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Neven

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Re: The 2015 melting season
« Reply #2000 on: July 10, 2015, 12:00:34 PM »
Really? The shattering there goes up to about 80 degrees North.  This is 2013, at 87 degrees North, with the Pole itself at the bottom edge of the picture, just left of centre.
http://1.usa.gov/1KTYvfZ
Indeed, but we all remember that 2013 was the year of the persistent cyclones, and it is only logical for patches of open water within the ice pack to show up.

But this year there are very little diverging winds, especially in the past week with the shattering going ever further inwards, under high pressure clear skies.

I'm not saying it is unprecedented (perhaps it is), but this is all happening in situ! That's my point, not that there's open water nearing the pole (we're used to that, happens during winter even), but the fact that it isn't caused by winds, but by in situ melting.

And look at what it's doing to Wipneus' compactness graph:



Look at the dark blue trend line for the Uni Hamburg 3.125x3.125 resolution. Amazing.

Quote
It's looking quite bad, but I'm not yet ready to say it'll be as bad as 2012, or even 2010/2011.
I didn't say it either. And I don't say it because I don't think it. As things stand now, I still don't see this year make it to the top 3, but I'm not as certain of it as I was 2-3 weeks ago.

If you pushed me, I'd say that unless something happens soon to protect the Beaufort/Chukchi, then we're looking at a year quite like 2010, where there was a bunch of old ice in the Beaufort which got massacred by a huge high pressure dome, leading to a big volume drop but no new extent record.  It'll precondition things for bad years in 2016/2017, and I'd certainly expect dramatic new records by 2020 - but I'm not going to call it for this year.
Agreed. The Pacific side of the Arctic is incredibly important for sea ice pack health, and it's been under relentless attacks since the early start of the melting season.
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Glenn Tamblyn

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Re: The 2015 melting season
« Reply #2001 on: July 10, 2015, 12:39:45 PM »
The other big difference between this year and 2012 is Hudson/Baffin. In 2012 they were essentially clear. And they will clear this year just late.

So if we factor them out of our thinking, where does that leave us?

Are there any basin level measures of extent/area/volume that would allow us to discount them out.

Also combining the thickness and areal measures we seem to have two Arctic's.

  • Pacific side - still thick but declining, perhaps sharply, but lower concentration and heavily fragmented.
  • Atlantic side - thinner and not declining fast, but compact.

Irrespective of what the melt season presents, could we have a refreeze that starts with nothing but thin/missing ice everywhere? Nearly 'by by' to MYI?

Although there is no Laptev Bight so far, DMI CICE is showing a tongue of thinning ice in the Bight - sub 0.75 meter ice penetrating up above 85N, sub 0.5 meter ice 5 degrees behind it.

And if the Beaufort/Chukchi melt out to the extent that seems to be happening, what happens to the remaining thicker ice above the Beaufort - an express train ride 10 degrees further south?

I think the 'recovery' is over.

F.Tnioli

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Re: The 2015 melting season
« Reply #2002 on: July 10, 2015, 12:57:31 PM »
...

I understand where epiphyte is coming from. We are witnessing a major event in the history of Earth evolve rapidly before our eyes. Watching our predictions come true can be exciting and satisfying, but we also know that there is extraordinary risk in our grand experiment.

At times I have been struck with the feeling that we may be on the verge of creating problems that humanity cannot cope with. Assuming we haven't already crossed that line. I don't worry about that 24/7, but rapidly disintegrating Arctic ice can be enough to remind me that this isn't just a physics problem - it's an important piece of our planet's life support system.
You're late.

That feeling, is of 1970s times. It is then we were "on the verge of creating problems that humanity cannot cope with". Now, with 400ppm CO2, thawing methane and no sign of any decrease (even halting growth!) of man-made CO2 emissions (35+ Gt annually now and growing by some ~1Gt every year last ~decade), our mere existance and infrastructure is already a problem humanity can't cope with. We need to extremely rapidly decrease CO2 output, and we know it; yet we can't do it "extremely rapidly", and we also know it.

We know that if we try really very hard, may be we could stop our CO2 emissions' growth (level it, more or less, despite growing human population of Earth) - without disintegrating much/most of our "business" on the planet. Yet we know that it won't be enough to just stop it - far from. This is exactly "can't cope with", in my book.

