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me.yahoo.com/a/nSjChi4X3vr8X3DRw93GkY1.cerja.8nvWk-

I am far from a global warming denier. You can look at my other posts.

I believe in following the facts though. Nobody on this forum predicted we would have record volume gain this winter. This is an unexpected fact.

Hardly unexpected, it was virtually inevitable following a record minimum! Failure to do so would have severe implications for this summer.

Phil.

Espen Olsen

Phil,

I agree with you, when record lows of any kind are registered, gains will follow, pretty logical when it comes to the Arctic, at least for the near future!

Dave C

Kevin- 2012 was lower.

For those keeping track, 16.4 in 2008 was the previous largest volume gain through March 1st. This years volume gain has been 16.7 through March 1st. As we all know, 2008 was the only year this decade with a volume recovery, finishing 600k km3 higher than 2007. Winter ice gain has a large effect on summer minimums.

As for why I think the cracks won't result in as much loss this year- When ice cracks during the winter this opens up water and results in even more ice. We clearly saw this February. We still have another month for ice to gain even further. Volume peaks in April.
It seems that the most likely mechanism for cracks resulting in melt would be increased ice transport. But these cracks are a long ways from the fram strait or eastern edge that ice mostly gets transported to. Also, ice transport by volume through the fram has been remarkably steady over the years.

It's possible that there will be record melt this summer to counterract the record ice gain, but I don't see any strong theoretical reason to count on it.

Supertuscan

Where o where is the Goat's Head? Is this a section of MYI that is migrating near the Pole? Is this a term coined on this site?

Espen Olsen

Dave,

Read my previous note.

Neven

Gentlemen, hold your comments. PIOMAS post will be up in a minute.

Apocalypse4Real

One item of note: The SLP currently over Kamchatka is now anticipated to move over the CAB in the next three days - a true polar low - and exit near the Fram. It is bringing warmer air with it into the Arctic Basin.

http://polarmet.osu.edu/nwp/animation.php?model=arctic_wrf&run=00&var=plot001

While the ice will certainly thicken, the impacts of continued lows may weaken it for later melt. Time will tell.

Espen Olsen

Baffin Bay, Greenland,

Heavy cracks are now seen along the the coast of Greenland:

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r03c02.2013071.terra

Neven

Given the high temps in the Baffin Bay area all winter long, I'm expecting a fast melt and high SSTs there, possibly with similar consequences for the GIS.

A-Team

[She's taking the Prius into the dealer, nobody's home to monitor computer useage!!!]

Don't miss the Big Event arriving Sunday March 17th, according to the Navy ice speed and drift forecast!!! The overlay below shows the ice coming down hard and fast from the north on last relic ice refugia -- this will be a compression event, unlike the extensional tension on the Beaufort. Will the ice pile higher and deeper or just squeeze out to the sides like very cold toothpaste?

We actually don't have an exact handle on timing because of satellite swath assembly and separate processing and release delays for each map or image, plus hairline cracks not showing up immediately, so let's say the 18th or 19th to be safe.

I've got the Navy animations teased apart now by a circuitous procedure that isn't worth describing because it won't port to other platforms. The vector arrows are too thick really but being straight black, they can be selected and made transparent or translucent so that the imagery underneath is not obscured. Since the Navy uses color to contour up regions of high and low ice pack velocity, I decided to use a grayscale Ascat radar base so as not to have competing color schemes.

Arctic maps and imagery in polar stereographic projection can been done very accurately by taking the longest common distance on between two features visible on both, typically the south shore of Chaunskaya Bay across from Pevek, Siberia to the spit of land NW of the ruins of the Reykjanesviti lighthouse in Iceland.Note the North Pole is not on the intersections of diagonals so the rotation needs to be offset to center at coordinates (411,447). When an Ascat base layer is brought in, it will need a small offset (compare the coordinates of the tip of Banks Island).

