On the move

When A-Team is not improving masterpiece paintings, he makes great animations. Here's yet another one, showing the speed with which the cracked ice pack in the Beaufort Sea has been moving in past weeks:

The largest crack functions as a reference point. In the Arctic Sea Ice Forum I jokingly said Banks Island fits in there - okay, I acted as if it was a joke when it turned out I had it wrong -, but it's still pretty big. I'm very curious what will happen once the thin ice in that crack gets properly introduced to the Sun.

According to A-Team's calculations (which he probably does while painting):

The Beaufort ice pack is very much on the move. The fast-moving western tip of a recognizable central feature, traced for 41 days (23 Feb 13 to 02 Apr 13), has moved 479 km or 11.7 km per day at 0.49 km per hour. The angular velocity about the feature's Euler pole at 82.5ºN 140ºW is quite rapid, about 1.2º per day.

As evidenced by the 60-day drift track of the IABP buoys in the Beaufort area:

And it's not over yet. We have yet another blue high pressure area:

That high is going to weaken, but it'll pull at the ice a bit more for a couple of days before moving away. The cracking event is slowly making way for the consequences of the cracking event.

Comments

[Villabolo]

@Neven,

"I'm very curious what will happen once the thin ice in that crack gets properly introduced to the Sun."

When can we expect those leads to melt?

[Neven]

Villabolo, judging by the sea ice concentration maps of 2008, 2011 and 2012 on the ASIG I'd say from mid-May onwards.

[Robert Fanney]

@ Neven

ECMWF shows a strong low emerging from Siberia into the Arctic by April 13. A long way out. But, perhaps, worth keeping an eye on.

Great post. The ice mobility looks freakishly fast at the moment.

One more little feature to mention and I'm back to lurking/research: Nuuk Greenland high for today was 48 degrees F.

Best...

[Tor Bejnar]

Projected ice movement, per the ARC ice speed & drift maps (on Daily Graphs page) have winds nudging much of the thickest ice westward - toward the Beaufort Sea - over the next 5 days. The recent cracking just north of Greenland and the Canadian Archipelago will allow the ice to actually move. It won't move 1/2 km/hr, but it'll move.

There is hardly any fast ice left. (Well, it is now "fast" in a different way.) When I first started watching (several years ago) some of it seemed so robust! No more.

This movement trend will lead to less thick ice going out the Fram. It will just melt in the Arctic Ocean over the next few summers. (Plenty of other ice will go south, probably keeping up with the historical volume of export through Fram Strait.)

[Paul Beckwith]

Has anyone tried to estimate the total surface area of the ice this year including that of all the cracks versus that of the ice last year? Clearly, the melt rate is proportional to the total surface area which is much larger this year. Do the cracks double the total area, or triple it, or what?

[Protege Cuajimalpa]

Congrats to A-Team for this fantastic animation!

[Espen Olsen]

A-Team,

I am afraid you are turning ASIB from under-ice to mainstream? ;-)

[Steve Bloom]

Just to be clear, Paul, are you referring to a decrease in albedo due to an increase in surface roughness?

If so, I wonder if one or more of the sat sensors would render that pretty directly, although clouds would have to be masked out.

[wanderer]

Huge extent drop (200k):
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

2011 extent comes into reach.

[Neven]

TypePad has answered my question and it seems the problem with normal comments getting tagged as spam has to do with them switching to a new spam system (called Impermium). They advise to keep publishing the comments manually, and that should help the spam system.

So I'm trying to get it into my routine to check the spam folder at least once an hour and publish all comments. Sorry for the inconvenience. :-(

[wayne]

"Villabolo, judging by the sea ice concentration maps of 2008, 2011 and 2012 on the ASIG I'd say from mid-May onwards."

Not really Neven, Its melting now, that is why the ice movement is so fast, as expected, it will not stop, especially with a high pressure system in tandem with the Arctic Ocean Gyre. The low sun is not as weak as it appears to be, will have more on this, a world wide first this weekend or the next.

NSIDC latest prognostication was right on, especially by featuring multi-year ice extent. And not to forget, it is wise to use the end of ice extent build up as the coming of Spring. Now if they can only get that Anticyclones create leads they will be up to speed with this site!

