Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: Gray-Wolf on March 06, 2013, 02:04:40 PM

Title: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Gray-Wolf on March 06, 2013, 02:04:40 PM
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?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen 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 (http://www.aari.ru/odata/_d0015.php?lang=1&mod=0&yy=2013)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Gray-Wolf 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?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds 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:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Ffarm9.staticflickr.com%2F8248%2F8534579476_7aa84d8919_o.gif&hash=bbadfb2a10fed0f1b42ec049f6d85842)

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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Shared Humanity 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?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Williams 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Gray-Wolf 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)?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: BornFromTheVoid on March 06, 2013, 08:29:35 PM
Large crack in Arctic sea ice, February 2013 (http://www.youtube.com/watch?v=AEHnQZcbYVo#)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Williams 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds 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 (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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on March 07, 2013, 09:38:34 PM
Large crack in Arctic sea ice, February 2013 (http://www.youtube.com/watch?v=AEHnQZcbYVo#)

I have not decided which is more disturbing, the ice shattering, or the arctic sunrise marching toward the pole, while the ice shatters.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: TerryM 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 (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
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Williams 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 (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 (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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds 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 (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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: anonymous 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 (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.

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds 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 (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.

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: anonymous 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven 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:

(https://lh6.googleusercontent.com/-a1pYrEXOibU/UTzZoYlYSxI/AAAAAAAAAUo/Z8UlALsZQ-k/s540/cracksbeaufortmarch2013.jpg)

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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger 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 (https://www.youtube.com/watch?v=jT6JkceQ9FU)".
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger 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:
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven on March 10, 2013, 09:20:44 PM
Yes, that's what I mean. Grazie.  :)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim 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 (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?

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven 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:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.jimmymack.org%2Fimages%2Fmaps%2FBanks_Island.png&hash=4bde411f5371554663b4f2e8ff0a763d)

Now look again at this picture:

(https://lh6.googleusercontent.com/-a1pYrEXOibU/UTzZoYlYSxI/AAAAAAAAAUo/Z8UlALsZQ-k/s540/cracksbeaufortmarch2013.jpg)

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

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Peter Ellis 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/ (http://www.arctic.io/observations/) the lead you have boxed is about 60km wide at its widest.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger on March 11, 2013, 03:28:05 AM
(https://lh6.googleusercontent.com/-a1pYrEXOibU/UTzZoYlYSxI/AAAAAAAAAUo/Z8UlALsZQ-k/s540/cracksbeaufortmarch2013.jpg)

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:
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ivica 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
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: DungeonMaster 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).
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger 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 (http://neven1.typepad.com/blog/2010/09/the-arm.html)" blog in Sep 2010 or "Stronghold (http://neven1.typepad.com/blog/2012/07/stronghold.html)" 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ritter 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?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger 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?  :-\
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ritter 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Carex 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger 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"  :-\
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: werther 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real 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 (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 (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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: wanderer 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 (http://neven1.typepad.com/.a/6a0133f03a1e37970b017ee95104a5970d-pi)

and at that:
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png (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 (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?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: gfwellman 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: CraigsIsland 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 :(.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven 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.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on March 15, 2013, 10:18:23 PM
I wonder, wether the extent (and probably also area and volume) measurements are correct these days...


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

The cracks are counted as ice because they are iced over. The maps you linked to have temperature scales. the cracks are in the -10 to -20C range. Sea water freezes at -2C

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.aari.ru%2Fresources%2Fd0015%2Farctic%2Fgif.en%2F2013%2F20130312.GIF&hash=0c78ac45fa816188b3298cc03e657311)

This map shows that the cracks are 10-30cm thick. The water is at its freezing point and the air is way below it so the cracks freeze over almost instantly. Open water would be obscured by a black(warm) cloud of "ice smoke"(fog).

Verg
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: werther on March 16, 2013, 01:14:03 AM
Following the post above, in which I admitted I found it very hard to get a notion of what this winters’ patterns are cooking up for the next melting season, I’ve been rambling through NCEP/NCAR comparing the general winter 500 Mb ‘steering pattern’.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1036.photobucket.com%2Falbums%2Fa446%2Fhanver1%2FArctic%2520ice%25202013%2FGeo500Mbano15091303201310metersmall_zps22a0b00c.jpg&hash=ead002314dcdaf0f5e1dac3d23ff5e58)

I used the period 15 September to 13 March (available for this season too) as perimeters.
Over the period ’95 to ’13 I get the strong impression that the Northern Hemisphere winter is gradually showing larger areas of anomaly, becoming mainly positive.
What could it mean? I see this as an indication that the pressure gradient between the tropics and the Pole is weakening. This seems to fit the mechanism eloquently advertised by FI Dr. Francis.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1036.photobucket.com%2Falbums%2Fa446%2Fhanver1%2FArctic%2520ice%25202013%2FGeo500Mbano15091303201310metersmall_zps22a0b00c.jpg&hash=ead002314dcdaf0f5e1dac3d23ff5e58)

This winter especially featured a very large positive anomaly. IOW, the thickness of the lower troposphere was actually larger than usual (albeit just 50-100 m). The area covered a large banana-shaped stretch all the way from the Bering, over the Laptev and Greenland into Labrador, about 13 Mkm2. It may have influenced the strength of the zonal winds, the steering, over the sub-boreal zone. In that sense, it did contribute to all confusing messy weather since last September.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Meirion on March 16, 2013, 03:19:39 PM
VERGENT - love the St Petersburg Institute ice map - my question is how do you get the up-to-date chart because when I go to their site and hit "last one" I get old maps.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: crandles on March 16, 2013, 03:35:21 PM
Meirion, does this do it?

http://www.aari.ru/odata/_d0015.php?lang=1&mod=0&yy=2013 (http://www.aari.ru/odata/_d0015.php?lang=1&mod=0&yy=2013)

Neven graph page still links 2011 instead of 2013. But I can select 2013 from year drop down box in top left corner. So I am not sure where you see the "last one" link.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on March 17, 2013, 01:58:03 AM
VERGENT - love the St Petersburg Institute ice map - my question is how do you get the up-to-date chart because when I go to their site and hit "last one" I get old maps.

In the top left there are boxes for year and date: Select 2013 you will get the latest map.

http://www.aari.ru/odata/_d0015.php?lang=1&mod=0&yy=2013 (http://www.aari.ru/odata/_d0015.php?lang=1&mod=0&yy=2013)

Neven's link is out of date, this one will take you to the latest 2013 map
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger on March 17, 2013, 03:12:09 AM
Discovery News (http://news.discovery.com/earth/oceans/arctic-storm-fractures-sea-ice-130316.htm) picks up the story, credits A-Team/ASI blog.

Que the mongrel horde (http://www.motherjones.com/politics/2013/02/donors-trust-climate-denial):

www.youtube.com/watch?v=IaKm89eVhoE (http://www.youtube.com/watch?v=IaKm89eVhoE#ws)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Meirion on March 17, 2013, 06:15:50 PM
Ta Crandles and Vergent. That does the trick
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: supaluminal on March 18, 2013, 12:29:22 PM
I'm trying to think how I would (naively) construct a volume model such as PIOMAS, to try and get a handle on how it might deal with such cracking. This is pretending that we haven't seen a cracking event like this before, so it's more like the "normal" arctic:

If a crack opened up, the area in that crack might count as 0 m of thickness, but given that most cracks probably wouldn't have opened up like this previously, the assumption might very well be that it is the same (or similar) thickness to the ice surrounding it. This would invariably have the effect of reporting an anomalously high volume. Even if the effect wasn't absolute, and cracks were assumed to have thinner ice, it would still report a higher volume than was accurate.

I don't know how PIOMAS actually accounts for such an event, but if the cracking occurs only on a small scale, then the effect wouldn't be significant, and the way it is modeled wouldn't be so important. But with this event being so widespread, what are the chances that PIOMAS is counting a great deal of the iced over cracks as the same or similar thicknesses to the ice surrounding it. If that is the case, then that calls into question the rebound in PIOMAS values for the first 2 months of the year.

I guess we'll know once that weak ice disappears under the impact of the sun...
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on March 18, 2013, 06:34:11 PM
Supaluminal,

There is no way to naively model sea ice, it is too complex. I'm in the process of re-reading the three papers that outline the maths behind PIOMAS, if you want I can give you refs and links.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on March 18, 2013, 07:05:05 PM
http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/piomas-thickness-maps/ (http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/piomas-thickness-maps/)

They have not yet published PIOMAS thickness maps for Jan. and Feb. It will be interesting to see how it handles the cracks.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Carex on March 18, 2013, 11:50:36 PM
We now have cracks throughout the Arctic Basin, the Beaufort looks like confetti, the Chukchi has been pumping ice in and out of the Bering Straight (we know that's mobile), the Kara looks like a dropped egg, there are vast areas of open water (or very young ice) in the lee of Wrangle Island in the East Siberian Sea.  But what effect will it have?  That depends on the melt season's weather.  A calm season will see little effect but any storms, especially large storms will be able to pound the ice into nothing or push it into warmer water.  It's fate isn't sealed but it is much more vulnerable.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on March 19, 2013, 01:43:58 AM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Flance-modis.eosdis.nasa.gov%2Fimagery%2Fsubsets%2FArctic_r03c03%2F2013077%2FArctic_r03c03.2013077.terra.1km.jpg&hash=6590630dd1391b74a4920949bf6467ec)

The cracking has progressed clear to the north coast of Greenland. It has become jagged in the thick old MYI.
Title: Gargantuan crack to come next week?
Post by: Nightvid Cole on March 19, 2013, 03:37:22 AM
According to http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf/nowcast/icespddrf2013031718_2013032500_035_arcticicespddrf.001.gif (http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf/nowcast/icespddrf2013031718_2013032500_035_arcticicespddrf.001.gif)   , there will be a line of extreme ice divergence through the central Arctic (passing approximately though the North Pole), parallel to the CAA coast, presumably this will create a crack as the ice has insufficient tensile strength to withstand it.

Could this be the greatest crack of them all?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on March 19, 2013, 04:31:46 AM
Vergent's visual did not come through, but here is the 0102 GMT imagery for Ellesmere and the entire CAB.

I think that we will see the Lincoln Sea fracture this week.

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: jdallen on March 19, 2013, 05:17:11 AM
Greetings all;
I'm a lurker who's been following events here for several weeks, but has been following environmental issues since the first earth day.  I've determined its time to stop lurking.

I am agog at the scale of what's happening right now along the CAA.  I think as "A-Team" mentioned, as regards to the health of arctic ice, nothing positive can come from this.

The scales of energy at play in this, are almost incomprehensible; I was thinking earlier, as we saw the first events in the Beaufort, that part of what was in play was what amounted to a massive kinetic "hammer" coming down on the apex of the MYI left over from 2012.  I still think, as well as currents and wind, pure momentum may have a part to play in what we are seeing here.

I say that, in what paltry scientific education I have (former Geologist turned systems analyst here), I see significant corollaries between what happens in crystalline structures to cleavage when pressure is applied in two dimensions along a plane, and how the fracture zones are developing across the arctic.

We shall see how this plays out, with the coming sun.
Title: Re: Gargantuan crack to come next week?
Post by: ChrisReynolds on March 19, 2013, 07:57:41 AM
This is a coastal flaw lead, they're not uncommon, but this one does seem to be uncommonly extensive.

If you check out what has happened in Beaufort instead of a series of parallel arc fractures the ice has pulled away from Banks Island opening up a polynia that has covered with new thin ice. Something similar may happen in reality, as compared with the model. We may not see a single fracture, rather more fracturing inside the pack.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven on March 19, 2013, 11:05:31 AM
Nightvid Cole, I merged your thread with this one because it's no use having two threads about the same event. Somehow your OP got lost during the operation, and only Chris Reynolds' reply got posted (above this comment). I'm really sorry about that! I merged threads once before and everything seemed to work fine.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: supaluminal on March 19, 2013, 11:52:21 AM
Supaluminal,

There is no way to naively model sea ice, it is too complex. I'm in the process of re-reading the three papers that outline the maths behind PIOMAS, if you want I can give you refs and links.

I probably used too strong a word in naive, I guess i was more thinking about a model that was based on the way the ice has been for the last couple of decades, which I would expect PIOMAS to be, and therefore, a model that may have trouble with unexpected occurrences.

As for the papers that cover the maths behind the model, hell yes, count me in. I've been breaking things apart to find out how they work since I was a kid, I don't see why I should stop now.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Gray-Wolf on March 19, 2013, 04:15:21 PM
I think the past couple of melt seasons have highlighted that we can no longer view the Arctic's behaviour by looking at past analogues? When synoptics that used to protect ice now actively destroy it things have become well out of kilter?

The same must be true of the winter Arctic with so little ice left in the basin to fend off tide and synoptics. This current event surely shows us that we should 'expect the unexpected' these days?

 Sure we saw fragmentation events in the past (I used to wait for the 'spring tides' to highlight how fragile sections of the basin's ice was becoming!) but never on this scale or duration?

With Spring now upon us we shall all have a front row seat in seeing just how such disruption aids , or hinders?, melt.

Last year we saw a lot of 'blue ice' early on in spring as the snow cover melted and the melt-waters flooded the flat surface of the FY ice. This season that water may be channeled into the ocean rather than standing around the ice surface lowering ice albedo?