In other words, those who spent any large effort to find out where we are - know full well that we're screwed, it's simply that most of such folks do not want to admit it in public for monetary, reputational, political, psychological or other reasons (and combination(s) of). These guys use all sorts of excuses to tell others there are (or "will be" - technofix) ways to make it through. Then, of course, all that false expressed "optimism" picks up the pace and snowballs in media and all sorts of internet talks, newspapers, etc, thus producing many times more humans - including many scientists, surprisingly - who genuinely believe that something could be done to "fix" the CO2 problem (instead of adapting to its grave consequences, long-term - for centuries to come). But in reality, analyzing every darn last seemingly constructive proposition i've found - dozens of them, - through the literature reveals impassable obstacles to practical realization of proposed long-term solutions of CO2 problem.

Basically, it's the same picture again and again: i see some rather serious scientists discussing specific methods, like CO2 sequestration, or like alternative "clean" energy sources, or like nuclear power, etc, - and it seems like "this could work", but then i go to specific papers to find out "how" proposed methods would work - and every time i find out that on required scale, it won't work. Like pumping CO2 underground, which can't be done for both physical (leaks out with time, can't keep it there for more than several decades reliably) and also economical reasons - on any significant (globally) scale; like too small economically viable potential for base-load (continuous, without long dips) power of renewables and/or their unscalability, or even straight danger and resulting ban from use (geo-thermal second generation), like short supply of traditional fuel for nuclear industry - and absense of working nuclear alternative for global scale implementation, etc.

The only practically working things i know about - are some few measures aimed at postponing the inevitable for a short time (years to few decades). Of course, in the same time such measures also have negative impact, in allowing root causes of warming to further amplify, and increase the scale and speed of the warming at a later date.

It is my understanding that even if we all would simply disappear right now, with all our emissions - it is still most likely that after several decades to few centuries, average annual surface temperature would hop up much of the space to the ~6C warmer world - which was the case (~6C higher than pre-industrial) when Earth had ~400ppm CO2 last time (some millions of years ago, literature lists various values for that period, some papers suggest as low as ~360...380ppm, some others 450ppm, etc - and noone doubts it was about +6C back then). Granted, it takes rather long time for the CO2 increase to produce the most of corresponding warming - estimates vary from ~25 to as high as ~80 years, iirc. Some 30...40 years is perhaps most often considered time for that. After that, expected at that stage feedbacks - net positive, as far as we know, - kick in, producing more forcing, and so on to the full +6C some time by year 2150...2200 or so, when Stefan-Boltzman law will ensure the new semi-equilibrium state for "hotball" Earth is reached.

Basically, it is outdated today to think "if" we can avoid devastating global warming. It is time to analyze when it will happen and what we can do about it. Some say, impossible to adapt to it; may be so, but noone knows for sure. And it doesn't mean we shouldn't try, does it.

As for depression, yes, that's a phaze of realization process. Some people get stuck in this phaze permanently, but fortunately, many move on towards more constructive - if grim - states of mind. Hopefully, you won't be stuck in any sort of "we're doomed" state of mind for any long. Unpleasant and not helpful.

I feel that at least some people who read and write about this melting season in particular are indeed well beyond the initial "despressed by discovered facts" state. But they rarely talk about it. Neither do i do it any often. But despite it being mostly off-topic in this particular discussion, i felt the need to write this all down here - not only for Nick, but possibly for other readers who feel like he does.

I hope moderators will forgive me for it. If they will, - it will be with my gratitude.
« Last Edit: July 10, 2015, 02:29:25 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!

Jim Hunt

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Re: The 2015 melting season
« Reply #2003 on: July 10, 2015, 02:33:49 PM »
A pool of water on a lake of ice with ambient air temperature reaching only 0.6 will never reach 4C.  Not in a million years.  I think that the sensor is exposed and receiving direct solar warming, possibly with the above sensors being shaded somehow.

We've had long discussions about that issue previously, but it's not clear to me that's the answer in this case. Where's the mysterious "shading" come from for example?

Some additional evidence for the phenomenon from IMB 2014I, located nearer the CAA and not showing quite so much bottom melt as yet:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/summer-2015-imbs/#2014I-Temp

2014I is a "traditional" IMB buoy, whereas 2014F is the "seasonal" variety.
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Peter Ellis

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Re: The 2015 melting season
« Reply #2004 on: July 10, 2015, 02:39:09 PM »
We've had long discussions about that issue previously, but it's not clear to me that's the answer in this case. Where's the mysterious "shading" come from for example?
*shrug* no idea, but it has to be the answer.  Andreas demonstrated it very clearly here:
http://forum.arctic-sea-ice.net/index.php/topic,1149.msg56146.html#msg56146

Unless you have some other idea for why one or two specific thermistors show a 24-hr diurnal cycle of high temperatures while others in the same string do not.  It has to be something to do with direct solar influence on specific thermistors.