[Neven]

Maybe I'm too conservative, and I based myself on Uni Bremen sea ice concentration maps which tend to show open water later than for instance LANCE-MODIS, but I don't expect the ice in those leads to massively melt out before the end of this month.

[Chris Reynolds]

Wayne,

"Not really Neven, Its melting now, that is why the ice movement is so fast, as expected, it will not stop, especially with a high pressure system in tandem with the Arctic Ocean Gyre."

I have to disagree, temperatures on the IR images are still way below zero.
http://www.weatheroffice.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

Melt may start in May, it really gets going in early June. Until then the behaviour of area/extent metrics aren't likely to tell us much about the conditions that count - within the Arctic Ocean Basin itself.

[Paul Beckwith]

I think that it is fair to say that the vast majority of the ice area/volume loss at the moment is export out Fram. If someone can calculate that export from the flow velocities and relate it to the 200k drop for example, that would be interesting.

The cracking does create albedo "hot spots"; I was jumping up and down on the glacier on my driveway and looking at the crack melting at the end of the day yesterday. But also when the melting gears up it the cracks provide a much larger interface with the air and ocean to accelerate melting as compared to solid ice. Similar to erosion rates for weathering rock. Also, the crack regions are highly stressed, so the higher internal energy leads to faster melt rates.

In the sea ice thickness movie over the last year there are many cracks visible during the freeze-up, especially noticeable in November. I suspect that some of the major cracks today are the same ones, i.e. crack persistence throughout the year. Not sure; boning up on my ice rheology... http://www.sciencedirect.com/science/article/pii/S0012821X06008430#

[OldLeatherneck]

If today's IJIS Extent loss (>200K)stands, it would be the greatest one day loss in the month of April. I did a quick survey of the April daily losses since 2003. Prior to 2012, there were only three times that the daily loss exceeded 100K. However, in 2012 it occurred 7 times. And we all know how much fun 2012 was. The below table was my first cut at looking at daily losses for the month of April. Buckle your seatbelts...it's going to be rough sailing this summer!!

[Paul Beckwith]

@OldLeatherneck

It would also be useful to post the area on those days (or split(extent/area) or spread (extent - area)); that would indicate if the ice was being exported out the Fram Strait or just being packed closer together within the Arctic basin.

[OldLeatherneck]

Paul,

I would be happy to post the area data for the same dates, however, I'm not sure where to find the raw data that I can export directly into excel. I'm still a novice when it comes to exploring all of the resources and data sources available. Any suggestions would be most welcome.

Thanks

[Espen Olsen]

OldLeatherneck;

Be careful with these pre-season figures, to say it at least!

[OldLeatherneck]

Quoting Espen:

OldLeatherneck;

Be careful with these pre-season figures, to say it at least!

Good reminder, however, I'm aware that we are still in "Spring Training" and the daily win/loss records won't count until the "Regular Season" starts next month.

[Espen Olsen]

OldLeatherneck;

It is always good with some training, but I guess you are used to be in alert mode?
I can promise you there will be a lot this season to watch and report so stay fit!

[Neven]

That IJIS number could very well be revised tomorrow, so keep them horses in yer stable.

[Chris Reynolds]

Old Leatherneck,

Regards CT Area in Excel, this might help:
http://forum.arctic-sea-ice.net/index.php/topic,155.0.html

[Chris Reynolds]

PS Old Leatherneck.

CT Area Data:
http://arctic.atmos.uiuc.edu/cryosphere/timeseries.anom.1979-2008
Column's are:
Date.
Area Anomaly.
Area.
Average used to calculate anomaly.

[OldLeatherneck]

Chris,

Thanks for the links!!!

[Artful Dodger]

Tor Bejnar wrote | April 04, 2013 at 01:15

"This movement trend will lead to less thick ice going out the Fram."

Sorry but No, Tor. Just the opposite has occurred this Winter. Look at the bottom image from the Apr 2, 2013 NSIDC update: (click this image to see full-rez 800x1622)

It shows clearly that about 25% of the MYI remaining on Dec 2nd was advected from the Central Arctic through Fram strait by Mar 28. This occurred in less than 4 months, and the process is ongoing.

Compare this with climate models that assume an annual figure of 10% advection of MYI, and you will understand that we are witnessing the Arctic sea ice death spiral.