Will the re opening of the leads lead to swells that mechanically smash the larger floes down in size and so hasten their melt?

How early do we expect to see the majority melt to be over by? Late July? If so what chance the remainder ice with open water mixing out any 'melt horizon' and bringing warmer, saltier waters to the surface? Would an earlier melt out lead to more L.P. systems running around the basin (mixing out the river runoff in the 'Beaufort lens'?)

I don't know how to call it, how can I? we have never seen the likes of this before.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on March 19, 2013, 06:53:51 PM
Supaluminal,

The main paper on which the PIOMAS model is based is:

Zhang et al, 2003, "Modeling Global Sea Ice with a Thickness and Enthalpy Distribution Model in
Generalized Curvilinear Coordinates"
http://psc.apl.washington.edu/zhang/Pubs/POIM.pdf (http://psc.apl.washington.edu/zhang/Pubs/POIM.pdf)

This is in turn based on:

Hibler, 1980, "Modelling a Variable Thickness Ice Cover."
This should be readily locatable via AMS journals, top hit in Google with the above paper title.
This paper gives a lot more detail about the thermodynamics of the model than the PIOMAS paper above.

Finally there is Zhang & Rothrock, 2001, "A Thickness and Enthalpy Distribution Sea-Ice Model"
<a href="http://journals.ametsoc.org/doi/pdf/10.1175/1520-0485(2001)031%3C2986%3AATAEDS%3E2.0.CO%3B2">PDF</a>
This paper gives some more detail about issues like ridging of ice, and the treatment in the model.

At present I'm trying to get a grasp of the cause of the more aggressive spring melt post 2010. I suspect it's in the transfer from old to young ice throughout the pack. I'm just checking again to see if these three papers might explain why (mechanistically) thinner ice might melt more rapidly in PIOMAS - if I can't get to the bottom of it I'll email Dr Zhang.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven on March 19, 2013, 08:55:14 PM
Hello, Mr Blue!

(https://lh3.googleusercontent.com/-bdoj2FHuoWM/UUjBfLH2rEI/AAAAAAAAAZ0/Fu-3ZOtFS1M/s576/mslp_latest.big.png)

The AO Index agrees:

(https://lh5.googleusercontent.com/-ufmiKMjgjj4/UUjCZtFC0aI/AAAAAAAAAag/GCdKah_eS-Q/s720/ao.obs.gif)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Shared Humanity on March 19, 2013, 09:18:50 PM
The Fram express is now a bullet train?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on March 19, 2013, 09:35:14 PM
The Sea Ice Grinder is entering into Lincoln Sea in direction of Cape Sheridan, I don't believe the "solid" Sea Ice in the area will survive much longer, the question now will this action enter Robeson Channel and the rest of Nares Strait too?

NB: Please use the 250 meter image enlargement below!

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r03c03.2013078.terra (http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r03c03.2013078.terra) 
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: deep octopus on March 19, 2013, 09:42:32 PM
A rough interpolation/extrapolation of the daily AO index tells me March would average at about -4.3. That's ridiculous and a record shatterer by about an entire point. Slightly off topic, but with the NAO phase also going deeper into the negative, I guess it's going to be another visit from Old Man Winter for much of the Northern Hemisphere? The AO index is about to swing violently positive in the next couple weeks though... So... We should expect to seem some pretty rapid changes to the NH climate patterns soon, I presume? Either way, a traumatic week is ahead for the Arctic, it sounds.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif (http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: werther on March 19, 2013, 09:48:44 PM
In an attempt to get to grips with this winters’ character, I started summarizing/analysing the NCEP/NCAR decadal means for the NH I have collected since September.
Out of SLP, 1000Mb temp ea. I chose the 500Mb samples, assuming they were most significant for the general pattern. With that, I transferred some features to CAD, scaling them to my Polar basic layer.
I marked the axes of the Rossby wave ridges and troughs. I turned the areas with positive and negative height anomaly into measurable polygons.
The result looks like this:
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1036.photobucket.com%2Falbums%2Fa446%2Fhanver1%2FArctic%2520ice%25202013%2FTotal500Mbpositiveanoareawinter1213small_zps0142e89a.jpg&hash=acf1a9a0581390e535c07b0b5d88fca9)
The dotted areas present positive height anomaly during 16 decades. Mind, I didn’t include areas without relevance for the Boreal/Arctic zone (+45dN).
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1036.photobucket.com%2Falbums%2Fa446%2Fhanver1%2FArctic%2520ice%25202013%2FTotal500Mbnegativeanoareawinter1213small_zps8cbad3f1.jpg&hash=e5607bda2c610c77fa469b54d09fe0bb)
This is the counterpart; negative height anomaly of the 500Mb pressure boundary.
What does this illustrate? I feel some embarrassment to think I just showed the total anomaly presented by NCEP/NCAR to be correct. A lot of work, just to find data reliable.
But, in the process, I’ve learned some interesting facts.
(1)   There was never a negative anomaly over Greenland and Davis Strait.
(2)   Negative anomalies occurred most often near Mongolia, the Bay of Biscay and over the  Keewatin region (Canadese Nunavut)
(3)   The ‘crack-site’ Beaufort Sea was usually on the leeward side of the positive anomaly; mean winds had a strong SE component, enhanced by the Keewatin negative anomalies
(4)   It looks like the mean didn’t feature a classic pattern for a ‘Beaufort Gyre’ under cold lower tropospheric high pressure and a persistent vortex high up
(5)   In line with (4), steering patterns were much more elongated (compared to a climatic vortex winter), catching up out of the Pacific and Atlantic with a strong anticyclonic tendency
(6)   The Kara-Barentsz Seas, consequentially, endured a tendency for NE winds, cooling theregion
(7)   Indeed, Greenland was the main pivot in the circulation
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1036.photobucket.com%2Falbums%2Fa446%2Fhanver1%2FArctic%2520ice%25202013%2FTotal500Mbwaveaxes1213small_zps10075d47.jpg&hash=bdd16ece07e6cb23871e5aca211b9224)
This ‘Medusa head’ represents the decadal position of the axes of 72 ridges and 91 troughs between 1 October and 10 March.
In the chaos, I marked three patterns that stand out. It looks like ridges stall preferredly over the Eastern Pacific as well as the Eastern Atlantic. Troughs had an exclusive card for the Hudson/Great Plains region, contributing to the Keewatin negative 500 Mb height anomaly. To lesser extent, that counted for the East Asian region too (cold Manchuria…).
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven on March 19, 2013, 10:01:04 PM
I don't know how to interpret that, but it looks fantastic, Werther!
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: werther on March 19, 2013, 10:43:47 PM
Well Neven,

My wife isn't a politician like you, she thinks the pics look bad...

But generally, the quest gives me an affirmation that patterns did change, and not just to the extent that this is a 'normal' AO-negative winter.
Of course, in the same procedure one should analyse precursing years.
But on advance, I would suggest a lot more heat was transported/collected over the Arctic than in earlier winters.
Second, DO may very well be right in his post above; the arrival of spring could result in a rapid pattern change. The NOAA AO forecast seems to point in that direction...

Third, SIA/SIE, even PIOMAS volume might be delusive. All have picked up through side effects of the weird winter pattern. But the main effect will still be that structural weakness of the pack and 'inefficient' spatial spread of the regrowth show in an amazing decline early this melt season.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: PhilGChapman on March 20, 2013, 01:32:51 AM
This from @NASA_ICE :
First science flight of #IceBridge's 2013 Arctic campaign scheduled for tomorrow. Possible target: sea ice north of Greenland.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on March 20, 2013, 01:46:39 AM
Phil,

Nice find. It would be interesting to hear their findings after the last two day's events.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on March 20, 2013, 10:17:59 AM
Discovery News (http://news.discovery.com/earth/oceans/arctic-storm-fractures-sea-ice-130316.htm) picks up the story, credits A-Team/ASI blog.

Discovery have however seen it fit to delete my helpful comment, which is nonetheless still visible where they auto-posted it to my Facebook page.

http://www.facebook.com/SoulSurfer7 (http://www.facebook.com/SoulSurfer7)

Over here on this this side of the pond the Great British Press have been playing the same game:

http://econnexus.org/the-strange-tale-of-the-mail-and-the-snow-dragon/ (http://econnexus.org/the-strange-tale-of-the-mail-and-the-snow-dragon/)

Meanwhile "The Mirror" is now cracking in the general direction of Nord:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Focean.dmi.dk%2Farctic%2Fimages%2FMODIS%2FMorrisJessup%2Fsmall%2F20130319TERR.small.jpg&hash=32a9059d9d1a27249524a972de3b3a4a)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on March 20, 2013, 03:37:06 PM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Frapidfire.sci.gsfc.nasa.gov%2Fimagery%2Fsubsets%2FArctic_r04c02%2F2013078%2FArctic_r04c02.2013078.terra.1km.jpg&hash=9fb03c46bec5b3cda18b23fc5ed25be1)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Frapidfire.sci.gsfc.nasa.gov%2Fimagery%2Fsubsets%2FArctic_r03c03%2F2013078%2FArctic_r03c03.2013078.terra.1km.jpg&hash=ff1c4b6c4dfd19e0d8b3fffd26c9ad81)

The ice cap just said goodbye to the CA and Greenland. What do we call this? the North by northwest Passage?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Pmt111500 on March 20, 2013, 04:48:39 PM
The Fram express is now a bullet train?

I think it's rather that Svalbard is going to be really cool for a while.  (btw: cool in Swedish is sval and bard is just what it is in englinsh so their name could be translated as 'poet of cold' or ' (physically) cold singer').
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on March 20, 2013, 08:56:59 PM
From Arctic Sea Ice Blog:



Lincoln Sea / Station Nord Greenland:

With almost only half of the remaining "solid" sea ice left in Lincoln Sea, and a small part above Station Nord and this part is gone in a few days, the whole coast line from Banks Island (Canada) to Flade Isblink (Greenland), is free of solid sea ice, I am convinced we can call this a historic moment, and it is only March 20.

Joekelbugt and South;

The amount of solid sea ice is very low too, even compared to recent years, and the sea ice is showing signs of disintegration from above Île de France to Shannon Island in the south.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ritter on March 20, 2013, 09:52:46 PM
.....the whole coast line from Banks Island (Canada) to Flade Isblink (Greenland), is free of solid sea ice, I am convinced we can call this a historic moment, and it is only March 20.
Awesome! In the bad way.  :o
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on March 21, 2013, 02:24:19 PM
Re posted from Arctic Sea Ice Blog:

Station North Greenland and Lincoln Sea,

Heavy sea ice turbulence and cracking is seen north of Station North, this can be watched from the Modis Swath material of today. Further down the North Eastern coast of Greenland, of Joekelbugt and a bit north the fast/solid sea ice is seen disintegrating.

Another big fracture is seen across the remaining (from yesterday) solid Sea Ice in Lincoln Sea.
 
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: deep octopus on March 21, 2013, 02:38:54 PM
CT ice area in the Baffin Bay region is taking a huge hit from the recent "heatwave" over Greenland/Nunavut, just below 900,000 km^2 in actual area, and nearly 300,000 km^2 below average. It was in early May last year when this region previously melted to an area size this low. Spring melt already well underway there, with the sun already beginning to overstay its welcome.

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.4.html (http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.4.html)

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on March 21, 2013, 08:18:07 PM
Reposted from the ASIB, with the latest addendum:

http://econnexus.org/a-new-world-view-from-nasa/ (http://econnexus.org/a-new-world-view-from-nasa/)

The "Fragmentation" has now passed Nord, and is heading down the east coast of Greenland
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on March 21, 2013, 08:39:51 PM
It is already done above.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on March 22, 2013, 01:46:24 PM
Anyone picking up more recent AVHRR imagery from

ftp://cisclient.cis.ec.gc.ca/HRPT-Resolute--ArcticComposite/

or the other associated ftp sites? It seems the buffer filled to 61 images and they are not reclearing it since 032113 1815.

It is a real shame since that has been the highest resolution imagey I have found to follow and at times - post!

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on March 22, 2013, 01:55:07 PM
The latest I could get.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on March 22, 2013, 02:29:33 PM
Anyone picking up more recent AVHRR imagery from

ftp://cisclient.cis.ec.gc.ca/HRPT-Resolute--ArcticComposite/ (http://ftp://cisclient.cis.ec.gc.ca/HRPT-Resolute--ArcticComposite/)

or the other associated ftp sites?

In brief, No! I have the very same problem. Luckily I stumbled upon NASA Worldview a couple of days ago, which is remarkably handy for daily "visible" images:

http://earthdata.nasa.gov/labs/worldview/ (http://earthdata.nasa.gov/labs/worldview/)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Pmt111500 on March 22, 2013, 03:05:40 PM
this not exactly arctic, but there's fragmentation going on elsewhere too, i'd like to suggest this is produced by some internal dynamics of large-enough ice fields once the ice is thin enough and spring starts. Lake Ladoga yesterday:
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on March 23, 2013, 12:17:04 AM
E Canada AVHRR is back online
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Ice Cool Kim on March 24, 2013, 08:17:36 PM
Octopus: "... with the sun already beginning to overstay its welcome"

I suspect if you lived up there you may view things differently after six months of freezing you nuts of.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven on March 24, 2013, 08:23:00 PM
Octopus: "... with the sun already beginning to overstay its welcome"

I suspect if you lived up there you may view things differently after six months of freezing you nuts of.

