Author Topic: Fragmentation Event. Will it have impact over the summer melt season?  (Read 28690 times)

Gray-Wolf

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We have all been captivated by the scale , and speed, of events in the basin over the past few weeks and so I thought that maybe we needed a dedicated thread to discuss the matter?

I am sure that this event will have important impacts on ice levels come melt season but how do you guys see things playing out? Both in terms of how far will this event run ( will it impact the whole basin?) and then what will the fracturing mean once melt season comences proper?
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Artful Dodger

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #1 on: March 06, 2013, 03:17:24 PM »
Good question, Gray-Wolf

I think it comes down to the remaining MYI along the Canadian Arctic coast. If it breaks loose and enters the gyre, it's game over. Within 3 years all the MYI will be gone, flushed out Fram Strait in the first complete revolution of the BG. 3 years max, because some or all may melt first in the warming Southern Beaufort sea.

If some of the MYI pack resists and stays stuck above the CAA, then it's not over yet. It will still have a CHANCE, although not a certainty, of surviving.

We should know by the time the current Arctic vortex collapses. That intense high-pressure system is doing as much mechanical damage to the main ice pack as the GAC of Aug 2012 did to the periphery of the pack.

This may be the main event, the heavy-weight battle to end the career of an aging and punch-drunk fighter.
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Espen

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #2 on: March 06, 2013, 03:52:10 PM »
 Yes the situation is pretty bad north of CAA, and the results of this sea ice on the loose is clearly seen on this Russian Ice Chart, try to flicker the images from the beginning of January, and you will see a lot of MYI exported true Fram.
The edge of the MYI to the north from Russia is almost reaching the north pole now, best seen on the latest image in March.
But one strange thing though is the lack of the fast ice reaching out from  the Joekelbugt / Shannon Island area, there is almost nothing left of it.
And then some good news, the winter is over and Good Old Petermann, will show up on today's Modis images, let the season start!!! 8)

Yes I forgot to answer, yes this Fragmentation Event will have big consequences for the whole Arctic Sea this season!

http://www.aari.ru/odata/_d0015.php?lang=1&mod=0&yy=2013
« Last Edit: March 06, 2013, 04:09:53 PM by Espen »
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Gray-Wolf

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #3 on: March 06, 2013, 04:10:57 PM »
Thanks Guy's!

If the event is able to break into the CAA 'Rump end' ice then we also have the problem of swell penetrating through the area 'nibbling away at the edges of the floes? Catlin certainly had issues with swell under 2m of ice but if that ice is also fractured then the wave action could lead to even more disruption prior to melt season proper?

And if such an ice mass encountered something like GAC12???

It's like looking at various asteroid types. We used to have a metal one, we moved onto a rocky one and now we may be left with a rubble pile.

From a distance (i.e. most folks perspective) they all look the same but boy do they behave differently!

If we are left with a 'rubble pile' then I imagine both the gyre and trans polar drift will take it's toll (both the Alaskan coastal warmth and the Pacific warmth in front of Bering for the gyre) but I fear Fram most with the Trans polar shoving everythin before it in the direction of the Atlantic Swan dive. With last years melt along the north coast of Greenland I believe that the 'rump end' has lost the last bit of purchase it had and so will quickly be able to float out toward the Drift once the next high tides disrupt the coastal fringes.

We know the F.Y. ice does not do a good job of surviving an 'average summer' so to lose a percentage of the ice we rely on for a September presence even before melt has begun would not bode well for the season.

Up until this fracture event (I was looking out for the spring tide full moon disruption) I thought the season may end up similar to last years. Since I've seen what is ongoing in the basin my thoughts are all back up in the air!

Could it mean that the unthinkable could now occur this year?

Could a lean toward a 'high transport' synoptic, early in the season, be the only extra shove  (on top of this fracture event) needed to see us slip below 1 million in late Aug?
KOYAANISQATSI

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ChrisReynolds

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #4 on: March 06, 2013, 05:04:38 PM »
The portion of MYI that has broken off will move into Beaufort in the next few months, this will melt in the summer. I'll repeat the graphic I've just posted on another thread here:



The dotted area shows ice that hasn't moved significantly, the arrows connect features who's movement has been used to estimate ice movement. From this you can see that the MYI has cleaved, whether this process eats further into the pack remains to be seen.