The drain is Fram strait, and it is unplugged.
--
Cheers,
Lodger

[Espen Olsen]

The melt and disintegration of sea ice is well underway in Kane Basin and Baffin Bay, this can be watched using Modis images and do day to day flipping.

[Paul Beckwith]

@Artful Dodger

Exactly. In the past the much larger ice chunks clogged up the exit arteries like the Fram and the CAA. Now, the much smaller fragments just pass clean through the system. If someone can estimate the Fram exit volumes and compare them to the extent/area numbers then the difference will be a good estimate of the CAA ice flow-throughs...

Within a few months we will all be wagering on whether the ice is all gone in Sept, or Aug, or even July as opposed to the view of many now that this is not the year for total flush-out.

This year is a "regime-shift" in ice behavior. Absolutely no reason to not expect a "regime-shift" in the final result...how can the pack possibly survive the frequent, severe, long-duration cyclones that were ripping into the pack last summer when the ice still had some cohesiveness?

[Artful Dodger]

IJIS SIE reported for 04,03,2013 is actually the 2-day average SIE April (02+03)/2.

You ARE NOT calculating daily loss in SIE unless you also factor in the loss over the previous 2-day report (which covers 01 & 02 April). Only then can you solve for the overlapping day.

Additionally, we are lucky in that 2-day avg SIE changed only 4687 km^2 with the Apr 2nd report. This tightly constrains SIE loss for the single day Apr 3. Let's do the math based on the 2 day average SIE change to solve for N, the daily loss on Apr 3rd, 2013:

( 4687 + N ) / 2 = -210937

Solving for N, we get -426,561 km^2 as an approximation for single-day change in SIE for April 3, 2013.

Now you ask, is this credible. Short answer, yes. There are 3 large deep lows in Arctic peripheral sea right now:

• one on the Labrador coast, blowing onto the Labrador sea
• one in the Southern Aleutian archipelago blowing into the Bering sea
• and one in the sea of Okhotsk blowing onshore

Each of these areas sustained dramatic retreats of the sea ice edge during Apr 3rd. Make your own animation (with SLP or wind field overlays) with the IJIS Sea Ice Monitor.

Another prediction: if the winds are sustained (i haven't looked yet ;^) then any IJIS revision for Apr 3 will result in lower SIE.
--
Cheers,
Lodger

[Artful Dodger]

Paul Beckwith wrote | April 04, 2013 at 23:16

"how can the pack possibly survive the frequent, severe, long-duration cyclones that were ripping into the pack last summer when the ice still had some cohesiveness?"

Ooh, I know, I know! MAGICAL THINKING. Any sea ice that is transported South through Fram Strait automagically appears in Antarctica.

It's true because i heared it on Faux & Fiends. ;^)
--
Cheers,
Lodger

[Neven]

That high pressure area seems to be kicking ass again. I have a bad memory, but I don't remember seeing so many big high pressure areas (with that blue in the middle on the DMI SLP maps) in a row.

[Kevin McKinney]

Seems like a rip-roaring start to melt season. Not a pun on Neven's level, but I'll go with it, anyway.

[Peter Ellis]

Lodger: That's not how the averaging works. It's not that they get a readout once each day and then average two successive days together. Rather, they take all the swaths from the last 48 hours, combine that into one picture and then calculate the extent.

Some parts near the Pole will have been scanned dozens of times during that period, others will have been scanned only once - I don't think one day's data is quite enough to image the the whole Arctic, and even if scanned twice some parts will have been obscured by cloud in one or other of the scans. Moreover, the pattern of exactly which areas have been oversampled / undersampled on each day will vary from day to day. Trying to extract a "single day's worth" of data from the final product is absolutely futile endeavour, and would be meaningless even if you could do so.

[Ron Mignery]

The Fram is 500km wide. How could ice even tens of meters in thickness possibly jam in so wide an opening? Surely ice is not that rigid and uncompressible. Wipneus in an earlier post calculated that the volume of ice out the Fram appeared relatively constant with the speed increasing as the thickness was decreasing. The driver was apparently the prevailing wind and, unless that changed, the volume would likely not change. Of course that constant volume represents an ever-increasing percentage of the remaining MYI as it depletes.