Except that his remark is in relation to sea ice in Baffin Bay. And I don't think that the Inuit are happy when sea ice starts melting earlier and earlier. Otherwise they'd already be living on the Bahamas.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on March 24, 2013, 11:04:03 PM
Very useful photos of sea ice from Christy's Greenland Blog.
http://hansen-greenland-2013.blogspot.co.uk/ (http://hansen-greenland-2013.blogspot.co.uk/)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: deep octopus on March 25, 2013, 03:55:26 PM
Octopus: "... with the sun already beginning to overstay its welcome"

I suspect if you lived up there you may view things differently after six months of freezing you nuts of.

Except that his remark is in relation to sea ice in Baffin Bay. And I don't think that the Inuit are happy when sea ice starts melting earlier and earlier. Otherwise they'd already be living on the Bahamas.

Thank you, Neven, that was precisely my point.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: lanevn on March 26, 2013, 04:50:36 PM
But why is all this fracture happens if the sea ice have same thickness as in recent years? Something must be wrong - ice thickness measures or this amount of fracture is not so unusual.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: crandles on March 26, 2013, 05:00:58 PM
Just because the volume and area are very similar resulting in similar average thickness calculation doesn't mean the distribution of thicknesses are the same. Indeed we can see differences:

eg
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1340.photobucket.com%2Falbums%2Fo728%2FOlTom67%2FquikSat14Years2_zps09eaefdb.gif&hash=4c0898cd62e356edb4510c670970d285)

Beaufort, East Siberian don't have as much thick/MYI ice.

(Ascat higher resolution (2.5x) radar for 2010-13. Thanks to A-team.)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: lanevn on March 26, 2013, 08:08:01 PM
Hm, in Beaufort really were some MYI in 2012, but along Siberia even thinner ice than now if believe to model http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticict/nowcast/ict2012030118_2012030200_035_arcticict.001.gif (http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticict/nowcast/ict2012030118_2012030200_035_arcticict.001.gif). But in your foto 2013 Siberia looks really darker. So thick model have error? Maybe they just don't want to be alarmists and adding some value to ice ).
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Donald on March 26, 2013, 10:00:34 PM
Also posted this in the blog --

Over the last two days there has been a very noticeable breakup of ice in the Fram Strait.

Compare today, March 26 -- http://earthdata.nasa.gov/labs/worldview/?map=-493632,-1533056,-2112,-1241472&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-26T12:00:00&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=-493632,-1533056,-2112,-1241472&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-26T12:00:00&switch=arctic)

With March 24 -- http://earthdata.nasa.gov/labs/worldview/?map=-493632,-1533056,-2112,-1241472&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-24T12:00:00&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=-493632,-1533056,-2112,-1241472&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-24T12:00:00&switch=arctic)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: crandles on March 26, 2013, 11:58:35 PM
I could well have been wrong to include 'East Siberian' and 'thick' in my last post. I think it may be that these Ascat images show light grey for MYI because/where surface is uneven. Thus the images may not say much about thickness except by the implication that MYI tends to be thicker. Or maybe I am wrong now. Hopefully someone more knowledgeable about interpreting these images will clarify.

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: John Batteen on March 27, 2013, 06:15:22 AM
The cracking has grown dramatically over the last two days.  Anyone else noticing this?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Dromicosuchus on March 27, 2013, 07:02:25 AM
Honestly, John, it's getting hard for me to keep track of it at this point; the fracturing is becoming so extensive that it's difficult to tell what was there before and what's new.  That said, I have noticed a recent crack that's arced out from New Siberia on the Russian side of the Arctic.  I'm not sure whether that's normal or abnormal for this time of the year, though.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on March 27, 2013, 09:09:50 PM
Latest from Env Can.
https://docs.google.com/file/d/0B3pB-kdzoLU3b3VzTHpNRFNVSDQ/edit?usp=sharing

 :o
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Juan C. García on March 27, 2013, 10:43:39 PM
Some polynyas that are showed from AMSR2 (Bremen):
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1275.photobucket.com%2Falbums%2Fy449%2Fjuancgarcia22%2FNSIDC_DailyValuesAvg%2FPolynyas_march_zps7c03947d.jpg&hash=923e118558181e3f26b3b724c99cb893)
It is too early, isn't it? And at several places of the Arctic...
http://www.iup.uni-bremen.de:8084/amsr2/ (http://www.iup.uni-bremen.de:8084/amsr2/)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on March 28, 2013, 02:48:15 AM
For a close up view of the "Banks Island Polynia" see also:

http://econnexus.org/bigger-cracks-than-ever-in-the-beaufort-sea-ice/ (http://econnexus.org/bigger-cracks-than-ever-in-the-beaufort-sea-ice/)

It is too early!
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: crandles on March 28, 2013, 12:20:56 PM
http://lance-modis.eosdis.nasa.gov/imagery/subsets/?mosaic=Arctic.2013086.terra.367.4km (http://lance-modis.eosdis.nasa.gov/imagery/subsets/?mosaic=Arctic.2013086.terra.367.4km)

Has to be really dark and not just red to be open water. (Or white cloud over really dark area.)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on March 28, 2013, 02:22:06 PM
It would seem to pass the "A-Team test", on the 26th at least?



Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on March 28, 2013, 06:52:25 PM
I think that Polynya probably was open water.

However in the true colour MODIS for yesterday, 250m resolution, the open water is ice covered.
http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r04c02.2013086.terra.250m (http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r04c02.2013086.terra.250m)

And in yesterday's IR that I posted above there is what looks like a large amount of low warm cloud/fog streaming from the polynya.
https://docs.google.com/file/d/0B3pB-kdzoLU3b3VzTHpNRFNVSDQ/edit?usp=sharing (https://docs.google.com/file/d/0B3pB-kdzoLU3b3VzTHpNRFNVSDQ/edit?usp=sharing)
URL corrected.

The latest IR suggests a reduction of this humidity flux.
http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg (http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg)

Regional pressure fields suggest that winds would be from Banks into the Arctic, supporting my interpretation of a moisture plume.
http://www.wetterzentrale.de/topkarten/fsavnnh.html (http://www.wetterzentrale.de/topkarten/fsavnnh.html)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: HeisenIceBerg on March 28, 2013, 07:07:44 PM
Looks like a pretty long crack has opened up over the past two days just east (above in Worldview) of the islands separating the Laptev and Kara Seas.  No crack visible through the clouds on the 26th, first noticeable on the 27th, and wider on the 28th.

Mar 27: http://earthdata.nasa.gov/labs/worldview/?map=486752,-53312,1885536,575424&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-27T12:00:00&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=486752,-53312,1885536,575424&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-27T12:00:00&switch=arctic)

Mar 28: http://earthdata.nasa.gov/labs/worldview/?map=486752,-40000,1885536,562112&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-28T12:00:00&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=486752,-40000,1885536,562112&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-03-28T12:00:00&switch=arctic)

Also, correct me if I'm mistaken, but it looks like the ice just west of the islands (below in Worldview) is younger, thinner ice.

One last thing.  Chris, I'm not sure if this is just for me or if others are experiencing this, but I can't access the docs.google.com links that you've posted.  I get the message,

"You need permission to access this item.

You are signed in as [my google account email], but you don't have permission to access this item. You can request access from the owner or choose a different account."
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on March 28, 2013, 07:10:46 PM
Heisenberg,

Fixed now, just in case the URL has changed here it is.
https://docs.google.com/file/d/0B3pB-kdzoLU3b3VzTHpNRFNVSDQ/edit?usp=sharing
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: frankendoodle on March 30, 2013, 01:05:32 AM
If nothing else, these fissures illustrate just how thin to non-existent the ice sheet is on the Eurasian side.  It reminds me of all the fissures last summer just before the great arctic hurricane of 2012. (I'm not implying that a storm like that is going to happen now)
http://ice-glaces.ec.gc.ca/prods/MODISCOM-F/20120806000000_MODISCOM-F_0006580948.jpg (http://ice-glaces.ec.gc.ca/prods/MODISCOM-F/20120806000000_MODISCOM-F_0006580948.jpg)

I don't think these cracks will have any impact on the summer melt. I think they show just how susceptible the ice sheet is to currents now that it is mostly first year ice.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on March 30, 2013, 05:42:07 AM
Nasa Earth Observatory has just put up a new report on the Beaufort Sea Ice Collapse. Interesting to see Meier's comments.

http://earthobservatory.nasa.gov/IOTD/view.php?id=80752 (http://earthobservatory.nasa.gov/IOTD/view.php?id=80752)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: sofouuk on March 30, 2013, 09:28:51 AM
also interesting to see nasa routinely linking to neven!  :P
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Sigmetnow on March 31, 2013, 12:27:03 AM
I’ve been practicing my animations....  Here are views of North East Greenland ice as it fractures and moves south.  Just 5 pics (to keep file size down), between Feb 24 and March 22, 2013.  I’ve set them to run rather slowly.  Note the (temporary) refreeze on the two concave sections.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: TerryM on March 31, 2013, 07:25:17 PM
Arctic.io has his Split Zoom feature up and running. This is the most accurate as well as the easiest method of comparing change over time of Arctic ice during the melt season.


I won't get into the details here, but urge everyone to try it out. The learning curve is short to nonexistent & the results are spectacular. It shows two MODIS images side by side that can be zoomed smoothly. Comparing small movements from one date to another is easy since the pointer on each screen is in exactly the same position.


There's nothing on the internet like this & anyone following glacial movements, fracture development or looking for changes in fast ice will find it invaluable.


Terry
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on March 31, 2013, 10:16:23 PM
Terry,

Seconded.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: frankendoodle on March 31, 2013, 11:18:31 PM
I was just looking at the cracks in the Beaufort Sea ice sheet while watching a NASA animation posted on arctic.io when it struck me that the Beaufort Sea was the area that melted first and  the fastest last summer. It also reached temperatures exceeding 15 C  near the Canadian coast. I remember relatively minor cracks NW of the Canadian Archipelago last May, but nothing like this year. 
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on April 02, 2013, 04:08:57 AM
I expect further fragmentation and breakup in to smaller floes in the next week, and more fracturing on the Russian and Canadian Arctic areas. Attached is the CICE movement for April 6 2013 as an illustration.

Even if we go to a positive anomaly, I suggest the motion will continue.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on April 02, 2013, 03:03:38 PM
Furthermore, fracturing continues to redevelop, and breakup the ice into smaller sections.

When melt season finally arrives both the Beaufort and areas north of Ellesmere will be more mobile and vulnerable.

The AVHRR imagery is from April 2, 2013.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on April 04, 2013, 03:19:17 PM
A-Team and Sigmetnow:

Today April 4:
Pre-Fractures are now clearly seen into the CAA from the north, between Ellesmere ; Ellef Ringnes and Banks Island.

I am sure we will soon need some animators to cover this story
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Williams on April 04, 2013, 05:34:59 PM
It there any actual data on Ice thickness this Spring?  (I'll leave it at that and not speculate on Models which have been doing fairly well.)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: deep octopus on April 04, 2013, 05:52:59 PM
Espen, I was beginning to notice that same thing as well. And the wounds north of Ellesmere have been trying to punch through once again, as of yesterday. In a few more hours, we should see if this has significantly changed.
http://earthdata.nasa.gov/labs/worldview/?map=-1189152.9140625,-189523.3046875,-464160.9140625,198060.6953125&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-04-03T12:00:00&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=-1189152.9140625,-189523.3046875,-464160.9140625,198060.6953125&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-04-03T12:00:00&switch=arctic)

Also, the ice pack north of Ellesmere/CAA in general is clearly moving in the clockwise/westward direction, comparing April 2nd with April 3rd, now that the clouds have moved away for now. This is looking like a very loose tooth, I fear.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on April 04, 2013, 06:40:36 PM
Deep Octopus;

Yes the fraction-action is not over yet!
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on April 04, 2013, 10:35:45 PM
The pre-fracs into northern CAA are now seen in the Modis too, when scrutinized:

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r04c02.2013094.aqua.250m (http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r04c02.2013094.aqua.250m)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Sigmetnow on April 05, 2013, 02:18:02 AM
Here’s north and northeast of Banks Island, on April 1 and April 2, 2013.  This is from www.arctic.io (http://www.arctic.io) > Sea Ice > Split Zooms.  (Thanks, Terry!)  Please ignore the red arrow.

Is the wider appearance of the major cracks on April 2 mostly due to clouds from water vapor coming off open water in the cracks?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: TerryM on April 05, 2013, 07:47:14 AM
sigmetnow


Save the thanks for Arcticio, he posts here regularly and has put an unbelievable amount of work into his sight. I much prefer his method of moving around in MODIS & as I mentioned, and you now know, there is no better way of checking for small shifts in Arctic ice than his split zoom.


Come melt season I spend hours there checking fjords, fast ice, melt ponds & any other things that have caught my attention. The split zoom feature is quite new (end of last season) and still has problems from time to time - but when it's up it's totally unreal.