However that situation isn't in essence different from other years. Ice used to cycle and age in the Beaufort flywheel, now ice that enters that region is melted out. What it different now is that there is so little MYI, such a large chunk going ensures that a dip in the age profile will carry forward over the coming years.

Likewise this movement of the pack is a common event, although the resultant break up in Beaufort does seem early.

However this event is not in itself significant. It confirms the ice is thin, is something the models, ASCAT, and reasoning from last year's minimum have already told us - most of the pack is now first year ice. What matters for this year is the state the 2012 melt left the ice in. This fracturing will not play the biggest role.

Shared Humanity

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #5 on: March 06, 2013, 05:19:23 PM »
Chris........Wasn't there a large pack of thick ice that broke away from the main pack last summer? It drifted out into the Chukchi Sea and hung out near Wrangel Island until it completely melted out after the GAC. Are you suggesting that the MYI that has fractured from the other MYI could suffer the same fate? What should be looking for early in the melt season to indicate this is likely to happen?

Espen

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #6 on: March 06, 2013, 05:20:22 PM »
Chris,

I believe you can reduce the height of that pyramid within the dotted line before the end of the month or in other words, its area can be reduced by at least half.
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Jim Williams

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #7 on: March 06, 2013, 05:26:43 PM »
However this event is not in itself significant. It confirms the ice is thin, is something the models, ASCAT, and reasoning from last year's minimum have already told us - most of the pack is now first year ice. What matters for this year is the state the 2012 melt left the ice in. This fracturing will not play the biggest role.

This seems right to me.  The fracturing is more a part of last Summer's melt than the cause of this coming season's.  Sure it means something.  It means that there's no real volume left.

Gray-Wolf

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #8 on: March 06, 2013, 05:35:42 PM »
I suppose the other thing to keep in mind is what is occurring below the ice? We know from various expeditions that swells can push under 2m thick ice but with the pack fragmented will this allow further , more vigorous, wave action to mix up warmer waters from below the ice base?

GAC12 was able to do a lot of mixing last summer (plenty of melt horizon was mixed away) so will we have a 'fatter' layer of warmer waters at depth?

Maybe the Fragmentation will allow bottom melt to re-commence in some areas as warmer ,saltier waters are mixed to the surface (and the winters halocline is mixed out)?
KOYAANISQATSI

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ChrisReynolds

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #9 on: March 06, 2013, 06:08:03 PM »
Shared Humanity,

MYI is regularly pushed into Beaufort every year, it's just that now it melts out. I do expect the section that's broken off the MYI core to suffer that fate, how it will work out I cannot say.

Espen,

I suspect not, at present I don't see strong evidence of preliminary fracturing. And looking at the image above it seems to me there's a levering action going on, that is now largely spent with the two large fractures we've been following.

Jim Williams,

It'll be interesting to see what PIOMAS volume is for February.

Gray-Wolf,

The large amount of FYI formation last autumn will have created cold dense brine that will have interrupted Arctic ocean stratification, and may have brought Atlantic Water into contact with the ice. The current new formation of ice in the fractures may be doing something similar.

BornFromTheVoid

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #10 on: March 06, 2013, 08:29:35 PM »
Large crack in Arctic sea ice, February 2013

Jim Williams

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #11 on: March 07, 2013, 02:35:08 PM »
The large amount of FYI formation last autumn will have created cold dense brine that will have interrupted Arctic ocean stratification, and may have brought Atlantic Water into contact with the ice. The current new formation of ice in the fractures may be doing something similar.

Do you think we'd have the lens sandwiched between brine, or the brine falling through and mixing with the lens?

I've been thinking in terms of the lens being disrupted by wind during the Summer, but you are suggesting another and perhaps sooner possibility.