It's worth doing this check for every similar anomaly in the thermistor strings, in order to rule out this effect.

Jim Hunt

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Re: The 2015 melting season
« Reply #2005 on: July 10, 2015, 02:42:15 PM »
Are there any basin level measures of extent/area/volume that would allow us to discount them out.

Yes. See Wipneus' and Chris Reynolds' excellent work collected at:

http://GreatWhiteCon.info/resources/arctic-sea-ice-graphs/#AreaRegions

and thereabouts. Raw data is downloadable from e.g.:

https://sites.google.com/site/arctischepinguin/home/amsr2/data/UH_AMSR2_3.125km_Area_Extent-v0.0.txt

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Nightvid Cole

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Re: The 2015 melting season
« Reply #2006 on: July 10, 2015, 03:31:03 PM »
Though the probabilities are obviously biased high (as Slater et al. even go on to admit), here is the latest Slater map:


Tor Bejnar

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Re: The 2015 melting season
« Reply #2007 on: July 10, 2015, 03:59:30 PM »
Neven suggested they were alien prints [edit - on ASIB today].  I concur, given that homo sapiens  (or at least the ones that probably did the walking around) are not native to this north a latitude.  One set of prints looks too in-line to be made by a bear.  Other sets seem to be back and forth on a path -  unlikely for a wild critter. [edit: Neven subsequently reported (or otherwise claims) that aliens are wearing human footwear.]
« Last Edit: July 10, 2015, 06:24:54 PM by Tor Bejnar »
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Nick_Naylor

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Re: The 2015 melting season
« Reply #2008 on: July 10, 2015, 04:30:06 PM »
The footprints are from republicans, who were gathering snow for an upcoming Senate Snowball Fight to disprove global warming. Apparently, they've run out of snow in Washington.

Tor Bejnar

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Re: The 2015 melting season
« Reply #2009 on: July 10, 2015, 04:41:10 PM »
Apparently they could just go to Boston to get 'snow' (left over from last winter), but that city is dominated by, a-hmmm, others.  Or they could go to the Californian mountains that received some 2 inches of snow last week - woops, same problem... :D
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OldLeatherneck

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Re: The 2015 melting season
« Reply #2010 on: July 10, 2015, 05:05:58 PM »
And then it might be a crew of filmmakers from WUWT doing a  documentary on summer sea ice in the Great Lakes!!
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jdallen

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Re: The 2015 melting season
« Reply #2011 on: July 10, 2015, 05:07:48 PM »
Chukchi to 82 N is not the central pack.  It is the part of the IUP bremen map that Friv posted which currently shows up as bright yellow.
Please take a closer look.  82N absolutely is within the central basin, and at least 300KM outside of the yellow zone.  That is 100% extent, and being detected as such.
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Laurent

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Re: The 2015 melting season
« Reply #2012 on: July 10, 2015, 06:25:42 PM »
If that may help to see where is what : http://imb.erdc.dren.mil/images/Arctic_regions.jpg

Gray-Wolf

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Re: The 2015 melting season
« Reply #2013 on: July 10, 2015, 08:43:53 PM »
I'm really beginning to think that this year will show just how bad the pre-conditioning of feb/march 'crackopalypse' events can be on the ice........ thank the gods we have low export!!!!!

Where heat is present and floes separate then the amount of surface area the shattered pack presents to the ocean/atmosphere must increase ablation?

Add into that the amount of ice that survived last year ( and maybe 2013 also?) but nearly melted out then we should have a lot of 'Barbers rotten ice' in among the MY ice fields and the warmth must take out the FY salty ice first? We see no change on area/extent but some of that ice must be a lot more fragile than plots suggest?
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Nick_Naylor

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Re: The 2015 melting season
« Reply #2014 on: July 10, 2015, 09:23:07 PM »
Where heat is present and floes separate then the amount of surface area the shattered pack presents to the ocean/atmosphere must increase ablation?

It's not as impactful as eyeballing it would suggest, because the floes are so darn thin compared to their other dimensions.

For example, suppose a 50km x 50km x 2m floe breaks into 2,500 pieces.
The surface area initially is (2500 km^2 x 2) + (50 x 4 x .002) = 5000.4 km^2 (.4 represents the surface area of the edges)

Afterwards, you have [ (1 km^2 x 2) + (1 x 4 x .002)  ] x 2500 = 5020.0 km^2 (20 represents the surface area of the edges)

So only a 4% [edit: make that 0.4%] increase in area from what looks like a total demolition of a large floe.