Terry
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Sigmetnow on April 05, 2013, 02:48:49 PM
Well then, Terry:  Thanks for the info and link to arctic.io !  It does indeed have a bunch of good stuff to go through.  There goes another chunk of my spare time!
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Sigmetnow on April 07, 2013, 02:52:09 PM
This Huffington Post article has an excellent video animation of the Beaufort Sea Ice Fracturing, plus several beautiful glacier and “Climate Change” photos, and a some interesting Arctic Sea Ice news videos.

http://www.huffingtonpost.ca/2013/04/04/beaufort-sea-ice-fracture-video_n_3015085.html (http://www.huffingtonpost.ca/2013/04/04/beaufort-sea-ice-fracture-video_n_3015085.html)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on April 14, 2013, 04:56:26 PM
We have been engaged in a conversation about whether the fragmentation event will impact summer melt season.

One question has been whether the ice would be more mobile, in other words, if additional motion of fractured ice would lead to additional melt.

Another question has been whether the NP would be ice free this year.

HYCOM/CICE may be providing additional weight to "yes" answers to both questions.

What follows are HYCOM/CICE  calculations from Jan 1, Mar 1, April 1, and April 21.

Note the fracturing events and the subsequent ice motion into the Beaufort and away from 90 N.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: SCYetti on April 15, 2013, 12:53:50 AM
In reading this discussion I've had the thought that the Arctic could possibly be ice free this year because of the fragmentation event since February. This is due to the increased speed of the Arctic Drift and the Beaufort Gyre. A-Team's visualisation of movement in the gyre showed 479 km movement in less than 6 weeks. This shows extraordinary thinness and weakness of the ice that not only makes it more susceptible to melt but also to being flushed into the Atlantic.

In order to contribute more than my opinion; I found this article that discusses ice speed and thickness and how lack of consideration these relate to the inadequacies of Arctic Models.

http://web.mit.edu/~rampal/rampal_homepage/Publications_files/Rampal2011_J.%20Geophys.%20Res.pdf (http://web.mit.edu/~rampal/rampal_homepage/Publications_files/Rampal2011_J.%20Geophys.%20Res.pdf)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on April 18, 2013, 03:28:58 AM
NASA has put up a new Youtube video in regard to Arctic Sea Ice maximum and the fracturing.

While helpful, it does not address all of the issues of this winter's ice behavior.

Arctic Sea Ice Max 2013: An Interesting Year (http://www.youtube.com/watch?v=K5Ni_6ntZ3Q#ws)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Donna on April 18, 2013, 04:06:54 AM
While helpful, it does not address all of the issues of this winter's ice behavior.

Arctic Sea Ice Max 2013: An Interesting Year (http://www.youtube.com/watch?v=K5Ni_6ntZ3Q#ws)
 

From the video "...where we might see virtually ice free summers in the arctic in just a few decades." 

I wish I were that optimistic.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on April 19, 2013, 12:34:20 AM
Is it possible that a fragmentation event could actually benefit the sea ice and could ice breakers do so early enough in proper weather?

Are there any good studies on sea ice losing it's salinity?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: crandles on April 19, 2013, 12:53:45 AM
Fragmentation is likely causing increased ice ridging elsewhere an increase in ice volume. I doubt we would be likely to have enough ice breakers to have significant effect. It is likely that effect in fall/winter is to increase volume but use in spring and summer decreases albedo and leads to more heat absorption within the pack.

More icebreakers would probably mean more use in spring rather than mainly in fall & winter so probably not beneficial.

Miles travelled would be small compared to all those cracks we have seen.

Was there a link with salinity?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on April 19, 2013, 01:13:31 AM
Fragmentation is likely causing increased ice ridging elsewhere an increase in ice volume. I doubt we would be likely to have enough ice breakers to have significant effect. It is likely that effect in fall/winter is to increase volume but use in spring and summer decreases albedo and leads to more heat absorption within the pack.

More icebreakers would probably mean more use in spring rather than mainly in fall & winter so probably not beneficial.

Miles travelled would be small compared to all those cracks we have seen.

Was there a link with salinity?

I figured a fragmentation event would have to be early to strengthen the sea ice, but it could cause the sea ice to resist being melted to ice free conditions and it could be used to make sea ice with ice breakers. I thought the Russians were building them anticipating a new trade route.

The sea ice has to lose it's salinity to strengthen, so I was wondering how fast it can lose salinity. I recall cases where antarctic sea ice was strengthened because too much snow cover caused it to crack and sink and the sea water froze turning snow to ice.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: crandles on April 19, 2013, 01:53:44 AM
I don't imagine fragmentation doing anything but weaken the ice. There is likely somewhere else where ridging is thickening ice. So the extra volume is elsewhere. The new ice forming in cracks is likely formed fast and therefore salty and new.

To lose salinity you really want temperature changes to cause salty parts of the ice to melt and drain then refreeze then melt different salty parts of the ice and keep repeating. Lower latitudes that get bigger differences in sun angle may be more suitable location. Probably lots of references on brine rejection.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Juan C. García on April 19, 2013, 07:06:16 AM
This area has a crack that has stayed for the whole April. From my point of view is growing, becoming wider than before. I don’t remember seeing something like this in the past. The Arctic sea ice is very weak.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi1275.photobucket.com%2Falbums%2Fy449%2Fjuancgarcia22%2FNSIDC_DailyValuesAvg%2FCopiadeBremen_AMSR2_Color_130418_zps970e1b10.jpg&hash=063fc3baacb4f29249a46ab9e128038c) (http://s1275.photobucket.com/user/juancgarcia22/media/NSIDC_DailyValuesAvg/CopiadeBremen_AMSR2_Color_130418_zps970e1b10.jpg.html)

http://www.iup.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.png (http://www.iup.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.png)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: wanderer on April 19, 2013, 10:22:13 AM
It's easy to watch with Worldview:
http://earthdata.nasa.gov/labs/worldview/?map=-2307040,-1098304,2690080,3218880&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-04-19&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=-2307040,-1098304,2690080,3218880&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-04-19&switch=arctic)

Compare it to May 2012 - a similar cracking is visible.
On May 8th (when records started in 2012) we will see how big the difference is.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on April 19, 2013, 03:42:48 PM
Juan's crack has been opening/freezing for many weeks, just like those over in the Beaufort, where you can see the "Wrangel end" of it:

http://econnexus.org/beaufort-sea-ice-cracks-once-more/ (http://econnexus.org/beaufort-sea-ice-cracks-once-more/)

Also just like those, it's briefly "reopened" recently. Whether any of them "stay open" this early in the year is "the 64 trillion dollar question"!
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on April 19, 2013, 04:48:48 PM
It's easy to watch with Worldview:
http://earthdata.nasa.gov/labs/worldview/?map=-2307040,-1098304,2690080,3218880&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-04-19&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=-2307040,-1098304,2690080,3218880&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-04-19&switch=arctic)

Compare it to May 2012 - a similar cracking is visible.
On May 8th (when records started in 2012) we will see how big the difference is.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Frapidfire.sci.gsfc.nasa.gov%2Fimagery%2Fsubsets%2F%3Fmosaic%3DArctic.2012109.terra.4km.jpg&hash=3c5f57ee3c0764a9d614175414a997be)
http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2012109.terra.4km.jpg (http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2012109.terra.4km.jpg)

Earlier images are available direct from NASA LANCE-MODIS

The 2012109 in the address is the year/julian day. Change it to whatever you want to see.


V
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on April 19, 2013, 09:09:22 PM
Juan,

That's a coastal flaw lead. It normally follows the coast but at present moves into the pack around a region of thicker compacted land fast ice that was subjected to compression and ridging during the February/March fracturing event.

PIOMAS shows it as being a thick region of ice.
http://farm9.staticflickr.com/8523/8639697147_140715b595_o.png (http://farm9.staticflickr.com/8523/8639697147_140715b595_o.png)

It can be seen in the following graphic which shows net ice movement between 19 Feb and 5 March.
http://farm9.staticflickr.com/8248/8534579476_7aa84d8919_o.gif (http://farm9.staticflickr.com/8248/8534579476_7aa84d8919_o.gif)

ASCAT shows that while the net movement is rather more complex than in the fracturing event there is a consistent movement away from the Siberian coast, which in this case is the edge of the landfast ice pack. This is the typical winter state, where the transpolar drift draws ice away from Siberia and towards the CAA and Fram outflow, with new ice forming in the leads created by the Siberian divergence.

The area of this lead may represent the region where the melt starts in June, however despite compression and ridging the Siberian landfast ice won't last much into June.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Juan C. García on April 20, 2013, 08:01:58 AM
Thanks Wanderer, Jim, Vergent and Cris from your answers.
I think that we will have to wait a couple of weeks to see how the crack will develop, but at this moment, I believe that the fragmentation event will be a topic on April/May and it will have an important impact in this melting season.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Yuha on April 21, 2013, 05:49:30 AM
ASCAT shows that while the net movement is rather more complex than in the fracturing event there is a consistent movement away from the Siberian coast

There has also been consistent movement of MYI towards Beaufort Sea squeezing FYI against the coast. That MYI and compressed FYI might delay the melt there. At least the very early melt that looked likely after the fracturing event is now less likely.

Of course, the winds may turn and change the situation again.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on April 21, 2013, 07:52:30 AM
Yuha,

The MYI has partly moved into Beaufort, but I still think the extent is less than normal. Then we have the leads which will open up in the fractures that opened in Feb/Mar. I still expect rather an aggressive melt in Beaufort.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven on April 21, 2013, 11:47:20 AM
I still expect rather an aggressive melt in Beaufort.

I'm rather certain of it. I believe last year's cracking event had started around this time, so it's just a matter of the right winds to tear things apart.

I believe I'm already seeing some patches of open water north of Barrow on yesterday's satellite image (http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r05c03.2013110.terra).

But conditions will remain cloudy for some time to come. Maybe that could slow things down.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on April 21, 2013, 02:31:07 PM
Juan's "coastal flaw lead" grows ever wider:

http://econnexus.org/has-the-laptev-sea-started-melting/ (http://econnexus.org/has-the-laptev-sea-started-melting/)

Will that trend continue, do you suppose?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Whit on April 21, 2013, 05:07:15 PM
Comparing this years ice to last years it seems that this years ice in the cracked up areas are of a different quality. I don't think everything can be attributed to thickness alone.

In several areas in for instance The Beaufort and Chuckchi-seas, the cracks last year were more angular and seemed to "fit better" in the pattern left after the cracking events.

This year the cracked areas have several patterns where the floes seem more rounded and the cracks seem messier.

Based on this I would say the ice in the cracked areas generally is softer and more prone to crumbling than it was on May 8th 2012. It's a general impression I get just by comparing images in eos worldview.

Granular uneven cracks and varying floe-sizes (2013) vs. angular even cracks with more uniform floe-sizes (2012), might be one way of expressing what I'm thinking about.

Has anyone else got the same impression?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Sigmetnow on April 22, 2013, 12:33:55 AM
Back in the Beaufort Sea, there have been lots of clouds over the main ice pack, but the Navy HYCOM ice thickness graphics suggest significant fracturing and movement south is occurring.  Here’s April 1 to April 20 (missing April 16).
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on April 22, 2013, 04:47:03 PM
There's cracks wherever you look these days. The full HYCOM/CICE shows the Laptev Sea ones opening up, though they now seem to refreezing.

In the meantime here's some new ones in the Nord area:
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on April 22, 2013, 06:32:37 PM
P.S. The US Navy are forecasting some more long cracks in the near future. This closeup is for the 28th.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: johnm33 on April 24, 2013, 11:20:48 PM
Looking here http://polar.ncep.noaa.gov/seaice/nh.html (http://polar.ncep.noaa.gov/seaice/nh.html) and going through the animation step by step it's arguable that atlantic waters have reached through to barrow probable cause of Juans crack on the way, but with the full moon giving higher tides and this fresh source of heat we could be in for a very interesting week in the Canadian arctic.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on April 26, 2013, 01:22:14 AM
And now there's plenty of open water in the Chukchi Sea:

Worldview's take (http://earthdata.nasa.gov/labs/worldview/?map=-756768,2240192,71136,2734272&products=baselayers,MODIS_Aqua_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-04-25&switch=arctic)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Sigmetnow on April 29, 2013, 03:00:54 PM
Wow -- extensive fractures visible north of CAA today.

http://earthdata.nasa.gov/labs/worldview/?map=-1257600,-35200,-115840,833152&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-04-28&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=-1257600,-35200,-115840,833152&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-04-28&switch=arctic)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on April 29, 2013, 06:18:59 PM
Sigmetnow;

Yes it looks like a close up of nylon stockings, with all this melt surface this ice will disappear at record time.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: slow wing on April 29, 2013, 11:59:53 PM
Is it unusual for this time of year?


Here is the corresponding image for last year - though a few days later, 8 May, as that is the first date available...
http://earthdata.nasa.gov/labs/worldview/?map=-1257600,-35200,-115840,833152&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2012-05-08&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=-1257600,-35200,-115840,833152&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2012-05-08&switch=arctic)

The ice in the 2012 image looks more broken up to me.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Sigmetnow on April 30, 2013, 10:33:12 PM
Is it unusual for this time of year?
...
The ice in the 2012 image looks more broken up to me.

slow wing,

Perhaps.

But with, for example, the major ice drift this winter, the early Feb-March fracturing event(s) -- and a record amount of early melting, documented this week in the Forum’s CTA April Poll thread -- an Arctic Situation that is worse today than last year seems quite likely.  So we watch for clues.