I certainly think that if (when) we get significant contact of Atlantic water with the ice pack then the ice is gone.  If (when) the Atlantic water stays at the surface during Winter then the Winter ice is gone too.

ChrisReynolds

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #12 on: March 07, 2013, 06:28:17 PM »
Jim,

The Atlantic water is IIRC around 100m deep (at it's upper layer), so wind would have to be pretty strong to cause mixing. However increased dense brine formation in the autumn has been observed in models as a factor in increasing warm water intrusion under the ice. The cold brine rejected from the ice is, as far as I'm aware, likely to be denser than the AW layer, so would fall through and disrupt it, causing mixing.

Just remembered - the paper is Holland et al "Future abrupt reductions in the summer Arctic sea ice", which shows that RILEs are thermodynamically driven with increased ocean heat transport having a role.
http://shadow.eas.gatech.edu/~kcobb/abrupt/holland06.pdf

I've been sceptical of claims that AW is playing a strong role in past ice loss simply because it's so deep it's not in direct interplay with the ice. Also while relatively warmer it's still cold, most of the heat is lost in transport to the north from the tropics. However it seems reasonable that could now be playing a more active role in ice loss - I base this on the assumption that we're in a RILE and that modelled RILEs show ocean heat transport having a role.

Vergent

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #13 on: March 07, 2013, 09:38:34 PM »
Large crack in Arctic sea ice, February 2013


I have not decided which is more disturbing, the ice shattering, or the arctic sunrise marching toward the pole, while the ice shatters.
The only authority I seek is logic... Vergent

TerryM

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #14 on: March 07, 2013, 10:19:45 PM »
A few years back a British team found that where FYI dominant it was so salty that the cold melt water was mixing to 200 meters below the surface. The warmer waters being displaced were having the effect of increasing bottom melt.

http://www.cbc.ca/news/canada/story/2011/06/28/arctic-ice-melting.html

The effects of Ekman pumping from low pressure systems following retreating ice edges adds to the mixing resulting in ice bathing in warmer waters than would be the case with MYI.

Terry

Jim Williams

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #15 on: March 08, 2013, 01:59:59 PM »
Just remembered - the paper is Holland et al "Future abrupt reductions in the summer Arctic sea ice", which shows that RILEs are thermodynamically driven with increased ocean heat transport having a role.
http://shadow.eas.gatech.edu/~kcobb/abrupt/holland06.pdf


Very interesting article Chris.  Kind of seems like the models are describing what's been happening, with the timing being off.

I still think the fetch on long stretches of open ocean can cause pretty deep mixing, but the models and data looks to me like I don't need this assumption to come to the same conclusion.

http://www.cbc.ca/news/canada/story/2011/06/28/arctic-ice-melting.html


Thanks Terry,

These observations might be confirming the models in terms of what happens.  The analysis of the data seemed to reach a similar but slightly different conclusion.  Again, it seems that in terms of timing the data disagrees with the models considerably.

ChrisReynolds

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #16 on: March 08, 2013, 06:38:54 PM »
Jim,

You can see the AW layer in this profiler.
http://www.whoi.edu/page/preview.do?pid=111896

The top two plots are temperature, the lower going to a greater depth and showing the warm Atlantic Water (AW) layer - which in this region is warmer than I'd thought by a degree or so. It remains quite stable with deep mixing events being notable. However on the whole the AW layer remains pretty stable. Unfortunately these profiler bouys only give data in ice covered areas, as far as I can see.

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #17 on: March 08, 2013, 07:08:47 PM »
Am I right, there is no literature on synoptic scale sea ice collapse events?

Does anybody sees a connection to the Beaufort freshwater bulge described here: http://www.nerc.ac.uk/press/releases/2012/01-arcticwater.asp ? Maybe rotation of z axis is not the only thing going on.

These constantly opening cracks turn the Beaufort in an ice fabric, producing fresh ice in Winter, like the Laptev does. However, I think the overall net effect is thin ice got build thick ice got exported.

IIRC, there is a plan of a future year round US science station in the Beaufort. Sounds rather adventurous, now.