Gray-Wolf

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Re: The 2015 melting season
« Reply #2015 on: July 10, 2015, 09:28:30 PM »
Well that's my noodle cooked Nick !!! Ta for that ;D
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Peter Ellis

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Re: The 2015 melting season
« Reply #2016 on: July 10, 2015, 09:56:29 PM »
The true impact of fragmentation is not so much from the raw increase of surface area, but from capturing more of the Sun's heat and turning it into melt. Surface melt from direct insolation is more or less even across the pack.  Bottom melt from water warmed by the Sun is incredibly uneven, and depends how close the nearest patch of open water is.  Compare these two:
http://imb.erdc.dren.mil/irid_data/2014I_thick.png
http://imb.erdc.dren.mil/irid_data/2014F_track.png

Both at the same latitude, and 2014I is in an area that's much more fractured than 2014F.  Surface melt rate is almost identical, but 2014F has unbelievable bottom melt rate - presumably it is within a few metres of the edge of the floe.  The principle is clear: bottom melt attacks floes from the edge inwards.

So let's run the numbers again.  But this time instead of saying a floe fractures into 2500 pieces in situ, let's say it breaks up and spread out slightly, so it's now at 90% concentration instead of 100% concentration.

You have the same amount of ice, however:

1)  It now takes up ~11% more surface area, so it's intercepting 11% more of the Sun's rays

2)  That extra 11% of area is now open water (albedo 0.06) rather than ice/snow (albedo 0.4-0.9).  That means the extra 11% is at least twice as effective at absorbing heat, and potentially up to nine times as effective.

Together, that means that dropping the concentration from 100% to 90% will increase the amount of energy being transferred to the ice by a minimum of 25%, and could double it if the ice is snow-covered.  That extra energy will be focused tightly on the edges of the floes, hence the extreme amounts of bottom melt at the floe periphery.

Nick_Naylor

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Re: The 2015 melting season
« Reply #2017 on: July 10, 2015, 10:04:58 PM »
Don't forget, when the ice spreads out, it's not creating open water, which had to be there already for the ice to spread.

The total area of open water vs. ice hasn't changed and basically the same albedo exists over the affected area, but now you potentially have created additional ways for energy to enter the ice along the edges.

I wonder though, if heat captured by open water surrounding the large floe wasn't going into melting, where was it going? Or is it energy from below that is being made available, presumably because the fracture ice moves more and disturbs the water beneath?

slow wing

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Re: The 2015 melting season
« Reply #2018 on: July 10, 2015, 10:14:39 PM »
A pool of water on a lake of ice with ambient air temperature reaching only 0.6 will never reach 4C.  Not in a million years.  I think that the sensor is exposed and receiving direct solar warming, possibly with the above sensors being shaded somehow.

We've had long discussions about that issue previously, but it's not clear to me that's the answer in this case. Where's the mysterious "shading" come from for example? ...
Speculatively, a possible alternative giving the observed 24 hour periodicity is if the top sensors have remained a reflective white whereas the lower ones have a reduced albedo and so are heated more in the sun.

Even more speculatively, the coating might be, for example, algae or soot. The coating could have occurred, for example, from a pool that drained.

ChrisReynolds

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Re: The 2015 melting season
« Reply #2019 on: July 10, 2015, 10:22:11 PM »
We've had long discussions about that issue previously, but it's not clear to me that's the answer in this case. Where's the mysterious "shading" come from for example?
*shrug* no idea, but it has to be the answer.  Andreas demonstrated it very clearly here:
http://forum.arctic-sea-ice.net/index.php/topic,1149.msg56146.html#msg56146

Unless you have some other idea for why one or two specific thermistors show a 24-hr diurnal cycle of high temperatures while others in the same string do not.  It has to be something to do with direct solar influence on specific thermistors.

It's worth doing this check for every similar anomaly in the thermistor strings, in order to rule out this effect.

Agreed, if there is a 24 hour seasonal cycle you presume the simplest option - the sun. Then you go looking for where the shading is.

Peter Ellis

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Re: The 2015 melting season
« Reply #2020 on: July 10, 2015, 10:32:16 PM »
http://imb.erdc.dren.mil/buoyinst.htm

The thermistors are encased in a hollow PVC rod, which comes in sections for ease of assembly.  If the casing got cracked at some point (e.g. by expansion/contraction during freeze/thaw cycles), or if one of the joints came loose, then it could easily selectively expose one or other of the thermistors.  Or the string may be slightly loose inside the casing so that one of the thermistors is touching the sun-warmed PVC while others are not. Or any one of numerous other possibilities.