While it may not offer proof one way or the other, my point was that the image is striking. 
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on May 02, 2013, 01:51:10 PM
The Chukchi froze over again. Some of the Laptev polynyas have opened again. Things seem to have started melting in earnest in what we should perhaps now call the Far North Atlantic?

Meanwhile the clouds have cleared from the east coast of Baffin Island to reveal this:

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: johnm33 on May 02, 2013, 03:09:28 PM
There's a low to the west and a high to the east pushing that lot northeast, and with the high in the pacific I'm guessing that's why the Atlantic water is backing up near the pole causing the thinning there, which I think hints it's close to the surface.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on May 02, 2013, 10:47:51 PM
And this lot's opened up since yesterday, around Kap Morris Jesup:

Image courtesy of Worldview (http://earthdata.nasa.gov/labs/worldview/?map=-561971.677327,-739150.76495,-121395.677327,-480334.76495&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-05-02&switch=arctic)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on May 13, 2013, 06:47:29 PM
A very heavy crack is showing up between Amundsen Gulf (Beaufort Sea) and Ellesmere right now, and several cracks parallel to that :

http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013133131000-2013133131500.2km.jpg (http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013133131000-2013133131500.2km.jpg)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on May 13, 2013, 06:55:07 PM
Espen,

Coastal Flaw Lead.

Low pressure over Alaska due to move over Beaufort drawing strong winds offshore driving the ice away from the coast.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Pettit on May 14, 2013, 01:27:12 AM
A very heavy crack is showing up between Amundsen Gulf (Beaufort Sea) and Ellesmere right now, and several cracks parallel to that :

http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013133131000-2013133131500.2km.jpg (http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013133131000-2013133131500.2km.jpg)

It's a big 'un, well over a thousand kilometers in length. Impressive. The full picture:

http://lance-modis.eosdis.nasa.gov/imagery/subsets/?mosaic=Arctic (http://lance-modis.eosdis.nasa.gov/imagery/subsets/?mosaic=Arctic)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: wanderer on May 14, 2013, 09:31:29 AM
Yes, but switch to 2012, same spot!
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on May 14, 2013, 09:46:29 AM
Wanderer;

I am aware of that crack/opening from 2012 the big difference is this one goes all the way across Ellesmere Island, and what it misses of open water is leveled of by the Siberian opening.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Whit on May 14, 2013, 09:51:23 AM
Pretty soon we should start to get the answer to what role the cracking events this winter will play. I have a feeling they will be a major player. The cracks are weaknesses, and have generally lower albedo than solid ice. We should see the old cracks opening up again. And in some areas there are a lot more of them than we can see at the moment.

Snapshot near the Pole, May 16th 2012. (http://earthdata.nasa.gov/labs/worldview/?map=-696996.596494,979968,-351140.596494,1174528&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2012-05-16&switch=arctic)

Same area, May 14th 2013. (http://earthdata.nasa.gov/labs/worldview/?map=-696996.596494,979968,-351140.596494,1174528&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines&time=2013-05-14&switch=arctic)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Gray-Wolf on May 14, 2013, 02:05:31 PM
I'd not considered the albedo impacts? with much of the ice cemented together by young ice once melting begins in earnest will we not see a dramatic drop in albedo of the central pack (normally pretty high albedo for contiguous ice?)?

The other thing that comes with a very fragmented pack is a lessening of the dampening from swells. will this lead to more overwash and edge melt over the early season?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Whit on May 14, 2013, 03:03:10 PM
I'd not considered the albedo impacts? with much of the ice cemented together by young ice once melting begins in earnest will we not see a dramatic drop in albedo of the central pack (normally pretty high albedo for contiguous ice?)?

The other thing that comes with a very fragmented pack is a lessening of the dampening from swells. will this lead to more overwash and edge melt over the early season?
The albedo-impacts from refrozen cracks are clearly visible from space, so I suspect they will play a part as insolation increases. I am wondering what it does for melt-pond formation.

When it comes to your second paragraph, my experience with ice is that once you get to a certain stage of fragmentation it all just disappears really fast, at least partially for the reasons you mentioned. There is also the issue of volume vs. surface area that needs to be considered.

Whether we are close to the disintegration-stage now is a completely different question and I'm not competent to answer it. However, a visible inspection can say a fair bit about ice-quality, and it seems to be decreasing year for year. Additionally, if the porosity increases as the thickness decreases we are in for rapid change.

All IMHO.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on May 14, 2013, 03:34:04 PM
Interesting video from Weather.com by Jeff Masters addressing the potential melt and impllications:

http://bcove.me/obq3kp72 (http://bcove.me/obq3kp72)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger on May 15, 2013, 05:47:09 AM
Espen,

Coastal Flaw Lead.

Low pressure over Alaska due to move over Beaufort drawing strong winds offshore driving the ice away from the coast.

Also occurred on the day of the New Moon. The coastal fast-ice usually breaks of on the Spring tide.

Again, we have to be looking for horizontal displacement of the pack ice. This MYI will not all melt in place. But if it is advected South to the Beaufort sea, then see'ya!  :o
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on May 15, 2013, 09:11:11 PM
As ASCAT shows, a lot of it has been transported to Beaufort.

001 2013
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013001.sir.gif (http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013001.sir.gif)

134 2013
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013134.sir.gif (http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013134.sir.gif)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Espen on May 16, 2013, 04:28:10 PM
The crack is now reaching from Amundsen Gulf ( Beaufort Sea) all the way to Flade Isblink ( North East Greeland ): http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013136102500-2013136103000.4km.jpg (http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2013136102500-2013136103000.4km.jpg)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Siffy on May 16, 2013, 05:36:41 PM
As ASCAT shows, a lot of it has been transported to Beaufort.

001 2013
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013001.sir.gif (http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013001.sir.gif)

134 2013
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013134.sir.gif (http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013134.sir.gif)

out interest how much volume and extent is being shown to have pushed out Beaufort?

I'm sadly only an interested layman in terms of understanding.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on May 16, 2013, 06:42:53 PM
Siffy,

I don't know, all I can do is point to a qualitative argument. I've not got ImageJ on my laptop at the moment, I think that might be able to help work out the area/extent.

As for volume. PIOMAS doesn't differentiate between first-year and multi-year. I have to use thickness as a rough proxy for that, and since 2010 the thicker ice hasn't been at such volumes that it makes the multi-year ice stand out. What we have from PIOMAS is the average grid box thickness (actually 'effective thickness'), a grid box may contain some older thicker ice and some younger thinner ice.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Steve Bloom on May 17, 2013, 12:39:34 AM
http://onlinelibrary.wiley.com/doi/10.1002/jgrc.20191/abstract (http://onlinelibrary.wiley.com/doi/10.1002/jgrc.20191/abstract) may have been posted elsewhere already, but I didn't see it and this topic seems like a suitable place.  Title/abstract:

"Arctic sea ice circulation and drift speed: Decadal trends and ocean currents

"We examine the basinwide trends in sea ice circulation and drift speed and highlight the
changes between 1982 and 2009 in connection to regional winds, multiyear sea ice
coverage, ice export, and the thinning of the ice cover. The polarity of the Arctic Oscillation
(AO) is used as a backdrop for summarizing the variance and shifts in decadal drift patterns.
The 28-year circulation fields show a net strengthening of the Beaufort Gyre and the
Transpolar Drift, especially during the last decade. The imprint of the arctic dipole anomaly
on the mean summer circulation is evident (2001–2009) and enhances summer ice area export
at the Fram Strait. Between 2001 and 2009, the large spatially averaged trends in drift speeds
(winter: +23.6%/decade, summer: +17.7%/decade) are not explained by the much smaller
trends in wind speeds (winter: 1.46%/decade, summer: -3.42%/decade). Notably, positive
trends in drift speed are found in regions with reduced multiyear sea ice coverage. Over 90%
of the Arctic Ocean has positive trends in drift speed and negative trends in multiyear sea ice
coverage. The increased responsiveness of ice drift to geostrophic wind is consistent with a
thinner and weaker seasonal ice cover and suggests large-scale changes in the air-ice-ocean
momentum balance. The retrieved mean ocean current field from decadal-scale average ice
motion captures a steady drift from Siberia to the Fram Strait, an inflow north of the Bering
Strait, and a westward drift along coastal Alaska. This mean current is comparable to
geostrophic currents from satellite-derived dynamic topography."

So it's all speeding up, further setting the stage for a quick exit.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Bob Wallace on May 17, 2013, 02:15:21 AM
If you hit "Quote" on Steve's post you'll be able to see a correctly formatted version of the paper summary.

A summary of the summary - transport speed has been increasing and it's likely because the ice is thinner.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Steve Bloom on May 17, 2013, 03:00:04 AM
If you hit "Quote" on Steve's post you'll be able to see a correctly formatted version of the paper summary.

A summary of the summary - transport speed has been increasing and it's likely because the ice is thinner.

Hmm, it looks fine to me as is, Bob.  Browser difference?

And just to be clear, currents have sped up in addition to the ice.  Even if the former had not, it appears that the thinning would have resulted in the latter doing so anyway (albeit not as much).
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Bob Wallace on May 17, 2013, 06:30:47 AM
Chrome.

The line 'returns' are too long for the space.  I get a long line and then a couple of word in the next line.  Then another long line, etc.

"We examine the basinwide trends in sea ice circulation and drift speed
and highlight the
changes between 1982 and 2009 in connection to regional winds,
multiyear sea ice
coverage, ice export, and the thinning of the ice cover. The polarity of
the Arctic Oscillation

I've run into this problem when copying from some sites.  The workaround seems to be "Paste as plain text".  That strips out the formatting.

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: wili on May 17, 2013, 02:56:35 PM
The format was fine for me, too.

What accounts for the increase in the speeds of the currents? Does this further support the idea that more warm Atlantic water is getting into the Arctic?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on May 17, 2013, 06:32:41 PM
The format was fine for me, too.

What accounts for the increase in the speeds of the currents? Does this further support the idea that more warm Atlantic water is getting into the Arctic?

No, it's got nothing to do with it. To quote from the abstract (which formats OK in IE)....

The 28-year circulation fields show a net strengthening of the Beaufort Gyre and the Transpolar Drift, especially during the last decade. The imprint of the arctic dipole anomaly on the mean summer circulation is evident (2001–2009) and enhances summer ice area export at the Fram Strait.


So the wind driven features are strengthening.

Between 2001 and 2009, the large spatially averaged trends in drift speeds (winter: +23.6%/decade, summer: +17.7%/decade) are not explained by the much smaller trends in wind speeds (winter: 1.46%/decade, summer: -3.42%/decade).


But changes in wind speed are not causing the increased ice transport. So what is?

Notably, positive trends in drift speed are found in regions with reduced multiyear sea ice coverage. Over 90% of the Arctic Ocean has positive trends in drift speed and negative trends in multiyear sea ice coverage. The increased responsiveness of ice drift to geostrophic wind is consistent with a thinner and weaker seasonal ice cover and suggests large-scale changes in the air-ice-ocean momentum balance.

The final clear out of MYI, after decades of thinning, seems to be creating thinner, less massive (in the sense of mass of ice per square metre) ice cover. This means that it's easier for the wind to drive the movement of ice.

This looks like another job for HeisenIceBerg...  8)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: wili on May 17, 2013, 06:36:45 PM
Thanks for the clarification, Chris.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Bob Wallace on May 17, 2013, 07:57:10 PM
A summary of the summary - transport speed has been increasing and it's likely because the ice is thinner.

 ;)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: frankendoodle on May 17, 2013, 11:08:07 PM
Not only does the crack run from the northern mouth of the Nares Strait to the Chukchi Sea, but you can make it our on the AMRS2 map.
http://iup.physik.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.pn (http://iup.physik.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.pn)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on May 23, 2013, 05:37:37 PM
The Barents Observer reports (http://barentsobserver.com/en/arctic/2013/05/floating-research-station-need-evacuation-23-05) that the Russian research station "North Pole 40 (http://www.aari.ru/resources/d0014/np40/default.asp?lang=0)" is in trouble:

Russia has ordered the urgent evacuation of the 16-strong crew of a drifting Arctic research station after ice floe that hosts the floating laboratory began to disintegrate, officials said.

The current position of NP40 is 81.7 N, 134.7 W
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ritter on May 23, 2013, 06:26:00 PM
The Barents Observer reports (http://barentsobserver.com/en/arctic/2013/05/floating-research-station-need-evacuation-23-05) that the Russian research station "North Pole 40 (http://www.aari.ru/resources/d0014/np40/default.asp?lang=0)" is in trouble:
The scientific research station was placed on the ice floe in October 2012 and was planned to stay there until September. Now the floe has already started to break apart and the crew has to be evacuated as soon as possible.