To overlay Navy Hycom products on imagery, scale up and rotate by:

Ascat radar 122.30% 45º
Jaxa radar 109.61%
Arctic Composite IR 336.72%
Beaufort IR 910.72%

Map trivia? Yes and no, it depends on whether you want a StackBuilder cgi that puts it all out of sight, for everyone.

 photo BigEvent17Mar13_zpsec116864.jpg

A-Team

Supertuscan, the goat's head is a stable, easily recognizable block of older thicker ice that is being used to precisely track motions and rotation in the central Arctic over the last few years.

You can see two white pale horns a quarter inch above the north pole in the image above. In some configurations, it looks more like a pinwheel, or lately, a kangaroo.

This block of ice is peripheral to the main relic older ice, not strategically important. The name doesn't matter -- what matters as that it persists as a (not strictly) rigid block, rather than undergoing constant pizza dough deformations like the main near-coastal older ice.

I'm getting to the explanation. But first recall Joe Romm and his admonition to use extended metaphors for effective scientific explanation.

Rubber sheet motion and materials failure (fracturing) are very complex to describe. Rigid block are easy.

Thus the goat's head is the place to start for ice kinematics. Which is the place to start for ice dynamics. Which may be more important now to summer melt than in the past.

So it's all about the camel getting its nose under the tent. We ruminate here quite a bit on the future of Arctic sea ice. So the coming extended metaphor is strung on artiodactyls.


A-Team

Here is the Big Crunch anticipated for 17 March 13, hopefully to show up in crack pattern by March 19.

Black arrows show Navy-predicted ice drift and speed; grayscale image is Ascat radar, orange is higher resolution Ellesmere 10.8µ infrared.

The outlined goat's head will be moving poleward but this is incidental to the main ice compression event.

 photo NavyOverEllesmere2_zpsb0ff89ee.jpg

Andy Lee Robinson

Here is a new Arctic Death Spiral

http://haveland.com/share/arctic-death-spiral-1979-201302.png

February average is still lower than last year, in spite of the welcome regrowth.

Kevin McKinney

Hey, that 'death spiral' is pretty good... Dr. Serreze's famous comment has launched quite a few graphs now.

Shared Humanity

A-Team..

Looking at the image of Navy-predicted ice drift and speed, it seems some of the effects will have to be compaction along the CA. Could this help some of the MYI to survive the coming melt season and build in the next freeze season?

johnm33

Following up to my previous comment above, it took about 20 days last year from the beggining of signs of [imho] bottom melt at Banks island until there was an opening formed between there and Mackenzie bay, given this is much earlier in the [melt?]season lets give it 30 with nuetral weather so around the 28th+/- but before the 10th of April even with unfavourable weather until we see the same this year.

A-Team

Shared H, yes compression could result in ice ridges or over-thrusting, resulting in thicker compacted ice there. Ice ridging is difficult to observe. The best shot at that was a couple of weeks back with Modis visible seeing shadows from nearly horizontal sunlight very early in the day. The ridges are only tens of meters wide whereas fractures can grow to tens of kilometers across.

Actually, the motion vectors really suggest only a tiny triangle of compaction with the main body of old ice splitting in two, the eastward portion moving along the shore to the Fram and the westward half moving towards the melt zone in the Beaufort.

The event is still 4 days off -- heavy black (warm) clouds are moving into the area. So the first issue is no surface visibility at all with visible or infrared imagery and radar not quite having good enough resolution. Fracturing is continuing as we speak, so the second issue is the status of the ice at the time the compression event begins.

