm not sure how that would work on a glacier.) It seems that the wind would be constantly flowing down the valley, day and night, as you suggested?

As in the above image of accumulated melting anomalies (presumably meaning surface air temp. anomalies as well - by correlation), it seems that the glacier has warmer than usual air temps., and that must be because of a regional effect, most likely connected to the low albedo in the Nares, and now the Lincoln. Just guessing. Maybe not?

I think the top image here could have a melting effect on the Fjord sea-ice, compared to the lower one from (roughly) the same date in 2016 for example ? The earlier in the season the sea-ice in the fjord melts (which I think it will - it is more than a month ahead in the Nares right now), surely that will have an effect on the terminus of the glacier itself? Maybe my understanding of glaciers and fjords is too limited.

7
We're in a period of peak tides, with a couple of days to go, the break up in Lincoln can only let in more N Atlantic water which flows far into the fjord. I don't expect anything major in the next few days, but we'll see,
I don't see the connection between the break up of Lincoln Sea ice & more water flow into Petermann Fjord. What am I missing?
Terry
Maybe the almost consistent warmer air and SST anomalies going for months now, in the Nares, links then all? And this has led to the early Lincoln break-up, which will probably just accelerate now, and expand. And the SSTAs will infiltrate the bay, and, by summer, the glacier terminus, as air temp. anomalies settle over the glacier itself.

The reason I went looking for glaciers in the area was because of what was happening in the Nares and Lincoln right now. I thought a while back, I wonder if the event goes beyond just the channel and the 'sea'? Turns out there is probably a correlation.

8
Accumulated (melting - mass loss or gain) Anomaly since Sept. 1 2016:
http://polarportal.dk/en/groenlands-indlandsis/nbsp/isens-overflade/

9
What's interesting in the long-term, is that the Petermann valley appears to be an almost totally sub-sea-level valley, and maybe the only one that goes all the way to the ancient inland sea of Greenland !
https://arstechnica.com/science/2014/05/greenland-may-lose-more-ice-than-expected/


12
Any thoughts on the state of the Petermann Glacier right now, May 27, in relation to open Nares and Lincoln Sea, and warmer SSTs ? And likely near future?

13
Arctic sea ice / Re: The 2017 melting season
« on: May 26, 2017, 03:42:29 PM »
Looking only at the Arctic basin (instead of overall extent or thickness for the Arctic Circle and beyond) using DMI, I think it's fair to say that the icepack is not as robust this year as last year.

14
Arctic sea ice / Re: The 2017 melting season
« on: May 25, 2017, 03:22:20 PM »
]If Nares does not block up, what happens?
https://media.giphy.com/media/l0IycQAX8BRdZcIQE/giphy.gif

15
Arctic sea ice / Re: The 2017 melting season
« on: May 23, 2017, 03:52:50 PM »
The people saying that the ice is breaking up in smaller blocks appear to be right.
Was the winter freeze, with all its anomalously warmer temps., only enough to cement small, broken-up blocks together, rather than create any significant new thickness or extent, creating an illusion of relative stability in area?
"""Polar bear scientists see unusual sea ice breakup""
http://www.ktuu.com/content/news/Polar-bear-scientists-see-unusual-sea-ice-break-up-423713633.html

16
Arctic sea ice / Re: The 2017 melting season
« on: May 22, 2017, 10:01:30 PM »
Where did it go?
Charts show this ice that's now  entering Nares to be old thick ice, but the way it crumbles makes for doubt. 5-21 vs. 5-22
i was just looking at that.
The ice is being reported as 4-5 m thick ice, but is being pulverized as it enters the Nares. Seems surprising. 

17
Arctic sea ice / Re: The 2017 melting season
« on: May 21, 2017, 08:20:47 PM »
Can you point me to the site? (worldview)

---> http://tinyurl.com/nykf7bz

18
Permafrost / Re: Arctic Methane Release
« on: May 21, 2017, 06:27:55 PM »
Surges of algae growth in the summer may be followed by high emissions of methane and CO2 in the fall. I don't dispute what this study observed but the scientists should be very careful not to extrapolate a summer bloom with reductions in CO2 and methane emissions. Several studies over the past several years have found unexpectedly high releases of CO2 and methane in the fall when sunlight is gone but temperatures are still pretty warm and ice is thin or not present.
The jury's out, but would the high releases of CO2 and CH4 in the Fall be enough to cancel out the Summer's "1900 times more CO2 being absorbed than methane being emitted" as the study suggests? One would have to compare tonnage.
Although methane is a much worse GHG in the short-term, so then you would have to figure out if "1900x" is enough to compensate for any balance of the scales on year-round Arctic methane release to the atmosphere.