My emphasis. Looks like some areas are 4 months ahead of melt schedule!  :o
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ivica on May 23, 2013, 06:35:55 PM
The Barents Observer reports (http://barentsobserver.com/en/arctic/2013/05/floating-research-station-need-evacuation-23-05) that the Russian research station "North Pole 40 (http://www.aari.ru/resources/d0014/np40/default.asp?lang=0)" is in trouble: ...
Donskoy suggests that the nuclear-powered icebreaker “Yamal” could evacuate the station from the floe and move it to Severnaya Zemlya.
Curent position (http://www.marinetraffic.com/ais/shipdetails.aspx?mmsi=273132400) of Yamal (http://en.wikipedia.org/wiki/Yamal_%28icebreaker%29) is unknown (to us). Hurry guys:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fimagevat.com%2Fuploads%2F12292009%2F680978547.jpg.jpg&hash=1c1efe2558e0f94f479e149f415da19f)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on May 23, 2013, 06:53:21 PM
Curent position of  Yamal is unknown (to us). Hurry guys

According to SailWX (http://sailwx.info/shiptrack/shipposition.phtml?call=UCJT) however, Yamal's position at 2013-May-23 06:00 was N 76°06' E 068°18'

A long way to go at the current average speed of 1.0 knots!
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ghoti on May 23, 2013, 07:26:04 PM
Buoy 2012G is colocated with the station.

http://imb.crrel.usace.army.mil/2012G.htm (http://imb.crrel.usace.army.mil/2012G.htm)

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ivica on May 23, 2013, 08:24:37 PM
however, Yamal's position at 2013-May-23 06:00 was N 76°06' E 068°18'
Bravo Jim,
maybe current position is not too bad ...
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven on May 23, 2013, 10:02:59 PM
There's now a blog post (http://neven1.typepad.com/blog/2013/05/russia-abandoning-ice-station.html) on the ASIB concerning NP-40 as well.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Laurent on May 26, 2013, 01:56:28 PM
The Yamal does not seem to go for a rescue!?
http://sailwx.info/shiptrack/shipposition.phtml?call=UCJT (http://sailwx.info/shiptrack/shipposition.phtml?call=UCJT)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on May 26, 2013, 03:11:41 PM
The Yamal does not seem to go for a rescue!?

That's because, according to Russia Today (http://rt.com/news/russia-evacuates-polar-station-708/) at least, it's not due to set off on its "rescue mission" until the end the month:

The Yamal nuclear-powered icebreaker is scheduled to leave for the drifting polar station on May 31, and it will take the ship about 10 days to reach NP-40.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ghoti on June 03, 2013, 09:09:23 PM
Buoy 2012G and the NP40 website both show the barometric pressure bombing out today. Passing 991 so far on it's way down. Have to wonder how much worse the ice fragmentation around the research camp can get.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Neven on June 03, 2013, 10:02:28 PM
Thanks, ghoti. I knew the cyclone moved to that zone, but forgot about NP-40. I used this compilation of the ECMWF 6-day forecast for my latest post on the ASIB:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fneven1.typepad.com%2F.a%2F6a0133f03a1e37970b01901cf13add970b-pi&hash=10e24b35c536b5e7653aacbef15f9ee2)

The cyclone could reach 980 hPa tomorrow, if I'm reading the map correctly, with 985 hPa after that. And then the cyclone should move away again.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on June 06, 2013, 07:32:56 PM
Chris and all,

For those interested in high pressure ridging impact on the Arctic and global climate, there is a 1 hour live streamed Climate Desk broadcase at 4:30 EDT today featuring Jennifer Frances and Stu Ostro from Weather.com

See the article at: http://www.motherjones.com/environment/2013/06/one-meteorologistss-come-jesus-moment-climate-change (http://www.motherjones.com/environment/2013/06/one-meteorologistss-come-jesus-moment-climate-change)

The live stream link is in the box under the lead photo on the right side.

A4R
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ritter on June 06, 2013, 10:13:27 PM
Chris and all,

For those interested in high pressure ridging impact on the Arctic and global climate, there is a 1 hour live streamed Climate Desk broadcase at 4:30 EDT today featuring Jennifer Frances and Stu Ostro from Weather.com

See the article at: http://www.motherjones.com/environment/2013/06/one-meteorologistss-come-jesus-moment-climate-change (http://www.motherjones.com/environment/2013/06/one-meteorologistss-come-jesus-moment-climate-change)

The live stream link is in the box under the lead photo on the right side.

A4R

Anybody know if this will be available after the fact?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: RaenorShine on June 06, 2013, 10:28:47 PM
Several others presentations by climate desk live are available to watch after the event on http://climatedesk.org/category/climate-desk-live/, (http://climatedesk.org/category/climate-desk-live/,) no specific mention on this one for definite though.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Jim Hunt on June 07, 2013, 11:17:26 AM
Some gaps in the cloud today, and some gaps in the ice (http://earthdata.nasa.gov/labs/worldview/?map=-924640,487949.390581,-121312,994829.390581&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines_3413,arctic_graticule_3413&time=2013-06-07&switch=arctic) too. Is this what the US Navy were predicting?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Whit on June 07, 2013, 11:50:16 AM
This is from a cloudless area between Jim's image and CAA (http://earthdata.nasa.gov/labs/worldview/?map=-1105023.63441,-51995.467249,-610943.63441,341220.532751&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines_3413&time=2013-06-07&switch=arctic). I have increased contrast, lowered exposure and increased the details to show the degree of fragmentation that's going on. To me it seems much more fragmented than in August last season.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Bob Wallace on June 07, 2013, 07:56:52 PM
What does "increased the details" mean?

Do you mean that you increased contrast and lowered brightness to make the details easier to see?   
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Whit on June 08, 2013, 01:05:18 PM
What does "increased the details" mean?

Do you mean that you increased contrast and lowered brightness to make the details easier to see?
It's just a simple sharpen filter. I suppose I coud do a better job if I used Photoshop or similar software.

I see that it got too dark too. That's what you get for editing on a laptop while commuting :)

Depending on the image and the screen I'm viewing it on, sometimes detail gets lost in the highlights. You can get some back through increasing contrast and pulling highlights, exposure or brightness. I guess we could get a lot more detail from the highlights if we had access to png or tiff-files. Information might get lost when they are converted to jpg, and when going from whatever native colorspace they use to sRGB.

I just started looking at this and I suspect I might be treading old ground ... I do remember a discussion at the blog about editing satellite images with GIMP.

Sorry for going OT Neven. Feel free to move.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Bob Wallace on June 08, 2013, 07:55:35 PM
Thanks.  I've sharpened thousands of images, I just had never heard it called "increasing details".  It's selective contrast boosting of edges, doesn't actually add new details.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Whit on June 08, 2013, 08:15:37 PM
Thanks.  I've sharpened thousands of images, I just had never heard it called "increasing details".  It's selective contrast boosting of edges, doesn't actually add new details.
Totally agree. Sharpening just makes details easier to see, but it doesn't add any information. However, detail in a high-resolution image can get lost when downsizing. Sharpening sometimes help, sa Im sure you're aware.

As a sidenote, Adobe calls the entire sharpening tool block "Detail". Apple Aperture calls it definition, and I have no idea what the similar function is called in GIMP. "Increasing detail" seemed more accessible at the time of writing :)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on June 08, 2013, 09:14:04 PM
For what it's worth I don't like the use of anything but negative, or contrast/brightness to bring out detail in MODIS or IR. There's too much risk that you're seeing the software, not reality.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Pmt111500 on June 09, 2013, 08:11:10 AM
only adjust "contrast/brightness to bring out detail in MODIS"

yes there's so much haze in the arctic it's difficult to know when the clouds above are thick enough to fool the sensors/eyes.  Add to that, segments of the image are taken at different times during the day, so some shadows are on one direction and other face the other way. There might be some protocol to take that into account, but as some people want to see the clouds, there would have to be another protocol to enhance the stratus or thin strips of thicker clouds. Further, as the stratus-clouds may be of different thicknesses, getting a maximum resolution of cracks must be done manually. Here's my attempt to remove most of the thin stratus from one image (took about 15 minutes), note how the shadows of the remaining thicker clouds get darker in the retouched image. And I may have taken a bit too much brightness away. Already there are some processing artifacts, like the one 'dark fracture' curving upper left from the middle right, due the inaccuracies in selecting areas of different adjustments.

method is simply picking the most cloud free area, adjusting the image so it shows the most detail, then just trying to get the rest  of the image looking continuous with it, using only brightness/contrast and using the 'lasso'-tool for selection

(modified) made another attempt of the Hudson Bay 6/6/2013 image, in this, there seems to be thick stratus on the southern coast so this method produces no additional detail there. also the blue ice gets darker and possibly vanishes in parts of the image. Note how the thicker clouds do not have a shadow, so these parts of the image must have been taken from the direction of the sun.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ghoti on June 13, 2013, 05:26:05 AM
O-Buoy 7 and 8 are finally returning webcam images. The are surrounded by slush.

http://obuoy.datatransport.org/monitor#buoy8/webcam (http://obuoy.datatransport.org/monitor#buoy8/webcam)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Pmt111500 on June 13, 2013, 07:42:14 AM
thanks Ghoti! It looks like the floe buoy8 is on, is about to crack. I think there's just rubble floating on the left side in the image. Does someone know how tall the yellow markers are?

modified 1,5 h later: no change in the crack yet, but as I've seen these (on thinner ice), when the crack is finalized, and dispersion begins it might take less than two hours to see the markers on the other side of the crack float away to the horizon.

modified 6,0 h later: been following the image occasionally among other chores, there might be slight tilt in the camera angle now. nothing significant looking happening on the ice-scape.

modified 7,5 h later: Ha, now the weather cleared up enough to see the general conditions around the buoy8, there are a couple of segments of pressure ridges on the background, otherwise it's pretty smooth and uniform ice-scape. There might be a small lead to the left but I'm no longer expecting anything to happen shortly here. It may be the buoy is on a floe on the lead, but the presence of pressure ridges is indicative of things not happening fast just now. Will check back after couple days, maybe the camera has tipped more by then.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Mike Fliss on June 13, 2013, 07:07:58 PM
Pmt111500:  "...how tall the yellow markers are?"  Check out Image 4 of 19 of 2012 Beaufort Gyre Deployment from O-BUOY web site:  http://www.o-buoy.org/?page_id=296 (http://www.o-buoy.org/?page_id=296)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: wanderer on June 13, 2013, 07:18:38 PM
So... the Fragmentation Event - remember March 10 or 26?

Is it to soon to talk about the impact?

Could it be, that the early fragmentation event actually helped the ice or will we see consequences later in melt season?

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Pmt111500 on June 14, 2013, 07:36:21 AM
Thanks Mike Fliss, it looks like the even-width section is about 30 cm? this would be about the freeboard of the ice floe. But, checking out the webcam, the camera has tilted so much the lead is no longer visible. Might it be the part of the floe it's on has wedged itself in an angle to the edge of the lead, or is the floe just disintegrating totally, i can't say. This would be the second time I've tried to follow the arctic webcams keeping them on the desktop all the time, and both times it's happened that most dramatic movements have happened overnight (I'm in Europe).
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: lanevn on June 14, 2013, 08:57:13 AM
So... the Fragmentation Event - remember March 10 or 26?

Is it to soon to talk about the impact?

Could it be, that the early fragmentation event actually helped the ice or will we see consequences later in melt season?

I think we can't say anything about impact of fragmentation event, because difference in wheather conditions this and last years impact much more.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on June 17, 2013, 04:47:11 AM
I ran across a blog that looked at the heat release that occurred during the fragmentation event this spring. The point of the comments and physics (not my field), is that huge amounts of energy were released from the Arctic waters in this process through the winter.

I am left thinking about whether this release of energy from warmer water before refreeze in each event may lower the amount of latent heat or energy that would cause bottom melt through the summer.

The title of the comments is: Arctic Ocean sensible heat loss

The link is: http://mallemaroking.org/arctic-ocean-sensible-heat-loss/ (http://mallemaroking.org/arctic-ocean-sensible-heat-loss/)

A4R
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: anonymous on June 17, 2013, 08:40:15 AM
I am left thinking about whether this release of energy from warmer water before refreeze in each event may lower the amount of latent heat or energy that would cause bottom melt through the summer.

I like the article, however it would help to put this in context, if the total Arctic heat budget had been given. Locally the numbers are impressive - Giga Watts!, but isn't the total amount in the Arctic some magnitudes greater?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: jdallen on June 17, 2013, 09:09:22 AM
Yes, as in thousands of terawatts, measured across the entire basin.  That is just considering the regions being hit by sunlight, at somewhere on the order of 350-400 watts/sq meter, 16+ hours a day.

Obviously albedo reduces that, but that approximates the scales of energy we are talking about.  Factor in transport via currents into and out of the arctic, and you expand the budget even further.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger on June 17, 2013, 10:55:16 AM
Hi folks,

Yes, heat was released to the atmosphere over Feb/Mar 2013. But the effect on the energy budget is uncertain. More heat released -> warmer atmosphere -> slower sea ice accretion. There was some effect on N80 temperatures (http://ocean.dmi.dk/arctic/meant80n.uk.php), but perhaps less than Spring 2012 which also had less fracturing. Usually, Winter is long enough that sea ice reaches it's 2m equilibrium thickness before the Summer melt begins, regardless of weather wiggles.

The two unknowns for 2013 are what is the effect on sea ice transport (http://en.wikipedia.org/wiki/Heat_transfer#Advection), and does this influence overcome any local sea ice thickening that occurred due to pressure ridging (http://en.wikipedia.org/wiki/Pressure_ridge_%28ice%29).

So, this resolves to a thermal hydraulics (http://en.wikipedia.org/wiki/Thermal_hydraulics) issue:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fupload.wikimedia.org%2Fmath%2Fe%2F2%2F3%2Fe23bc2c3e3b12c223a73bc49d6bb823d.png&hash=f484afd9d9ab788d79688669ed225fff)

where Q is heat flux (W/m²), ρ is density (kg/m³), c_p is heat capacity at constant pressure (J/(kg*K)), ΔT is the change in temperature (K), v is velocity (m/s).