Fact is, you have a few thermistors that are out of kilter with their immediate neighbours and which show a diurnal cycle.  Conclusion: that data's contaminated, discard it and move on.

gerrit

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Re: The 2015 melting season
« Reply #2021 on: July 10, 2015, 10:44:27 PM »
Actually, I stand by my numbers; my estimate is based on much less than 750W/M2 - about 450 - and I'm applying Albedo before coming up with my 6CM/day estimate. 
OK, if you are happy that 450 * 24 = 18 000 (between 17k and 19k as you put it) and not 10 800, well then I don't want to spoil it for you  ;)
As for myself, I love scanning through forums like these. All the excitement and horror expressed in posts mirror the realities that the science and data present. It is also a quick and convenient summary of what is currently happening in the field.
Sometimes something pops up as just being out of range, maybe a 'bug' in your calculation. Maybe you have *40 in your spreadsheet to get to daily energy? Nothing bad about it, we all make mistakes; I thought you might just want to re-check it before you base projections on it.
Whatever the case, just know I like your posts (otherwise I wouldn't have read it in the first place) and wanted to assist.
 :)

Nix

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Re: The 2015 melting season
« Reply #2022 on: July 10, 2015, 11:27:15 PM »
Hello to All

I Have enjoyed the Sea ice forum and the wealth of information Displayed and all the  Discussion that takes place along with it... Hope this works




Interesting display of the Pacific heating and snow ice cover...

jdallen

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Re: The 2015 melting season
« Reply #2023 on: July 10, 2015, 11:51:54 PM »
Actually, I stand by my numbers; my estimate is based on much less than 750W/M2 - about 450 - and I'm applying Albedo before coming up with my 6CM/day estimate. 
OK, if you are happy that 450 * 24 = 18 000 (between 17k and 19k as you put it) and not 10 800, well then I don't want to spoil it for you  ;)
As for myself, I love scanning through forums like these. All the excitement and horror expressed in posts mirror the realities that the science and data present. It is also a quick and convenient summary of what is currently happening in the field.
Sometimes something pops up as just being out of range, maybe a 'bug' in your calculation. Maybe you have *40 in your spreadsheet to get to daily energy? Nothing bad about it, we all make mistakes; I thought you might just want to re-check it before you base projections on it.
Whatever the case, just know I like your posts (otherwise I wouldn't have read it in the first place) and wanted to assist.
 :)
Reversed digit. ☺️

~4CM/day top melt, after applying albedo. Thank you for the catch and gentle let down. This is why any good technical organization has independent quality assurance teams.

Edit:  Lets see if I can better present this 7th Grade exercise in Earth Science.

I think I will do better if I stay within the metric system rather than moving back and forth.

Numbers:   

3,340,000 Joules - the approximate energy required to melt 10 liters of ice - or - a sheet of ice 1CM thick by 1M square.

86400 - seconds in a day.

400 Watts (or Joule/Seconds)  - approximate insolation across most of the arctic at this time, averaged over the day, per square meter

34,560,000 - total watt/seconds (joules) arriving on any given square meter of surface in the arctic over a day, currently, based on my supposition of 400 Watts/M2 average.

10.3 Centimeters - approximately the ice which would be melted, per square meter, with zero albedo.

*now*, back to what I was saying before, based on this, my 6CM number was in the ballpark, even if I arrived at it by an odd route.  Given an albedo of .5 - which isn't a particularly big stretch, as at its highest, Arctic albedo is typically .85 - that means that given clear conditions, enough energy is picked up by the ice to melt just over 5CM/day.


« Last Edit: July 11, 2015, 03:04:53 AM by jdallen »
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Rubikscube

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Re: The 2015 melting season
« Reply #2024 on: July 11, 2015, 12:49:09 AM »
Where heat is present and floes separate then the amount of surface area the shattered pack presents to the ocean/atmosphere must increase ablation?

It's not as impactful as eyeballing it would suggest, because the floes are so darn thin compared to their other dimensions.

For example, suppose a 50km x 50km x 2m floe breaks into 2,500 pieces.
The surface area initially is (2500 km^2 x 2) + (50 x 4 x .002) = 5000.4 km^2 (.4 represents the surface area of the edges)

Afterwards, you have [ (1 km^2 x 2) + (1 x 4 x .002)  ] x 2500 = 5020.0 km^2 (20 represents the surface area of the edges)

So only a 4% [edit: make that 0.4%] increase in area from what looks like a total demolition of a large floe.