I put the March 17th Navy over a March 13th infrared Arctic Composite. This shows the cracks fairly well relative to the predicted downward ice motion. The image extends off Typepad over to the Fram.

 photo navyonAC2_zpsa80682a3.jpg


A-Team

Johnm33, have you been following the Nares as well? It looks to me like something has changed over there in the last couple of days. Melt coming up from the south. The Nares has a long observational record and there is all kinds of high resolution imagery for it, so it is favorable for year-to-year melt onset comparision. I

I've attached some 12-13 March infrared imagery, newer ones at the top. The three lower rows represent channels 4,3,2 so they could be combined -- perhaps informatively -- into single color images.

 photo framMelt_zpsad415ace.jpg

Artful Dodger

Hi A-team,

(lot's o'crickets in 'ere, wot? ;^)

Here's my comments on AMSR-2 regular observations and the Spinup plan, from Aug 10, 2012:

http://neven1.typepad.com/blog/2012/08/arctic-summer-storm-open-thread/comments/page/1/#comment-6a0133f03a1e37970b0177440bf9c9970d

It's my opinion that significant ridging can only occur in MYI, which has the mechanical strength to resist further breakup, and the thermodynamic energy content to resist melting.

Specifically, when new salty sea ice is subducted, it melts down to the level of the old ice keel. First year ice can not grow much beyond its thermodynamic equilibrium depth.

Good work on the new gyre images. Thanks!

Cheers,
Lodger

Neven

A-Team, I thought I had a blog post with a comparison of Nares ice arches in previous years, but can't find it (should've given it a category of its own, silly me). Of course, there's the Nares expert blog from Andreas Münchow: Icy Seas. And the imagery on his university work page.

Neven

BTW, I expect that ice arch to hold until June at least.

Found the images of previous ice arches on my hard disk. Don't know what date though, but I guess it's about the location and shape of the arches.

2003


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Apocalypse4Real

I have updated the METOP 2 IASI CH4 imagery from March 5-12. Almost each 12 hour report has recorded concentration levels about 2100 PPBv, in some parts of the imagery.

There has been a significant amount of release activity in the Norwegian, Barents and Kara Seas. As fracturing has occurred in the Laptev, East Siberian and Chukchi Seas, there are spikes of methane as that trapped under the ice leaks through.

In the last few days, areas with thawing also reveal higher levels of methane for short periods of time.

Finally, Antarctica has a cloud of higher concentration of methane (above 1890 PPBv) that has been spreading over a larger area.

I have attached three Google Earth overlays to give an idea of dispersion and concentration of CH4 during the last few days - in the Arctic Methane Release thread on thr Forum. These represent only a single mb layer of methane within a 12 hour period of concentration. The whole series of 586 mb and 718-742 mb GE images will be added to my website by tomorrow.

https://sites.google.com/site/a4r2013metop2iasich4co2/home/2011-airs-ch4-359-hpa-vs-iasi-ch4-970-600-mb

A-team, your image wizardry continues to educate and inspire me. Thanks for all you are doing for observing this incredible winter/spring season.

One more thing, yesterday on the Ellesmere imagery there was not only plumes, but some of them were dark - meaning heat release from the fractures above Borden Island. I'll post an example on the Forum.

Artful Dodger

Hi Neven,

A quick Google finds your Jun 17, 2011 post:
Nares Bridge is falling down

Cheers,
Lodger

johnm33

A-Team fwiw my view is that the retreat of Nares from the south is due to the pressure of PW/AW? from the north undermining the ice as it breaks through, that means it would have to be very energetic at Lincoln, which predicates a rapid thaw of the whole channel, and even as I say it I don't believe it, but can't think of a plausible alternative. If it was coming from north of Banks is.through to Devon is. you'd think it'd be exhausted likewise through Nares but from where to the south? zero possibilities. So on a balance of probabilities basis I'd guess PW halted by the thick ice of the pyramid turning south.
But don't quote me.

Neven

Thanks, Lodger, I did manage to find that one, but I was actually looking for those ice arch images. Some of them are from Patrick Lockerby's blog, some not, can't remember, didn't label properly either.

Apocalypse4Real

I have updated the IASI and AIRS/Giovanni CH4 imagery through March 13, 12-24 hr.

According to Dr Yurganov, the CH4 readings in the Norwegian and Barents seas are the highest recorded by IASI.

See:
https://sites.google.com/site/apocalypse4realmethane2013/home

Neven

To all members of Crackheads Anonymous: There's a new blog post dedicated to the cracking event. Please continue the discussion there (or on the ASIF).

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