ChrisReynolds

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #18 on: March 10, 2013, 10:03:27 AM »
Arctic.io,

There's a lot of literature on such events. I've posted a paper on that here, but can't recall which thread, and could have been on Neven's blog.  :-\

Here's a paper I just found on Google.
http://www.igsoc.org/journal.old/37/127/igs_journal_vol37_issue127_pg319-322.pdf
Note that figure 1 shows fracturing in Beaufort that could pass for this year. Which is why I've been very specific about what I see as unusual.


anonymous

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #19 on: March 10, 2013, 05:08:17 PM »
I think unusual is the scale. The current event goes beyond Beaufort Sea. On the other hand cracks are nothing special in the Arctic. It appears difficult to attribute single cracks to single events and thus get a picture of the overall size.

ChrisReynolds

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #20 on: March 10, 2013, 06:05:47 PM »
I'm still not convinced that what's happening now is unusual, or tells us much about the condition of the ice. What we need is a stock of satellite images back to the 1970s - precisely what we don't have. As cracking of the ice is evident back to the 1980s and most of the thinning happened after then, I don't think we can draw the conclusion that the cracking in the bulk of the pack is unusual. However I failed to find similar cracks to the massive arc fracturing event in winter QuikScat, so I still think that was unusual, and its progression does, I think, show thin ice.

Neven

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #21 on: March 10, 2013, 08:08:41 PM »
Those cracks in the Beaufort are huge. That cannot be a regular event. And this is coming from someone who went through all wow-phases in the past three winters. I get mails all the time from people seeing something on satellite images or wherever (and I don't blame them) which make me go: probably not unusual.

But find me instances of this around this time of the year:



I don't know, I didn't look at all the possible images out there, but it wouldn't surprise me if this isn't more than the usual.
« Last Edit: March 10, 2013, 08:20:25 PM by Neven »
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Artful Dodger

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #22 on: March 10, 2013, 08:35:45 PM »
Those cracks in the Beaufort are huge. That cannot be a regular event. And this is coming from someone who went through all wow-phases in the past three winters...

I don't know, I didn't look at all the possible images out there, but it wouldn't surprise me if this isn't more than the usual.

Hi Neven,

This is pretty straightforward to settle, at least for the period over which we have MODIS imagery. Attached are 4 images take on Day 90 (just after MODIS sunrise at the N. Pole, around March 31) for each of the last 4 years: 2009, 2010, 2011, & 2012.

"Yes, we have no bananas".
« Last Edit: March 10, 2013, 09:58:02 PM by Artful Dodger »
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Artful Dodger

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #23 on: March 10, 2013, 08:55:18 PM »
On 2012.090  (March 30, 2012) you can see the beginnings of a breakup underway in the Southern Beaufort sea. Nothing like the vast breakup of 2013, and 22 calendar days later in the season.

For comparison, here is yesterday's 3-6-7 Arctic Mosaic from the MODIS instrument:
« Last Edit: April 09, 2013, 12:12:47 AM by Artful Dodger »
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Neven

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #24 on: March 10, 2013, 09:20:44 PM »
Yes, that's what I mean. Grazie.  :)
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Jim

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #25 on: March 10, 2013, 11:57:12 PM »
Chris Reynolds linked to a paper in 1991 reporting on the fracture of ice in 1983 here: http://www.igsoc.org/journal.old/37/127/igs_journal_vol37_issue127_pg319-322.pdf.

The pattern of cracks and leads seen in February 1983 is very similar to those seen this month, so this is probably not as unusual as we might think. Note that the ice was much thicker then and with this years ice being thinner and weaker than before, perhaps we shouldn't be all that surprised?


Neven

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #26 on: March 11, 2013, 12:15:55 AM »
If that is Banks Island on the right, then those cracks are somewhat near the Canadian coast:



Now look again at this picture:



My eyeball tells me you could fit Banks Island in that big lead!  :P

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Peter Ellis

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #27 on: March 11, 2013, 12:40:30 AM »
Your eyeball is wrong by approximately a factor of 4.