This effect will become significant when dealing with smaller floes though (such as 50m rather than 50 km), especially if you calculate exposure to the water line were the ice often appear to melt quickest.

Nightvid Cole

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Re: The 2015 melting season
« Reply #2025 on: July 11, 2015, 12:55:29 AM »
Really? The shattering there goes up to about 80 degrees North.  This is 2013, at 87 degrees North, with the Pole itself at the bottom edge of the picture, just left of centre.
http://1.usa.gov/1KTYvfZ
Indeed, but we all remember that 2013 was the year of the persistent cyclones, and it is only logical for patches of open water within the ice pack to show up.

But this year there are very little diverging winds, especially in the past week with the shattering going ever further inwards, under high pressure clear skies.

I'm not saying it is unprecedented (perhaps it is), but this is all happening in situ! That's my point, not that there's open water nearing the pole (we're used to that, happens during winter even), but the fact that it isn't caused by winds, but by in situ melting.

And look at what it's doing to Wipneus' compactness graph:



Look at the dark blue trend line for the Uni Hamburg 3.125x3.125 resolution. Amazing.

Quote
It's looking quite bad, but I'm not yet ready to say it'll be as bad as 2012, or even 2010/2011.
I didn't say it either. And I don't say it because I don't think it. As things stand now, I still don't see this year make it to the top 3, but I'm not as certain of it as I was 2-3 weeks ago.

If you pushed me, I'd say that unless something happens soon to protect the Beaufort/Chukchi, then we're looking at a year quite like 2010, where there was a bunch of old ice in the Beaufort which got massacred by a huge high pressure dome, leading to a big volume drop but no new extent record.  It'll precondition things for bad years in 2016/2017, and I'd certainly expect dramatic new records by 2020 - but I'm not going to call it for this year.
Agreed. The Pacific side of the Arctic is incredibly important for sea ice pack health, and it's been under relentless attacks since the early start of the melting season.

I can't for the life of me find the Wipneus compactness page - where is it?

sedziobs

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Re: The 2015 melting season
« Reply #2026 on: July 11, 2015, 02:42:10 AM »
I can't for the life of me find the Wipneus compactness page - where is it?

https://sites.google.com/site/arcticseaicegraphs/regional

Scroll down a bit.

jdallen

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Re: The 2015 melting season
« Reply #2027 on: July 11, 2015, 03:20:43 AM »
Indeed, jdallen, I also took a snapshot of yesterday's LANCE-MODIS Arctic Mosaic and this level of shattering, so far into the CAB, is simply amazing:
Looking today, that fracturing/disintegration is continuing east well into the CAB proper. That region north of the CAA is what is forecast to suffer the brunt of the heat arriving later in the week.
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Jim Hunt

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Re: The 2015 melting season
« Reply #2028 on: July 11, 2015, 09:50:22 AM »
Fact is, you have a few thermistors that are out of kilter with their immediate neighbours and which show a diurnal cycle.  Conclusion: that data's contaminated, discard it and move on.

Fact is I don't like unexplained mysteries, so I won't be moving on just yet! Two different buoys of two different designs appear to be exhibiting similar behaviour:

http://imb.erdc.dren.mil/SeasonalIBinst.htm

This morning the "pingers" on 2014F report an ice thickness of 64 cm. 2014I is a comparatively healthy 148 cm.
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Neven

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Re: The 2015 melting season
« Reply #2029 on: July 11, 2015, 09:58:52 AM »
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Neven

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Re: The 2015 melting season
« Reply #2030 on: July 11, 2015, 10:30:51 AM »
Both GFS and ECMWF now forecast a continuation of the 1020-1025 hPa high pressure north of Greenland set-up for at least up to Sunday next week.

Oh, and the Tschudi/Maslanik/Fowler ice age distribution map has been updated. I've made an animation showing week 20 to 27 (no spectacular changes):
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Jim Hunt

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Re: The 2015 melting season
« Reply #2031 on: July 11, 2015, 10:46:18 AM »
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Richard Rathbone

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Re: The 2015 melting season
« Reply #2032 on: July 11, 2015, 11:37:59 AM »

slow wing

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Re: The 2015 melting season
« Reply #2033 on: July 11, 2015, 11:55:23 AM »
Nothing too spectacular in University of Bremen's daily update of their AMSR2 ice concentration map:
  • Eastern Siberian Sea the big loser
  • Chukchi & Beaufort Seas have 'healed' a little bit if anything
  • a few melt ponds forming North of Greenland and around the Pole
  • some concentration loss in the CAA

Interesting to compare with the ice age plot posted by Neven a few posts up. The Beaufort Sea ice is mostly multi-year ice right up to the edge, with only flecks of first year ice. That seems to correspond somewhat to the concentration map - is it the first year ice patches that have mainly melted through, producing the holes?