Maybe nature has its own 'carbon credits' system?

19
Arctic sea ice / Re: The 2017 melting season
« on: May 21, 2017, 06:18:10 PM »
All the ice between the Beaufort and Chukchi is starting to break up.
A close up look.

A lot of peripheral regions seem to be disintegrating now. Including the Lincoln Sea, which is unusual (maybe unique). Because of its position in the jigsaw puzzle, it could be the straw that breaks the donkey's back. (I hope not.)

20
Arctic sea ice / Re: The 2017 melting season
« on: May 19, 2017, 04:48:25 PM »
TB - Wipneus tracks grpahs or Arctic Basin area and extent, which excludes all peripheral seas but includes the seas adjacent to the CAB. I think this is what you are asking for.

Thanks to everyone for pointing me to the CAB charts. I'm bookmarking all of these.
This one seems to be showing 2nd lowest in recent years right now (with that weird, but unsustained dip in 2016 beating it out).

21
Arctic sea ice / Re: The 2017 melting season
« on: May 19, 2017, 05:15:28 AM »
Beaufort joined to Nares?

22
Arctic sea ice / Re: The 2017 melting season
« on: May 18, 2017, 02:33:55 PM »
I saw this surprising chart on Jim's site. I didn't think 2017 was tracking 2016 in this region, was quite sure it was lagging.

Compare and contrast. Beaufort open water is behind last year, balanced by Chukchi & ESS ahead of last year:

Is there a graph (comparing years) that takes out the CAA and everything else that is not really in the Arctic Ocean?

23
Arctic sea ice / Re: The 2017 melting season
« on: May 17, 2017, 03:51:00 PM »
"Is there any significant MYI left in the Lincoln Sea?"
Yes, but it's more like ice clinging to land at this point, rather than significant part of the icepack
will the apparently thinner stuff coming into the Nares strait and eventually to Baffin Bay be easier to flush out ?
Nobody knows. I was trying to see how that would go. If you look at the ice thickness map over time, it looks like thick ice is being sucked down that drain (the Nares), and thinner will follow it. And with SSTs higher than the norm., I suspect it will flush through.

24
Permafrost / Re: Arctic Methane Release
« on: May 15, 2017, 06:29:12 PM »
There is emphasized the relationship of 1:2000 - one part upwelling methane could trigger the photosynthesis uptake of 2000 parts CO2...That the photosynthesis in the end is only doubled compared with the water enviroment is not said exactly.
Doubling the photosynthesis causes 1:2000 ratio is the point I think.

I don´t believe the algae will be a real sink for carbon - most of them don´t sink down and as a lot of fishes and other marine life is extremely threatened
Fishes, seaweed, sharks, and whales take on carbon as cleaners of the oceans. That's their job. An extra bit of carbon won't hurt them, or anyone who eats them. The biggest problem there is the over-fishing of the ocean, and also plastic particle soup in the ocean, turning them acidic. Also Fukushima could be bad. Also pollution dumped directly into ocean by cities and international shipping. And, of course, the oceans do absorb carbon from the atmosphere, so become more acidic.

That the algae effect will not work in dark winter is also not told by GEOMAR-also it is transfered to areas with shallow waters... It is even told that methane is not proven to cause the upwelling of nutrisious waters-in contrast to Sciencemag article.
They did say it in the article about the dark winter (at the very end). The whole fear of melting icepack is that in the summer it could lead to more methane release. In the past, the large summer icepack would trap methane before it is released, and it was quickly absorbed by natural mechanisms. Now, that icepack is more and more open in summer, shallow seabed regions more likely to melt. As far as I know, winter is not as big an issue, due to icepack cover over the Arctic Ocean (except in land permafrost maybe).

The jury's out on this effect, maybe it needs to be included in modeling to see what happens, but if the methane sensors are correct, the methane is rising as far as I can tell.

Another interesting effect I saw ---> https://scripps.ucsd.edu/news/biological-activity-found-affect-aerosols-produced-sea-spray

Maybe Gaia is real.