[crandles]

Wipneus Fram export graph is at
https://sites.google.com/site/arctischepinguin/home/piomas/grf/fram.png

[Donald]

FWIW, I have been looking at the Fram each day using Worldview and calculating the speed at which ice is moving. For most purposes, you can use an average of 10 miles per day. It sometimes is more.

link - http://earthdata.nasa.gov/labs/worldview/?map=-1004160,-1844480,606592,-798976&products=baselayers.MODIS_Terra_CorrectedReflectance_TrueColor~overlays.arctic_coastlines&time=2013-04-04T12:00:00&switch=arctic

[Shared Humanity]

Crandles...interesting graph. It looks like April-June has really taken off. Why would this be the case?

[Wipneus]

PIOMAS update:
Latest value: 2013-3-31 21.612

I have updated my graphics at ArctischePinguin for the latest data.

Note that the graphics have been moved to a subdirectory. If anyone is using permanent links you will need to update these.

Monthly data
Daily Anomalies
Daily data
Daily data with a "prediction" based on exponential trend

[Wipneus]

PIOMAS update:
Latest value: 2013-3-31 21.612

I have updated my graphics at ArctischePinguin for the latest data.

Note that the graphics have been moved to a subdirectory. If anyone is using permanent links you will need to update these.

Monthly data
Daily Anomalies
Daily data
Daily data with a "prediction" based on exponential trend

[Wipneus]

PIOMAS update announcement in the spam box?

[Wipneus]

About the Fram export: there is a another monthly graph at https://sites.google.com/site/arctischepinguin/home/piomas/grf/fram2.png

[Tor Bejnar]

Sorry, Lodger, but I made no reference to, and implied nothing about, what had happened this past winter. I only reflected on the trend associated with the current wind map and forecast for the next few days for "thickest ice" (intending to mean >2 year old ice). In addition, a certain amount of the December 2 eastern bulge that is missing in your March 28 map moved westward to replace ice that is now in the Beaufort Sea.

The only thing I wrote that would definitely put crow on my plate (yuck, I'm a vegetarian!) is if the ice just above Greenland and the Canadian Archipelago moves as fast as ice has been moving in the Beaufort Sea.

I do appreciate your showing how much multiyear ice (at least 2 years old) north of Fram Strait has been moved this winter. Your map shows that there is now relatively little MYI in the area most likely to be exported during this melting season. As long as the Beaufort Gyre is supported by high pressure over the Arctic Basin, most of the remaining MYI will stay in the Arctic. The "goat's head", in my opinion, has roughly equal chances of getting exported or moving south, then west.

[crandles]

>"interesting [Wipneus fram export] graph. It looks like April-June has really taken off. Why would this be the case?

I am no expert but I would suggest:

1. Anomalous high pressure over Greenland observed since 2007. For causes of this I would suggest looking at:
a) Dr Jennifer Francis' work on meandering jet streams and blocking events and other related work.
b) Tedesco et al 2012 "identify persistent anticyclonic conditions over Greenland associated with anomalies in the North Atlantic Oscillation (NAO)"

2. Lower ice concentration allows faster movement of ice more than compensating for any reduced thickness.

3. Why AMJ? Perhaps more breaking up of ice in this period allowing the persistent anomalous high pressure to have more effect? I am really only guessing here.

I would expect that there could well be more effects than I have mentioned.

[A-Team]

Here is 78 days of Modis color visible imagery from last spring, March 30 to June 15 2012. Because the file size of a 78 frame animation is quite large, I cropped the size and dropped contrast while retaining enough to display crack development and open water.

Comparing 2012 visible imagery to 2013 infrared is somewhat problematic but the best match to today's date 05 Apr 13 is approximately 10 May 12, or 35 days later. The southern coastline in the vicinity of Banks Island provides the best diagnostic region.

Recall 2012 was a record melt year with a very similar arc fracturing pattern developing in the Beaufort. However this developed much later in the spring and did not extend past the Prince Patrick Island leverage point.

In summary, the rapid acceleration of Beaufort Gyre rotation in early June 2012 and the breakup of icepack into floes can be expected in early May for 2013. This will contribute to a vastly more extensive melt-out expected in late summer 2013.