(click on .gif to animate)



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Re: The 2015 melting seasonrr
« Reply #2034 on: July 11, 2015, 12:05:00 PM »
The 00Z GFS is epic.





Amazing really.


Here is how 2010-12 do from July 11th to 20th









Yeah funny.
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seaicesailor

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Re: The 2015 melting season
« Reply #2035 on: July 11, 2015, 12:12:33 PM »
Nothing too spectacular in University of Bremen's daily update of their AMSR2 ice concentration map:
  • Eastern Siberian Sea the big loser
  • Chukchi & Beaufort Seas have 'healed' a little bit if anything
  • a few melt ponds forming North of Greenland and around the Pole
  • some concentration loss in the CAA

Interesting to compare with the ice age plot posted by Neven a few posts up. The Beaufort Sea ice is mostly multi-year ice right up to the edge, with only flecks of first year ice. That seems to correspond somewhat to the concentration map - is it the first year ice patches that have mainly melted through, producing the holes?


(click on .gif to animate)

What about Laptev? It is opening the mouth. Baffin goes away, Hudson lost a big chunk.
Beaufort, Chukchi and ESS must have had mute decreases or some increases.
As usual, big chance that maths don't back up this map-eyeballing evaluation.

I love the battle that is going on in Beaufort. The resisting MYI blocks got some colder weather respite.
In contrast, Chukchi MYI have us disappointed. Well, the heat there is unbearable.

seaicesailor

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Re: The 2015 melting seasonrr
« Reply #2036 on: July 11, 2015, 12:17:24 PM »
The 00Z GFS is epic.

[...]

Here is how 2010-12 do from July 11th to 20th



[...]

Yeah funny.

The 2010 pattern would halt 2015 melting, wouldn't it?


slow wing

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Re: The 2015 melting seasonrr
« Reply #2037 on: July 11, 2015, 12:31:40 PM »
Will the ice minimum match 2012? I seriously doubt it.

The 00Z GFS is epic.
...
Amazing really.
Here is how 2010-12 do from July 11th to 20th
...
Yeah funny.

It's true that 2012 goes through a bad week or so from here. But the issue is that "epic" this year will only give ~3.5-4 cm/day of melt from the sun whereas a lot of ice on the Pacific side of the Pole is multi-year ice and is allegedly between 2-3 m thick and some even 3-4 m thick...

http://ocean.dmi.dk/anim/plots/ice.arc.1.png



slow wing

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Re: The 2015 melting season
« Reply #2038 on: July 11, 2015, 12:44:54 PM »
Unfortunately we can't do a direct comparison with the Bremen ice map for today in 2012 as the 2012 plots only start on the 24 July.

So here's a crazy comparison
1) today's map: 10 July 2015
2) 2 weeks on - to the 24 July, but for 2012 (is that reachable in 2 weeks??)
3) around the 2012 minimum, on 15 September 2012

Bearing in mind the ice current thickness distribution estimate shown above, it seems unlikely to me that we will lose all the way down to the 2012 minimum. In my opinion it would need a big assist from the ocean currents late in the melt season.
« Last Edit: July 11, 2015, 12:50:06 PM by slow wing »

Neven

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Re: The 2015 melting season
« Reply #2039 on: July 11, 2015, 12:48:26 PM »
I don't believe we have reached the point yet where records get broken with in situ melting only, and no compaction or export. Especially not after two rebound years. Yes, the ice pack is getting slapped hard by a warm hand right now, but more winds are needed to get things moving, literally and figuratively.

Either way, I'm enjoying watching this. It's a fascinating set-up.  :)
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Neven

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Re: The 2015 melting season
« Reply #2040 on: July 11, 2015, 12:50:18 PM »
Unfortunately we can't do a direct comparison with the Bremen ice map for today in 2012 as the 2012 plots only start on the 24 July.

On the ASIG's Concentration Maps page you can compare to July 13th. And there are links to the archives there too.
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Andreas T

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Re: The 2015 melting season
« Reply #2041 on: July 11, 2015, 12:55:18 PM »
It of course depends on what the concentration of the multiyear ice is
here is an example of a multiyear floe in the chukchi sea
go to http://1.usa.gov/1JawGdr and click through the days until today when this floe is a rather lonely speck of white in the ocean.
I expect meltrates to get quite large in that situation with the surrounding sea water warming unimpeded by other ice plus mixing away of low salinity meltwater

slow wing

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Re: The 2015 melting season
« Reply #2042 on: July 11, 2015, 12:59:17 PM »
Unfortunately we can't do a direct comparison with the Bremen ice map for today in 2012 as the 2012 plots only start on the 24 July.