Using the scale provided at http://www.arctic.io/observations/ the lead you have boxed is about 60km wide at its widest.
« Last Edit: March 11, 2013, 12:45:59 AM by Peter Ellis »

Artful Dodger

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #28 on: March 11, 2013, 03:28:05 AM »


My eyeball tells me you could fit Banks Island in that big lead!  :P

Hi Neven,

Is this image taken from Arctic Mosaic 500 m imagery? If so, then your red-rectangle is 60 km wide by 110 km long.

If this image is from 1 km imagery, then the red-rectangle is 120 x 220 km. Etc.  ;D

The point is that the 2013 breakup is BASIN WIDE. There is no indication that has ever occurred before, including 1983.

For further discussion, please find attached the PIOMAS hindcast for sea ice thickness for March 1983, and the DMI 80N Temp chart for 1983:
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Neven

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #29 on: March 11, 2013, 08:43:04 AM »

Hi Neven,

Is this image taken from Arctic Mosaic 500 m imagery? If so, then your red-rectangle is 60 km wide by 110 km long.

If this image is from 1 km imagery, then the red-rectangle is 120 x 220 km. Etc.  ;D

It was taken from the 2 km imagery of the entire mosaic. If Banks Island still doesn't fit, we'll have to devise a way to make it smaller.
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ivica

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #30 on: March 11, 2013, 09:46:00 AM »
...If Banks Island still doesn't fit, we'll have to devise a way to make it smaller.
Naah, Nature could make them fit soon.  ;D
« Last Edit: March 11, 2013, 09:52:06 AM by ivica »

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #31 on: March 11, 2013, 09:49:39 AM »
To stick with Grey-Wolf's question: I can't see how this event could have no consequences. So many fractures on such a large area, occuring at the end of the freezing season... It reminds me of the Larsen B ice shelf in Antarctic (though it was much, much thicker).

Neven

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #32 on: March 11, 2013, 10:23:47 AM »
If those huge leads and coastal polynyas stick around with just a thin layer of FMI (first month ice) until the Sun comes out to play, there will be a lot of holes in the pack early on. But I suppose there will be some compaction before that.
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Apocalypse4Real

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #33 on: March 11, 2013, 07:49:28 PM »
A source I have in the US White House responded to a query with the following:

Arctic sea ice area and extent in March/April are no predictor of September minimums.

That said, the 2012 summer average Arctic temperatures were unprecedented relative for which we have instrumental records. (We noted they are still above average in Spring, 2013).

There is an upcoming paper in Nature showing that recent Arctic summer temperatures are unprecedented for the last 600 years.

The source concludes that historical records may provide a poor precedent for the future.

Unusual events now could well be indicators of more to follow later in the season.

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #34 on: March 14, 2013, 01:44:52 AM »
Ever more apparent cracks in the heart of MYI paralleling the coast of the CAA, seen today after the New Moon/Spring tide.
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Apocalypse4Real

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #35 on: March 14, 2013, 02:05:26 AM »
Lodger,

I saw those, and think that is not the end, despite the compaction that may be coming in 3-5 days, given the HYCOM/CICE ice motion forecast.

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #36 on: March 14, 2013, 06:27:49 AM »
Lodger,

I saw those, and think that is not the end, despite the compaction that may be coming in 3-5 days, given the HYCOM/CICE ice motion forecast.

Yes A4R,

I think the entire pack is mobile now. ANY strong wind will move the not-so-fast ice away from the CAA, either flushed out Fram into the Atlantic graveyard, or sent spinning South for a Beaufort burial-at-sea.

People don't realize that this is ALL about survival of the MYI. Anywhere with FYI will melt out now over Summer. The relentless melt of 2012 regardless of conditions proves that the Arctic has crossed the tipping point were unguarded FYI can survive a season on its own.

Only where there is MYI (discussed in Neven's "The Arm" blog in Sep 2010 or "Stronghold" in Jul 2012) can there be any hope of sea ice survival.

Now, 2013 is highly likely to see the very last of the MYI moved South and melted. If 2013 is a favorable season for melt conditions, it'll all go this year. If not, then the following year.