25
Arctic sea ice / Re: The 2017 melting season
« on: May 14, 2017, 04:26:41 AM »
I keep wondering: will the debris from this breakup clog Nares Strait or will it just flush through? So far, it is flowing smoothly.
I was wondering about that, and I suppose higher SSTAs that can be seen, may make a smooth passage more likely if they are the norm.

26
Permafrost / Re: Arctic Methane Release
« on: May 13, 2017, 12:02:25 AM »
What happens to the algae though? Does it actually sequester the carbon by dying and getting buried by silt at the bottom of the ocean or just die and decompose in the water column? If it does that, then this is just a roundabout way of adding carbon to the carbon cycle.

I believe it sinks. Also, it takes bacteria with it. Other creatures will eat it and (later) die and sink.

PS.Whales are considered large carbon sinks too, both in their effect as they have to rise near the surface to deficate, which creates algae, and the same CO2 sequestration effect.
 Also, churning the lower and upper layers.
They also take on a large amount of carbon, and when they die. they (usually) take that to the bottom of the sea as well, and the rotting carcass acts to create more biological activity that sequesters carbon for decades.
https://en.wikipedia.org/wiki/Whale_fall
Therefore ... Save the Whales.

27
Permafrost / Re: Arctic Methane Release
« on: May 11, 2017, 11:57:14 PM »
;D wish I would have some more time to dig in-but I think it is not worth it. Intention seems to be to spread doubts and to give the mainstream media with the Sciencemag article stuff to tell some good news about methane.


That was my first reaction, but it seems legit science, and I doubt there is any "intention" here.
They are just doing a scientific experiment and getting it published, like any other scientists. They state that it is small-scale.
It's published in PNAS.
http://www.pnas.org/content/early/2017/05/02/1618926114
However, I do agree that it seems unlikely that this algae effect would slow the observed methane rise. Perhaps in the shallow ocean, yes, I could see that.
Perhaps "Slow the rise of global warming a little" should have been emphasized more. Especially since it is just one small experiment.
And I can't see it happening in the permafrost on land. However, there may be other factors at work in the permafrost that could slow the release from being 'catastrophic'.
Unlike many, I am open to being wrong about the dangers of methane (a view which I have supported for years) if more research is done, I will change with the science, if it is legit.
And the researcher did state that this only applies to daylight-time in the Arctic, not the night of winter.

There is no question in my mind that the increase in algae could naturally sequester CO2 and slow warming, but enough to make a real difference to global warming? ... I can't see that happening unfortunately.

Juries' out on this I think. Time, and more experiments will tell.
However, monitoring shows Arctic methane continues to rise:
https://www.esrl.noaa.gov/gmd/dv/iadv/graph.php?code=BRW&program=ccgg&type=ts(

28
Permafrost / Re: Arctic Methane Release
« on: May 11, 2017, 05:21:34 AM »
"Are methane seeps in the Arctic slowing global warming?"
http://www.sciencemag.org/news/2017/05/methane-slowing-global-warming-arctic

31
Arctic sea ice / Re: The 2017 melting season
« on: May 10, 2017, 06:59:45 PM »
SST and SSTAs seem pretty high in Chukchi sea.
How will this impact that area as the season progresses?

32
Arctic sea ice / Re: The 2017 melting season
« on: May 07, 2017, 04:11:49 AM »
It seemed to me like 2008 had relatively thin ice in May, and not record setting low volume in September?
Although 2008 had a lot more reds and pinks than current.
Don't know if that made a difference. Seems unlikely, since they are crunched against CAA mostly.
I am not expecting record setting low area in September, based on this, but close.
(I'm using May 2, because DMI seems to be stuck on May 2 right now.)