Anybody care to have a go?  ;)

Basically, if the fracturing event allows more of the Arctic ice cold store to be lost via advection later in the Summer than it added in new pressure ridges over the Winter, then the event is a net loss of Arctic sea ice.

Traditionally, over half of the total volume of Arctic sea ice is contained in these pressure ridges, so this is a major issue. If this thickest ice is advected through Fram or Nares strait, the issue is pretty much settled.

So let's watch and see what happens.  8)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: anonymous on June 17, 2013, 12:38:14 PM
So, this resolves to a thermal hydraulics (http://en.wikipedia.org/wiki/Thermal_hydraulics) issue:
AD, do your technical skills now include invisible irony tags?
Title: NCAR Sea Ice Age charts gone??
Post by: Artful Dodger on June 18, 2013, 02:08:31 PM
So, this resolves to a thermal hydraulics (http://en.wikipedia.org/wiki/Thermal_hydraulics) issue:
AD, do your technical skills now include invisible irony tags?

lol ArcticIO, my Irony Man suite is at the cleaners ;)

Irony Man (http://www.youtube.com/watch?v=vE3lVR0oU2Y#ws)

Say, has anybody else noticed that the ftp folder (ftp://ccar.colorado.edu/pub/tschudi/iceage/gifs/) holding Chuck Fowler's weekly Sea Ice Age charts is empty? Anybody know wassup?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 25, 2013, 01:10:56 AM
The long sought after negative feedback

Fragmentation event in winter > open water > loss of heat from Arctic Ocean > lower atmospheric pressure > more clouds > less sunlight > more precipitation > more sea ice
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: jdallen on June 25, 2013, 01:34:26 AM
The long sought after negative feedback

Fragmentation event in winter > open water > loss of heat from Arctic Ocean > lower atmospheric pressure > more clouds > less sunlight > more precipitation > more sea ice

You're throwing together a series of states and events which don't necessarily follow. Further, some of which are completely independent of one another.  E.G., fragmentation event in winter leads to less insolation?  More precipitation leads to more sea ice?

I think you need to give us some more substance.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Shared Humanity on June 25, 2013, 01:43:06 AM

I think you need to give us some more substance.

He's testing out new threads. He's been providing substance for some time over in the "Consequences" topics.   ;)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 25, 2013, 01:47:10 AM
The long sought after negative feedback

Fragmentation event in winter > open water > loss of heat from Arctic Ocean > lower atmospheric pressure > more clouds > less sunlight > more precipitation > more sea ice

You're throwing together a series of states and events which don't necessarily follow. Further, some of which are completely independent of one another.  E.G., fragmentation event in winter leads to less insolation?  More precipitation leads to more sea ice?

I think you need to give us some more substance.

It's physics.

The arrows weren't meant to mean one thing has to follow the other, but fragmenting the sea ice when it is insulating the ocean allows all those things to happen. There is also no rule the affects of the atmosphere have to remain above the arctic sea ice. Venting heat is lowering pressure.

More sea ice is created just by having open spaces for it to form. More sea ice is created by chilling the ocean below.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 25, 2013, 01:48:01 AM

I think you need to give us some more substance.

He's testing out new threads. He's been providing substance for some time over in the "Consequences" topics.   ;)

I guess you think science is only what you choose to believe.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: jdallen on June 25, 2013, 02:16:27 AM

I think you need to give us some more substance.

He's testing out new threads. He's been providing substance for some time over in the "Consequences" topics.   ;)

I guess you think science is only what you choose to believe.

Please, spare the insults; that's not generally a good response when someone questions one's assertions. I have a modest understanding of The physical sciences. My request and questions still stand.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 25, 2013, 02:25:53 AM
CIRES - Loss Of Polar Sea Ice Exercising Biggest Influence Over Weather, Jet Stream In Fall, Winter

Shrinking Arctic sea ice is shifting polar weather patterns, especially in fall and winter, a new climate modeling study finds.
 
For the study, researchers looked at weather patterns in 2007, when sea ice covering the Arctic Ocean hit one of its lowest summer extents since satellite tracking began in the late 1970s.
 
In fall and winter, when sea ice would normally insulate the ocean from frigid Arctic air temperatures, the small ice pack meant lots of heat could escape from the ocean into the atmosphere, the study found. The heating changed atmospheric circulation patterns in the Arctic, said lead study author Elizabeth Cassano, a climate scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES) in Boulder, Colo. The results were published May 21 in the International Journal of Climatology.
 
"What we saw, particularly in the fall and winter, was a decrease in pressure over the areas of open water," Cassano told LiveScience. Areas of high and low pressure drive weather, with low pressure producing stormier weather and high pressure leading to clear, calm days, Cassano said. The group's computer model generally agreed with weather records from the latter half of 2007, according to the study.

Source: http://www.democraticunderground.com/112745276 (http://www.democraticunderground.com/112745276)

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: BornFromTheVoid on June 25, 2013, 02:56:35 AM
It's physics.

The arrows weren't meant to mean one thing has to follow the other, but fragmenting the sea ice when it is insulating the ocean allows all those things to happen. There is also no rule the affects of the atmosphere have to remain above the arctic sea ice. Venting heat is lowering pressure.

More sea ice is created just by having open spaces for it to form. More sea ice is created by chilling the ocean below.

The fragmentation event occurred between February and March. March then had the most -ve AO on record.

Perhaps the difference between the vented heat and the local air is only large enough in Autumn and Winter to promote the kind of low pressure scenario you predict?
Makes sense really. By Autumn much of the Arctic ocean has heated up above 0C, some areas well above 0C, and as that heat is released (as the air is trying to cool down to -20 or -30C) the increased buoyancy from that warmth encourages lower pressure than normal to occur.

By February and March, much of the oceans heat has already been released and any cracks are quickly frozen over, not allowing much time for any significant heating of the overlying air, unlike in Autumn, when it can take weeks to cool the ocean down enough to freeze.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 25, 2013, 04:27:13 AM
It's physics.

The arrows weren't meant to mean one thing has to follow the other, but fragmenting the sea ice when it is insulating the ocean allows all those things to happen. There is also no rule the affects of the atmosphere have to remain above the arctic sea ice. Venting heat is lowering pressure.

More sea ice is created just by having open spaces for it to form. More sea ice is created by chilling the ocean below.

The fragmentation event occurred between February and March. March then had the most -ve AO on record.

Perhaps the difference between the vented heat and the local air is only large enough in Autumn and Winter to promote the kind of low pressure scenario you predict?
Makes sense really. By Autumn much of the Arctic ocean has heated up above 0C, some areas well above 0C, and as that heat is released (as the air is trying to cool down to -20 or -30C) the increased buoyancy from that warmth encourages lower pressure than normal to occur.

By February and March, much of the oceans heat has already been released and any cracks are quickly frozen over, not allowing much time for any significant heating of the overlying air, unlike in Autumn, when it can take weeks to cool the ocean down enough to freeze.

I didn't take the measurements of air pressure and didn't predict it. I'm going by what was reported as a consequence of losing the heat and it makes sense.

The fragmentation event wouldn't create a low pressure system, but the open water and heat release would lower pressure until it recovered. It is strange that an event lowering pressure managed to produce record high pressure, if that was the reason for the record neg AO.

Perhaps there is something in the timing where so much heat is removed that the new equilibrium is putting less heat into the atmosphere than it originally did. I'm thinking the chilled ocean upper layer later added to the original insulation. It would be nice to know how quickly sea ice can freeze back under those conditions.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 25, 2013, 05:49:30 AM
Does detailed IR satellite data exist for the arctic that can accurately measure the heat escaping from the sea ice and notice a change?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: sofouuk on June 25, 2013, 08:07:38 AM
ggelsrinc, unless I'm missing something, your chain doesn't make any sense at all. the fragmentation event happened in the middle of winter; there was no insolation to reduce, and any resulting lower atmospheric pressure would have been transitory. there's no way that effect, assuming it exists to any significant degree, would have persisted through into the start of the melt season. I agree that the fragmentation event would have thickened the ice in places, but that hardly merits a grand title like 'the long sought after'. it happened once, and it was a freak weather event. unless you think something similar is now going to happen every winter, it would make more sense to view it as just delaying the decline by a single year. that's all
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: BornFromTheVoid on June 25, 2013, 11:23:28 AM
It's physics.

The arrows weren't meant to mean one thing has to follow the other, but fragmenting the sea ice when it is insulating the ocean allows all those things to happen. There is also no rule the affects of the atmosphere have to remain above the arctic sea ice. Venting heat is lowering pressure.

More sea ice is created just by having open spaces for it to form. More sea ice is created by chilling the ocean below.

The fragmentation event occurred between February and March. March then had the most -ve AO on record.

Perhaps the difference between the vented heat and the local air is only large enough in Autumn and Winter to promote the kind of low pressure scenario you predict?
Makes sense really. By Autumn much of the Arctic ocean has heated up above 0C, some areas well above 0C, and as that heat is released (as the air is trying to cool down to -20 or -30C) the increased buoyancy from that warmth encourages lower pressure than normal to occur.

By February and March, much of the oceans heat has already been released and any cracks are quickly frozen over, not allowing much time for any significant heating of the overlying air, unlike in Autumn, when it can take weeks to cool the ocean down enough to freeze.

I didn't take the measurements of air pressure and didn't predict it. I'm going by what was reported as a consequence of losing the heat and it makes sense.

The fragmentation event wouldn't create a low pressure system, but the open water and heat release would lower pressure until it recovered. It is strange that an event lowering pressure managed to produce record high pressure, if that was the reason for the record neg AO.

Perhaps there is something in the timing where so much heat is removed that the new equilibrium is putting less heat into the atmosphere than it originally did. I'm thinking the chilled ocean upper layer later added to the original insulation. It would be nice to know how quickly sea ice can freeze back under those conditions.

The reported consequence was for Autumn and Winter, not Spring or early summer. That's where I believe, as I described in my previous post, that the disconnect lies.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: wanderer on June 25, 2013, 11:27:05 AM
It seems like we might see another fragmentation event- likely because of the old one!

http://earthdata.nasa.gov/labs/worldview/?map=-2559040,-914432,-786496,263168&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines_3413&time=2013-06-24&switch=arctic (http://earthdata.nasa.gov/labs/worldview/?map=-2559040,-914432,-786496,263168&products=baselayers,MODIS_Terra_CorrectedReflectance_TrueColor~overlays,arctic_coastlines_3413&time=2013-06-24&switch=arctic)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 25, 2013, 01:29:01 PM
ggelsrinc, unless I'm missing something, your chain doesn't make any sense at all. the fragmentation event happened in the middle of winter; there was no insolation to reduce, and any resulting lower atmospheric pressure would have been transitory. there's no way that effect, assuming it exists to any significant degree, would have persisted through into the start of the melt season. I agree that the fragmentation event would have thickened the ice in places, but that hardly merits a grand title like 'the long sought after'. it happened once, and it was a freak weather event. unless you think something similar is now going to happen every winter, it would make more sense to view it as just delaying the decline by a single year. that's all

It isn't a chain. Everything after fragmentation event are the logical consequences of a fragmentation event in winter. The best way to look at it is a fragmentation event happens or doesn't and what are the logical consequences of both scenarios.

On the Arctic Sea Ice Blog, they once discussed if there was any kind of negative feedback that could prevent the sea ice from melting out or slow global warming. If sea ice starts fragmenting in winter, it would be a negative feedback to sea ice loss. The change to a positive AO could be a negative feedback by reducing insolation during the melting times.

I don't view the sea ice as living in it's own private world and over the month the original air masses left the arctic. The lower pressure inflluenced the air masses that were present at the time and the amount of influence changed with time. Are you saying lowering air pressure in the arctic can't cause additional clouds on Earth? Fragmentation should produce a pulse of heat similar to rainforest storms.

Another thing commonly stated that is an oversight is talking about the melt season. The fragmentation event wasn't near where the melt season began. There was no melt season in that area; the melt season starts at lower latitudes. Have you seen Beaufort wanting to melt out now? The melt season in the area of the fragmentation event occurs when conditions no longer can make sea ice faster than it melts.

I wondered if the fragmentation event could help the sea ice and from what I read in brine rejection studies, brine rejection happens quicker than I thought. Previously, my opinion on how fast sea ice could form and reject brine was based on hearsay.

What we really need to examine the fragmentation event are satellite IR images that show the heat leaving the sea ice. I don't know if a satellite is set up that way.   
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: jdallen on June 25, 2013, 05:31:24 PM
What we really need to examine the fragmentation event are satellite IR images that show the heat leaving the sea ice. I don't know if a satellite is set up that way.

Could that be derived indirectly, via comparison of surface (2 meter) vs 850PA temps?  Would be mostly anecdotal, as there are so many variables, but we might be able to get a sense of it.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 25, 2013, 05:38:22 PM
What we really need to examine the fragmentation event are satellite IR images that show the heat leaving the sea ice. I don't know if a satellite is set up that way.

Could that be derived indirectly, via comparison of surface (2 meter) vs 850PA temps?  Would be mostly anecdotal, as there are so many variables, but we might be able to get a sense of it.