On the ASIG's Concentration Maps page you can compare to July 13th. And there are links to the archives there too.
Cool! Thanks!

So is this an older satellite sensor with poorer resolution? (Still does the trick - it doesn't much degrade the comparison.)


I'm going to say that, *very* roughly speaking (yes, seaicesailor, eyes half closed), we are about level pegging with 2012 - maybe 3 days behind - in area & extent even if not in volume & thickness.

Here is 7 July 2012 and ~today, 10 July 2015...


 



« Last Edit: July 11, 2015, 01:10:10 PM by slow wing »

seaicesailor

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Re: The 2015 melting season
« Reply #2043 on: July 11, 2015, 01:05:10 PM »
Unfortunately we can't do a direct comparison with the Bremen ice map for today in 2012 as the 2012 plots only start on the 24 July.

On the ASIG's Concentration Maps page you can compare to July 13th. And there are links to the archives there too.

2015 Arctic ocean ice is the spitting image of 2007. Eyes half closed when looking at the map  8)

Neven

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Re: The 2015 melting season
« Reply #2044 on: July 11, 2015, 01:25:04 PM »
Cool! Thanks!

So is this an older satellite sensor with poorer resolution? (Still does the trick - it doesn't much degrade the comparison.)

Sorry, the archives are on the main page (AMSR-E, SSMIS, AMSR2).
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Andreas T

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Re: The 2015 melting season
« Reply #2045 on: July 11, 2015, 01:40:57 PM »
I'm just reading through this http://epic.awi.de/37371/1/tc-8-2219-2014.pdf
and thought how 2011 has a similar pattern to this year
BTW the low solar input below ice in the (modelled with ECMWF input) charts along the ice edge is due to melting of the ice shortening the time for input below the full month.
It would be nice to have those graphs for every year.

Jim Hunt

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Re: The 2015 melting season
« Reply #2046 on: July 11, 2015, 02:18:25 PM »
The latest temperature info from IMB buoy 2014I:

Pos: 75.97 N, 138.23 W
Air Temp: 0.64 C
Air Pres: 1016.15 mb
Snow Depth: 0 cm
Ice Thickness: 148 cm
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Bob Wallace

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Re: The 2015 melting season
« Reply #2047 on: July 11, 2015, 04:40:54 PM »


Quote
Here is 7 July 2012 and ~today, 10 July 2015...

The "I can see them both at the same time" version....


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Re: The 2015 melting season
« Reply #2048 on: July 11, 2015, 06:25:16 PM »
I'm really beginning to think that this year will show just how bad the pre-conditioning of feb/march 'crackopalypse' events can be on the ice........ thank the gods we have low export!!!!!


Thing is, I don't think (on the Atlantic side) export has been in reality all that low. Quite the contrary.The area and apparent concentration haven't changed very much - but  (especially in the first half of June) by following the movement of individual floes you can see that ice was drifting rapidly out of the Fram, meeting anomalously high temperature water, and disappearing without any fanfare whatsoever. I've been meaning to put together a graphic illustrating this for weeks, but have never managed to find the time.

This is one of the things that makes me wonder if the models are operating outside of their comfort zone. It's quite obvious that the ice is more fragmented and mobile that usual - In contrast with previous years, a very high proportion of it is made up of floes that are two small to see on EOSDIS. What if as  ice is exported the remainder it is just spreading out to cover the surface, rather than leaving wide tracts of open water? - If this was happening I don't think it would show up on Worldview other maybe than as late melt-ponding or persistently low albedo (both of which we saw)

Last week we saw another indication that the CAB ice is maybe less solid than it looks; the cyclone over Chuchki started pushing ice into an area of the CAB which ostensibly has 100% concentration, with so little resistance that it was spreading out as it did so leaving areas of open water reaching all the way in to the CAB. 

(to answer pearscot's question from a couple of days back) - the above is one of the things which is leaving me thinking that this may still be the year it gets real.


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Re: The 2015 melting season
« Reply #2049 on: July 11, 2015, 06:27:02 PM »


Quote
Here is 7 July 2012 and ~today, 10 July 2015...

The "I can see them both at the same time" version....



At the face of it, I don't see how 2015 is in better shape than 2012.
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