(ice just above 1.5m thick)

34
Arctic sea ice / Re: The 2017 melting season
« on: May 06, 2017, 09:13:25 PM »
Looking at these comparisons from DMI and Hycom I'm having some thoughts:
* Obviously thickness in early May is not a very good predictor of location of remaining ice in September. I guess movement during the season is a large part of that.
* Some might be explained by latitude, as ice below 80 deg has a lower chance of surviving for a given thickness, while ice at 85 deg on the Atlantic side may still thicken more during May.
Hard to predict, yes. Here is the movement, month to month, for 2016. Always ends up clumping up against CAA and Greenland.
https://media.giphy.com/media/3og0IGrFYUSA6F65dC/giphy.gif
* Some might be explained by model inaccuracies, as DMI is not known for its good volume estimates. Maybe a PIOMAS cutout of current date in 2016 vs. remaining ice at min 2016 could shed some more light or expectation for this year, though it seems there is just not enough information yet.
It would be interesting to put a DMI graph and a HYCOM graph with the 2016 annual curves together on one chart, adjusted for graph scales, and include one or other of their 'margin of error' ranges. I think they would both seem pretty similar compared to the margin of error. I think there are none of them that super-accurate, and I very much doubt the US navy, since they are only concerned with places a ship could get through. I doubt they are too concerned with great accuracy. I take all of the systems as just rough estimates really.
* The Hycom comparison for the 2.5m ice in 2017 compared to 2015 and 2016 is shocking.
It is pretty wild looking.

35
Arctic sea ice / Re: The 2017 melting season
« on: May 06, 2017, 04:05:52 PM »
Here is just over 1.5m thick ice for May 2, 2016, alongside Sept. 15th 2016 minimum.
Below that is May 2, 2017, with just over 1.5m thick ice.
The 1.5m+ version does seem closer in area at first glance, since the 2m+ version seems too small an area when comparing the 2016 May and Sept. (area) versions (because of how the area tends to move towards the Atlantic side eventually.)

36
Arctic sea ice / Re: The 2017 melting season
« on: May 06, 2017, 03:53:45 PM »
So I would say 2.5m thick ice is also surely vulnerable, depending on latitude and mobility, possibly even thicker than that. If you put the May map side by side with the same map at the Sep min, some more insights might arise.
Here is just over 2m thick, and below that, just over 2.5m thick, for May 2.

37
Arctic sea ice / Re: The 2017 melting season
« on: May 05, 2017, 05:58:05 PM »
Here I took out everything about 1.75 meters thick and compared it to 2016.
Looking at just the main area of the Arctic Basin here.
If you think of yellow (3m thick) and yellow-green, as showing robust state of Arctic Basin, then 2016  maybe looks more spread out across the icepack than today (as well as thicker reds (5m) in 2016).
In terms of melting, has a certain thickness in early May been generally observed to survive the summer melt? I'm guessing 1.5 meters is vulnerable (putting aside concentration for a minute here, since a lot of 3m ice is usually pretty concentrated.)

38
Arctic sea ice / Re: The 2017 melting season
« on: May 05, 2017, 05:40:32 PM »
Stunning aprupt upwards movement of the Extent Graph of Bremen...  :o

In this region it looks like the channels in the CAA, and the Fram/Atlantic, as well as the Nares Straight have more extent than 2016 for example. I wonder if that adds to it? Fram could be mostly export. Nares and Fram could be Greenland melt, freshwater that cools the surface (floats on salt water, and is cooler, and also freezes more easily). But I think it is mostly export.

39
Arctic sea ice / Re: The 2017 melting season
« on: May 04, 2017, 03:32:38 PM »
Not sure which thread to post this in, but is this unusual? Is it relevant to Arctic?
Today's jet stream:
https://media.giphy.com/media/xUPGcoh39ZKjSAlIju/giphy.gif




(from: https://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-62.81,40.95,555 )

40
Arctic sea ice / Re: The 2017 melting season
« on: April 29, 2017, 02:25:53 PM »
Interesting graphic, really looks like where ice is close to 100% concentration it's thinner and areas with thicker ice are more fractured.

My take on it is that there are areas of thick, concentrated ice, and thinner ice. The Beaufort, for example, is relatively thick and relatively concentrated at this time compared to the main area of weakness which is towards the Russian (east) side, where the blue areas are thinner and less concentrated, and the intrusions of blue into the thicker areas should be note for concern, since those look more advanced than usual.  It's early days yet, but still gives an overall sense.

41
Arctic sea ice / Re: The 2017 melting season
« on: April 27, 2017, 02:01:05 PM »
This mixes (colors) concentration with sea-ice thickness maps, so the blue areas (not deeper purples, or reds and blacks) show where the vulnerability is, being both thinner, and slightly lower concentration. Reds, blacks, and deeper purple, show thicker, more concentrated ice.