This cracking event is the death knell for the Arctic sea ice.
« Last Edit: March 14, 2013, 07:54:34 PM by Artful Dodger »
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ritter

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #37 on: March 14, 2013, 05:32:32 PM »
This cracking event is the death knell for the Arctic sea ice.

It certainly looks that way.

Is there a mechanism where the fractured MYI recompacts or does it just split apart into smaller chunks drifting about and subject to increase melting from the increased surface area?

Apocalypse4Real

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #38 on: March 14, 2013, 07:02:02 PM »
The next 5 days sees the Polar high rebulld to a 1061 mb center practically over the pole. The wind pattern will be fairly strong and continue to rotate the ice. More interesting is the influxes of warmer air due to a low that will blow into Baffin Bay and into the Norwegian and Barents Seas.

Artful Dodger

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #39 on: March 14, 2013, 08:02:50 PM »
This cracking event is the death knell for the Arctic sea ice.
Is there a mechanism where the fractured MYI recompacts or does it just split apart into smaller chunks drifting about and subject to increase melting from the increased surface area?

Hi Ritter,

Compactness isn't the real issue with MYI, it's mobility. When the old, thick MYI was latched fast to the CAA, it was durable since it can only be affected by bottom melt or surface ablation.

Now that MYI is mobile it will move South, either into the Beaufort gyre or Fram strait. And we know how that ends.

If you mean some form of healing of the cracks, then no there is no mechanism. It is easy to see with time-lapse animations how larger angular ice floes always break into smaller rounder ice floes.

Maybe we should call it the Beaufort grinder?  :-\
Cheers!
Lodger

ritter

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #40 on: March 14, 2013, 10:10:59 PM »
This cracking event is the death knell for the Arctic sea ice.
Is there a mechanism where the fractured MYI recompacts or does it just split apart into smaller chunks drifting about and subject to increase melting from the increased surface area?
If you mean some form of healing of the cracks, then no there is no mechanism. It is easy to see with time-lapse animations how larger angular ice floes always break into smaller rounder ice floes.

Yes, I suppose healing of the cracks is what I meant by recompaction. I've enough real world experience with ice blocks keeping an ice chest cool to know that the smaller the chunks, the faster they melt away...

I was hoping you'd tell me the coming wind pattern would push the MYI back together and some form of seal or polar bear snot would bind it again. Seemingly, we need that kind intervention.

Carex

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #41 on: March 15, 2013, 01:02:56 AM »
Arctic ice blog fame continues to grow.  The Climate Central article on the arctic cracking was picked up and re-posted by The Weather Underground.  Their graphics are a bit old and of limited area (not A-Team quality) but awareness is slowly slipping out.

Artful Dodger

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #42 on: March 15, 2013, 02:31:08 AM »
I was hoping you'd tell me the coming wind pattern would push the MYI back together and some form of seal or polar bear snot would bind it again.
Hi Ritter,

Classic. ;D

I have also been inspired: "Beaufort gryndre"  :-\
Cheers!
Lodger

Artful Dodger

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #43 on: March 15, 2013, 04:48:01 AM »
The forecast map for SLP looks deadly for the MYI pack North of the CAA from this Sunday to Tuesday (see attached map).

Look at the isobar lines on the map. Winds direction is parallel to the isobars, and in the clockwise direction in a high pressure area. Wind speed is greater where isobars are closer together.

Colour on this map codes the predicted 500mb geopotential height. To explain, 500 mb is the normal pressure at about 18,000 feet altitude (important because this is the normal height of the storm track). So when you see the 560 mb colour indicated for 500 mb geopotential height, that is very high pressure, comparable to having 1073 mb SLP.