[A-Team]

Steve B, that ice rheology paper from 2007 is a nice starting point -- folks were already very unhappy with the viscous-plastic model underlying all the IPCC models then and now.

Using google search on the full title pulls up all subsequent citing articles and just lately you can sort these to pull out the 2013's.

There are two free full texts (if you look around) -- one a 99 page book -- that seemed 'required reading' for understanding the fracturing and flow this year.

Or not. Richard Feynman viewed this as cheating -- better to shut the books, look at the data yourself and figure it out from scratch, as he did belatedly with SU(3), ie fractional electric charge, colored quarks and confinement.

http://192.95.52.196/wordpress/wp-content/uploads/2013/02/Paper5EarlyView.pdf

http://www.amazon.com/Drift-Deformation-Fracture-Sea-SpringerBriefs/dp/9400762011

Jerome Weiss Drift, Deformation and Fracture of Sea Ice
SpringerBriefs in Earth Sciences DOI: 10.1007/978-94-0007-6202-2.5

[Espen Olsen]

A-Team;

Did you notice the pre-fractures from the North into and between Ellesmere and Ellef Ringnes Islands? Worth to watch?

[A-Team]

Ron M writes. "volume of ice exported out the Fram appeared relatively constant [but] that constant volume represents an ever-increasing percentage of the remaining MYI as it depletes."

Right. Can one of our graphing gurus here can supply us with a Fram export volume chart that is normalized in this commonsense manner?

This would give us the leg up that Espen wants on mainstream downplaying of Fram export changes.

[Shared Humanity]

"volume of ice exported out the Fram appeared relatively constant [but] that constant volume represents an ever-increasing percentage of the remaining MYI as it depletes."

If volume export is relatively constant and sea ice is thinning across the Arctic, wouldn't this mean that 'area transport' through the Fram is increasing significantly? This should show up as an increase in the drift speed, right? Another possibility could be similar drift speeds but an expansion of the seasons where drift occurs. Are we seeing more export in the winter than previously? What are the implications?

[Neven]

PIOMAS post will be up tonight. Gotta run.

[A-Team]

Neven Acr writes "A-Team is not improving masterpiece paintings."

True enough. The person really posting the artwork here is R. Gates -- every comment a masterpiece of exposition. (My Birth of Sea Ice Venus was inspired by a 1486 painting by Sandro Botticelli, not a book cover as some thought.)

One way or another, Neven is creating a monumental resource here.

[HeisenIceBerg]

A-Team, you misinterpreted what Neven said.

[quote]When A-Team is not improving masterpiece paintings, he makes great animations.[/quote]

You applied the "not" to the wrong part of the sentence, interpreting it as "not improving", but it means "when you're not doing it". So what Neven means is that you are improving masterpiece paintings, but when you aren't, you make great animations.

[Kevin O'Neill]

HIB said: "A-Team, you misinterpreted what Neven said."

Yes, the first clause only makes sense if A-Team *is* improving masterpiece paintings.

An equivalent sentence would be: Not only is A-Team improving masterpiece paintings, he's also making great animations.

[David Vun Kannon]

OT, anticipating a new PIOMAS blog entry, what does "essentially ice free" mean in terms of volume?

[R. Gates]

I'm am preparing a longer post on SSW events, their causes, and their major impact on NH weather, but in the meantime, thought I'd share a few thoughts about the spring/summer Arctic melt now upon us. In terms of SSW and early season weather patterns for melt, I looked back at the past few years and the most similar recent year to 2013 is actually 2006. That year we had an SSW event that occurred nearly the exact same point in January as our event this year. Take a look at the 2006's & 2013's charts, beginning with temperature:

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_2006.gif

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_2013.gif

And then pressure:

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_HGT_ANOM_ALL_NH_2006.gif

http://www.cpc.ncep.noaa.gov/products/stratosphere/strat-trop/gif_files/time_pres_TEMP_ANOM_ALL_NH_2013.gif

2006's SSW event was more intense than 2013's, but we see that the long-term higher pressure that accompanies the SSW event was about the same. Also, during March 2006, similar to this year, we saw a very negative AO index much like this year, with nasty weather at lower latitudes that year in March, just like we had this year:

http://climate.umn.edu/doc/journal/snow060312_13.htm

and

http://www.nbcnews.com/id/10994127/

So what might this mean for the melt season? With the higher pressure over the pole, 2006's melt season started out very strong, but then faded a bit in August, preventing a new (at the time) record. See:

http://www.ens-newswire.com/ens/oct2006/2006-10-04-02.asp

As we've seen, 2013 has already shown signs of a strong start, and the ice is so much thinner than 2006. I do believe that the SSW events of 2006 and 2013 are similar enough to dictate the strong trend of the early melt season, but of course, weather variability, thinner ice in 2013, and another Great Arctic Cyclone or two, will most likely tell the story of the late summer melt and whether 2012's record will be beaten.