42
Arctic sea ice / Re: The 2017 melting season
« on: April 26, 2017, 05:44:23 AM »
It might be interesting if they didn't include the years from 2010 onwards in their "Mean Volume".

Does anyone have the data skills to create such a chart? ... with only 1979-2010 included for the average (black-dotted line).
It would be interesting to see the difference in the chart, caused by the last several low-volume years.

Here's a crack with a line for 1979-2010 added.

We'll see what September 2017 brings us, but it seems clear that there is a good chance that we are about to find out if the Arctic summer melts ice 'volume' or if it melts 'extent'.
I'd guess both. If less thick ice becomes the norm, as it may be heading for this year, then more open areas by August 1st are likely. After that, extent could drop precipitously.

43
Arctic sea ice / Re: The 2017 melting season
« on: April 25, 2017, 12:20:51 AM »
It might be interesting if they didn't include the years from 2010 onwards in their "Mean Volume".

Does anyone have the data skills to create such a chart? ... with only 1979-2010 included for the average (black-dotted line).
It would be interesting to see the difference in the chart, caused by the last several low-volume years.

Here's a crack with a line for 1979-2010 added.
Ok, not a huge difference, but thanks for doing that !
Interesting to see.

44
Arctic sea ice / Re: The 2017 melting season
« on: April 24, 2017, 11:48:36 PM »
It might be interesting if they didn't include the years from 2010 onwards in their "Mean Volume". Including those just makes the average descend down the chart each year, and gives a false impression, because the most recent years are lowest on record, and declining more as we speak. The average from 1979-2010 would be much higher up on the chart, and it would show we are in a precipitous decline in the last 5-7 years, at least compared to the average of modern records.

Does anyone have the data skills to create such a chart? ... with only 1979-2010 included for the average (black-dotted line).

I suspect a certain flightless bird with a drippy nose could crank that out.  He's already doing other charts with the PIOMAS data. 

Let me add, I think that's an excellent idea.  Moving the goalpost is hardly ever a good idea.
Who?
(who is the flightless bird. Can he do it?)

45
Arctic sea ice / Re: The 2017 melting season
« on: April 24, 2017, 11:46:41 PM »
Interesting.
According to this - http://polarportal.dk/en/havisen-i-arktis/nbsp/sea-ice-extent - a lot of 5m thick ice off Ellesmere island & Greenland, but open water in channel. Strange.

46
Arctic sea ice / Re: The 2017 melting season
« on: April 24, 2017, 11:34:13 PM »
Interesting.
North Pole ice is 2.75m thick, whereas it was 4m+ thick this time last year.
No wonder Barneo did a retreat.
http://forum.arctic-sea-ice.net/index.php/topic,1905.msg111027.html#msg111027

47
Arctic sea ice / Re: The 2017 melting season
« on: April 24, 2017, 11:19:45 PM »
A year on year look at the Beaufort. Far less cracks. Give it time though I suppose.

According to this, it is much thicker in the peripheral Beaufort than last year.
(but thinner elsewhere in the Arctic this year, than 2016)

48
Arctic sea ice / Re: The 2017 melting season
« on: April 24, 2017, 03:27:42 PM »
It might be interesting if they didn't include the years from 2010 onwards in their "Mean Volume". Including those just makes the average descend down the chart each year, and gives a false impression, because the most recent years are lowest on record, and declining more as we speak. The average from 1979-2010 would be much higher up on the chart, and it would show we are in a precipitous decline in the last 5-7 years, at least compared to the average of modern records.

Does anyone have the data skills to create such a chart? ... with only 1979-2010 included for the average (black-dotted line).
It would be interesting to see the difference in the chart, caused by the last several low-volume years.

49
Arctic sea ice / Re: The 2017 melting season
« on: April 23, 2017, 01:33:13 PM »
I just added " >1.5m " ice to the bottom of my post on previous page (18), re. ice thickness in the Arctic Basin 2016 vs 2017.
Even more interesting.
Unfortunately, it's not looking very robust.

Click here, scroll down ---> https://forum.arctic-sea-ice.net/index.php/topic,1834.msg110856.html#msg110856

50
Arctic sea ice / Re: The 2017 melting season
« on: April 22, 2017, 11:28:51 PM »
This compares thickness, for certain thickness ranges only.
Between 2016 and 2017.
(I'm guessing most sources out there are just approximate, with a wide margin of error?)

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