Note also that the forecast map illustrates Wayne Davidson's hypothesis about the new cold North pole: the Greenland summit. The High seems to emanate from that location. This configuration seems common this Winter.
« Last Edit: March 15, 2013, 05:12:31 AM by Artful Dodger »
Cheers!
Lodger

werther

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #44 on: March 15, 2013, 09:35:02 AM »
Morning Lodger,

I’ve clicked through the ECMWF free access 10-day forecast too. And like you, I saw some remarkable patterns emerging. Another blocking event over Greenland combined with a ‘warm high’ filling in the high Arctic. The last one slipping in from the Chukchi sector.
Once again, we’re not seeing the ‘transport-band’ that kept the Barentsz-Kara region amazingly ice-free like a year ago.

I honestly find it very hard to get a notion of what this winters’ patterns are cooking up for the next melting season. I saw some ‘traditional’ parameters indicating help for sea ice. FI extent, area, extreme Feb cold, positive SST anomaly gradually weakening.
I have too small background to say anything reliable on whether these winter patterns are decisively different from other years. But I have a gut feeling they are. We enter the change of season in both hemispheres with another large scale reset (another SSW/NH? What about ENSO etc).

In the Antarctic, the lasting pattern over the Peninsula changes, finally warming the region, hurting the enormous Weddell FYI pack and driving up SST in the Amundsen Sea.

In the North Atlantic, record negative NAO. Very high SLP around Iceland, very low to the West of the Iberian Peninsula.

And yes, the remaining ‘safe-pack’, 1,8 Mkm2 ‘mesh-pattern’ coherent ice with the left-over MYI could be dragged out direction Beaufort/Chukchi for days.

Apocalypse4Real

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #45 on: March 15, 2013, 03:45:43 PM »
Werther,

Things are messy, and seem to be getting weirder as we move into the next week or so. Attached are:

1) the current surface temp anomaly, which shows strong anomalous warming at the surface,
2) the NAO forecast, which seems to depict another negative NAO record coming,
3) the OSU forecast for 031913 0000 GMT, which shows a 1068 mb high over the CAB, but with 20 kt winds over the CAA, and warmth over Norwegian and Barents Seas. See: http://polarmet.osu.edu/nwp/animation.php?model=arctic_wrf&run=00&var=plot001 for the animation,
4) Finally, the HYCOM ice motion is depicting full grynder mode for March 21. See  http://www7320.nrlssc.navy.mil/hycomARC/navo/arc_list_arcticicespddrf.html for the whole forecast.

Each day of warmth, wind, and heightened sea ice motion moves us closer to maximum extent - and melting.

wanderer

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #46 on: March 15, 2013, 05:24:34 PM »
I wonder, wether the extent (and probably also area and volume) measurements are correct these days...

When I look at this:
http://neven1.typepad.com/.a/6a0133f03a1e37970b017ee95104a5970d-pi

and at that:
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png

I don't think that all the cracks are included (or rather subtracted from) in satellite measurements, although this pic: http://neven1.typepad.com/.a/6a0133f03a1e37970b017ee951744f970d-pi
seems to get all the little cracks.

Can anyone tell me, if the measurements DO subtract those little (or not so little) cracks?

gfwellman

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #47 on: March 15, 2013, 06:29:11 PM »
I think it's pretty clear that the main area and extent maps (CT, Uni Bremen, NSIDC) are not showing the cracks.  That's actually reasonable, because at current temperatures the cracks are no doubt filled with nilas ice or other very thin ice.  How PIOMAS incorporates such information is beyond my knowledge.  CT area has taken a slight bump up, but not much, so I doubt it's wrong by much.  Any effect will be temporary, just like the "melt pond effect" later in the season is temporary.

CraigsIsland

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #48 on: March 15, 2013, 07:29:09 PM »
A4R- nice little synopsis of current conditions. It does look like we'll be seeing some interesting results in the next 1-3 weeks with these conditions lined up :(.

Neven

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Re: Fragmentation Event. Will it have impact over the summer melt season?
« Reply #49 on: March 15, 2013, 09:41:47 PM »
Can anyone tell me, if the measurements DO subtract those little (or not so little) cracks?

The cracks are quite quickly covered with ice and thus get counted for extent, area and concentration. If they weren't covered with ice they would show up on the sea ice concentration maps, get counted on the area graphs, but not completely on extent graphs.
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