[Robert Fanney]

@ R. Gates

That's a good analysis. And I still can't keep my eyes off of A-Team's comparison of Beaufort ice 2012 with this year. For my part, I agree that early May / late April will be a critical time period to watch. A gateway, if you will, for another potential extreme event.

Been monitoring Nuuk Greenland temps. The hottest of the hottest spots for anomalous high temps at the moment. It's 52 degrees F there, about the same temp it is here in Gaithersburg, MD where I live. That temp is 26-28 degrees F above average.

Noticed most of the melt graphs showing more rapid melt as well. And the new PIOMAS volume measure is out. Shows volume on par with record lows in 2011 and 2012 for this time of year.

Barrow Ice Cam currently showing some 'blue ice' in the distance:

http://seaice.alaska.edu/gi/observatories/barrow_webcam

[Jim Hunt]

Robert - There may have been a hint of "distant blue ice" at Barrow on the 2nd, but I don't think there's any there "currently".

If you're into webcams revealing blue and/or white ice here's one courtesy of Silkman on the forum:

http://sermitsiaq.ag/icecam/

"Ilulissat IceCap right now"!

[Jim Hunt]

1. My latest comment seems have been consigned to "comment oblivion".

2. "Problems with the blog" seems to have been consigned to "blog oblivion". If I click the link I'm assured:

"Blog Not Found

The TypePad Blog () doesn't exist or it could have been mistyped."

[Espen Olsen]

Crane dance:

This is the time of the year when 1000s of Cranes are having their annual conference at Hornborgasjoen in Sweden, they are a bit delayed this season due to cold weather recently and bad winds from the south. Last years attendance was 26.500 in area not bigger than a few km.
But being there is a very impressive experience one will never forget, especially the intriguing and impressive sound of so many birds, I can only suggest anyone to visit the place if possible:

http://www.webbkameror.se/djurkameror/hornborgasjon/hornborgasjon_2_640.php

[A-Team]

Here is that same featured feature, but with slightly later dates -- 29 Mar to 06 Apr 2013 -- using Modis visible 1km resolution. The Bering Strait is not visible in this central Beaufort photo as it lies well off to the top.

Because of the satellite swath timing issues it is a good idea to measure translation and rotation from two completely independent imagery sources. Here again you can see the acceleration of the last few days quite clearly.

The movement is primarily rotational: 20.4º clockwise in seven days about a center pixel offset of (x,y) = (267,190), the red dot in the image below. This would not be unusual for the Beaufort Gyre, except for the remarkable angular velocity for early April.

Many earlier Gyre studies have associated seasonal rotational spin-up with thinning ice. The same weather gets a less massive object to move faster.

[A-Team]

Prior to annual ice breakup in the Amundsen Gulf, a Beaufort Sea shoreline fracture arc becomes established each year, stretching across the Cape Bathurst on the Yukon mainland to Cape Kellett on Banks Island.

The animation shows the 29 May 2012 blowout (day 148 in Modis imagery Arctic.20121148.terra.4km), followed a day later by collapse of the similar fracture line that forms each year across the McClure Strait between Cape Prince Alfred on Banks and Cape Manning on Prince Patrick Island.

The rest of the Canadian Arctic Archipelago channels were stable and did not melt until considerably later. Thus the breakup date of the Amundsen Gulf in 2013 will provide a marker for how advanced this year is compared to record melt year 2012.

As of 08 Apr 13 (day 98), both arcs have been stable. This season has been ~45 days in advance of 2012 since February, so if this continues, breakup of the Amundsen and McClure will occur already in April.

The animation begins on 08 May 12, pauses on 28 May just before the breakup and continues on to 13 July 12.