I find knowing how much heat was released by the fragmentation event and knowing how much heat the sea ice was giving off before and after the fragmentation event would be very important information. Finding that fragmentation event ultimately chilled the arctic could explain why the arctic had a record negative AO following the event.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: BornFromTheVoid on June 25, 2013, 05:59:30 PM
What we really need to examine the fragmentation event are satellite IR images that show the heat leaving the sea ice. I don't know if a satellite is set up that way.

Could that be derived indirectly, via comparison of surface (2 meter) vs 850PA temps?  Would be mostly anecdotal, as there are so many variables, but we might be able to get a sense of it.

I find knowing how much heat was released by the fragmentation event and knowing how much heat the sea ice was giving off before and after the fragmentation event would be very important information. Finding that fragmentation event ultimately chilled the arctic could explain why the arctic had a record negative AO following the event.

I really don't think it could go anyway explain the record -ve AO. Any possible cooling from the fragmentation event would have been to the water, not the air, as freezing water releases heat. Besides, surface air temperatures in March were above average.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Peter Ellis on June 25, 2013, 08:04:59 PM
I really don't think it could go anyway explain the record -ve AO. Any possible cooling from the fragmentation event would have been to the water, not the air, as freezing water releases heat. Besides, surface air temperatures in March were above average.

This seems exceptionally confused.  During the cracking event, comparatively warm water (above freezing) will have been exposed to the much colder air above.  This means that the ocean will lose heat as the new ice forms in the leads, and the atmosphere will correspondingly be warmed slightly.  This is entirely consistent therefore with above average air temperatures, increased heat loss from the ocean, and an overall increase in ice formation.  It's not complicated!
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: BornFromTheVoid on June 25, 2013, 08:39:29 PM
I really don't think it could go anyway explain the record -ve AO. Any possible cooling from the fragmentation event would have been to the water, not the air, as freezing water releases heat. Besides, surface air temperatures in March were above average.

This seems exceptionally confused.  During the cracking event, comparatively warm water (above freezing) will have been exposed to the much colder air above.  This means that the ocean will lose heat as the new ice forms in the leads, and the atmosphere will correspondingly be warmed slightly.  This is entirely consistent therefore with above average air temperatures, increased heat loss from the ocean, and an overall increase in ice formation.  It's not complicated!

You're not quite getting me, in fact you're repeating what I'm saying!

ggelsrinc is suggesting that the fragmentation event may have cooled the Arctic air, resulting in the higher pressure that caused the record -ve AO

"Finding that fragmentation event ultimately chilled the arctic could explain why the arctic had a record negative AO following the event."

So I said that the cooling would have happened to the water, not the air, as "freezing water releases heat". I then suggested that the record -ve AO could not have been caused by cooling of the Arctic anyway, as surface air temperatures were above average during March.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Peter Ellis on June 25, 2013, 08:47:03 PM
Fair enough.  As you were :-)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: TerryM on June 25, 2013, 08:47:55 PM
As I recall the open waters in the fractures caused lots of cloud/mist formation that would hamper radiation into space. I'd expect the ocean heat that was released would have had some effect on the nearby ice rather than simply being radiated away. Any precipitation would be as blanketing snow that would act to protect the ice from the very cold air.  The possibility of wave action & grinding may fragment some of the ice. These factors combined could equate to a positive feedback.
Once the leads have iced over there is still a lot of heat being released through the thin ice, but no additional water vapor. At this stage the fractures represent negative feedback.


My guess is that winter fracturing is a net negative feedback, though probably not a large one.


Terry
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ggelsrinc on June 26, 2013, 01:51:13 AM
As I recall the open waters in the fractures caused lots of cloud/mist formation that would hamper radiation into space. I'd expect the ocean heat that was released would have had some effect on the nearby ice rather than simply being radiated away. Any precipitation would be as blanketing snow that would act to protect the ice from the very cold air.  The possibility of wave action & grinding may fragment some of the ice. These factors combined could equate to a positive feedback.
Once the leads have iced over there is still a lot of heat being released through the thin ice, but no additional water vapor. At this stage the fractures represent negative feedback.


My guess is that winter fracturing is a net negative feedback, though probably not a large one.


Terry

I think the heat would quickly be removed from the arctic.

The way I see it, the sea ice fractures and releases heat to whatever air mass is above. Not only does the heat rise in that air mass, but that air mass isn't going to be around the arctic for long. I also see colder air moving in to replace any warmer rising air and that is the perfect conditions for sea ice formation in open water. Not only has the ocean water lost heat, but the volume of sea ice increases and so does it's insulating ability. That would explain the record neg AO resulting from the completed process.

It looks like an ice maker to me and an event that would make the near term future colder.

If fragmentation events like that became common, it would become a negative feedback to losing sea ice and a negative feedback to warming.   
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: JMP on June 26, 2013, 08:02:17 AM
As I recall the open waters in the fractures caused lots of cloud/mist formation that would hamper radiation into space. I'd expect the ocean heat that was released would have had some effect on the nearby ice rather than simply being radiated away. Any precipitation would be as blanketing snow that would act to protect the ice from the very cold air.  The possibility of wave action & grinding may fragment some of the ice. These factors combined could equate to a positive feedback.
Once the leads have iced over there is still a lot of heat being released through the thin ice, but no additional water vapor. At this stage the fractures represent negative feedback.


My guess is that winter fracturing is a net negative feedback, though probably not a large one.


Terry
Saw this (http://www.arctic.noaa.gov/essay_wadhams.html (http://www.arctic.noaa.gov/essay_wadhams.html)) earlier and if i'm understanding it correctly Wadhams is saying that the heat loss is quite significant. And, as the leads close the newly formed ice is pushed up and down which greatly increases the thickness of the ice also.   
In winter leads rapidly refreeze because of the enormous temperature difference between the atmosphere (typically -30°C) and the ocean (-1.8°C). The heat loss from a newly-opened lead can be so violent (more than 1000 W m-2) that the lead steams with frost smoke from the evaporation and condensation of the surface water. A young ice cover rapidly forms, within hours, as nilas if the surface is calm, and this cuts out the evaporation. When a subsequent wind stress field becomes convergent, the young ice in the refrozen leads forms the weakest part of the ice cover and is the first part to be crushed, building up heaps of broken ice blocks above and below the water line. Such a linear deformation feature is called a pressure ridge, the above-water part being the sail and the below-water part (more extensive) being called the keel. Keels in the Arctic can reach down to 50 m, although most are about 10-25 m deep. Ridged ice in the Arctic makes a major contribution to the overall mass of sea ice; probably about 40% on average and more than 60% in coastal regions.

The effect of this would seem to be self limiting -- once the ice builds up sufficiently it wont fracture so easily, less heat will escape and the relatively warmer water will act on the ice as before.  We shall see how this plays out of course but I seriously doubt that the ice could possibly be able to overcome the downward death spiral -- even if we do see some re-building for a couple of years (at most). 
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: jdallen on June 26, 2013, 08:18:18 AM
If I recall, the leads don't stay open long enough to release a lot of energy, inspite of the huge gradient.

Second, while the initial formation is quick - the initial freeze of the surface - new ice on the lead caps and insulates the water from *as* rapid energy loss.  Instead of being dumped into the atmosphere, it goes into ice formation, to the tune of about 10CM/degree C below the freezing point of salt water.

This however, takes a fairly significant amount of time, increasing as the ice thickens, and thus adds additional barriers to the transfer of energy.

The ice that is formed, comparatively is quite weak - first year ice.  To become sturdy, it needs time to age, expel salt and transform into MYI.  Until then, it is significantly more vulnerable to seasonal changes.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Nightvid Cole on June 26, 2013, 05:02:33 PM
As I recall the open waters in the fractures caused lots of cloud/mist formation that would hamper radiation into space. I'd expect the ocean heat that was released would have had some effect on the nearby ice rather than simply being radiated away. Any precipitation would be as blanketing snow that would act to protect the ice from the very cold air.  The possibility of wave action & grinding may fragment some of the ice. These factors combined could equate to a positive feedback.
Once the leads have iced over there is still a lot of heat being released through the thin ice, but no additional water vapor. At this stage the fractures represent negative feedback.


My guess is that winter fracturing is a net negative feedback, though probably not a large one.


Terry

I'm not so sure it is a net negative, since the new ice is more transmissive to sunlight and allows more heating of the upper ocean in the spring.

And once that ice breaks up (which will happen much sooner than the surrounding, thicker ice), there could be enough room for swells to form inside the area, and thus break up the surrounding ice, although to be fair the wind speeds would have to be very high for this to make much difference...
Title: Re: NCAR Sea Ice Age charts gone??
Post by: Jim Hunt on June 29, 2013, 07:56:20 PM
Say, has anybody else noticed that the ftp folder (http://ftp://ccar.colorado.edu/pub/tschudi/iceage/gifs/) holding Chuck Fowler's weekly Sea Ice Age charts is empty? Anybody know wassup?

I don't know what was up Lodger, but the folders have now filled up again.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on June 29, 2013, 08:03:24 PM
Their FTP server was empty some weeks ago. I hadn't bothered checking after that because Mark Tschudi told me their stuff was being moved to NSIDC, and I assumed that was in progress. Obviously not.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger on June 30, 2013, 08:59:20 AM
Thanks, Jim and Chris.

I see the ftp folder (ftp://ccar.colorado.edu/pub/tschudi/iceage/gifs/) is populated again now.  8)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: ChrisReynolds on June 30, 2013, 10:07:38 AM
Lodger,

It may be best to save them as they come up, I've got a folder with the most recent years at 4 week intervals. I'm not a fan of the user friendliness of NSIDC products, if they are going to move to NSIDC I'm not confident it will be easy to get those images - at least not as easy as from that file server.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger on June 30, 2013, 10:14:34 AM
It may be best to save them as they come up

Hi Chris,

Yes, I agree. I've got 2012_01 thru latest on local storage now.
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Apocalypse4Real on July 04, 2013, 11:03:42 PM
The Siberian Times has interesting comments from the North Pole 40 science team after their return this week. Here are the highlights:

"The 16 scientists were in danger of sinking on an ice floe that had shrunk ten times.
Nikolai Fomichev, chief of the drifting ice North Pole 40-40 station, said: 'The cracks went right through the ice field, dividing it into four separate floes - and never froze back.'

http://siberiantimes.com/science/casestudy/news/after-a-250-day-1640-km-drift-in-the-arctic-ocean-crew-from-north-pole-40-station-is-back-on-shore/ (http://siberiantimes.com/science/casestudy/news/after-a-250-day-1640-km-drift-in-the-arctic-ocean-crew-from-north-pole-40-station-is-back-on-shore/)

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: dbostrom on July 05, 2013, 06:59:59 AM
If the plot shown on the map in the article quoted by Apocalypse4Real is the course of the Yamal, perhaps that's an indication of the health of Arctic sea ice in general?
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Steven on July 11, 2013, 01:43:33 PM
It might only be me but looks like one of the the large fractures in the Beaufort Sea earlier this year has survived all the ice movement. By it's colour the ice there looks very thin. Interesting to see what happens if it melts out before the rest of the pack and the results of that.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fs10.postimg.org%2Frgixt2yw5%2FBaufortcrack.jpg&hash=5a94decc30c7fe28b7135c6e69acb825) (http://postimg.org/image/rgixt2yw5/)
Spotted that the other day - it's definitely the biggest of the fractures from March, you can track all the way from then until now on ASCAT.
Others have probably noticed this:  It appears that the ice in the old fracture became thin enough to show up as a polynya in some of the concentration maps, a few hundreds of kilometers north-northeast of Barrow:

https://sites.google.com/site/apamsr2/home/pngcby32/ (https://sites.google.com/site/apamsr2/home/pngcby32/)

http://www.iup.uni-bremen.de:8084/amsr2data/asi_daygrid_swath/n6250/2013/jul/asi-AMSR2-n6250-20130710-v5_nic.pdf (http://www.iup.uni-bremen.de:8084/amsr2data/asi_daygrid_swath/n6250/2013/jul/asi-AMSR2-n6250-20130710-v5_nic.pdf)

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on August 10, 2013, 07:17:42 PM
Nothing profound to say here, Just noticed a feature that would have been useful. TOPAZ has an age of first year ice feature. The ice in the Beaufort negative aged in March, so Topaz followed the cracking event accurately.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FbH3ltip.png&hash=d51eda4797502c75e2fc5d0bf5b80040)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FCyTf3MZ.png&hash=47676bef354528f69746c133089bf7d8)

Vergent
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger on August 10, 2013, 11:31:02 PM
Nothing profound to say here, Just noticed a feature that would have been useful. TOPAZ has an age of first year ice feature. The ice in the Beaufort negative aged in March, so Topaz followed the cracking event accurately.

Verge! Good digg!  8)

Can you share a little on how to navigate to that feature? You know, for the kids?  ;)
Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Vergent on August 11, 2013, 01:39:41 AM
Lodger

Sure, Go to:

http://www.myocean.eu/web/24-catalogue.php (http://www.myocean.eu/web/24-catalogue.php)

Search; arctic ocean, sea ice, forecast products

TOPAZ4 will be the search result. Select view. You get a dumbed down Godiva type interface(no animate, darn). It's on the menu.

Vergent

Title: Re: Fragmentation Event. Will it have impact over the summer melt season?
Post by: Artful Dodger on August 11, 2013, 06:17:56 AM
Lodger

Sure, Go to:

Gracias, Verge!  :D