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Espen Olsen

Neven,

Better late than never! ;-)

Susan Anderson

Don't know how to post this as an image, but it might relate a little:

http://synoptic.envsci.rutgers.edu/site/sat/sat.php?sat=nhem&url=../imgs/wv_nhem_anim.gif

(too fast animation of water vapor circulation centered on north pole, with the usual void in the middle)

Jim Hunt

BBC Devon tell me:

"Thanks for your email. I have forwarded it onto one of the national science producers for consideration, I can not give you a name as it is an internal group email."

We shall see!

Neven

Better late than never! ;-)

That's my middle name, Espen!

Or maybe I should change my name to 'better late than Neven'. :-P

A-Team

A large black cloud system is moving up from the south, covering up crack system development in the Banks Island/Cape Bathurst area. (Darker means warmer in AVHRR infrared imagery.) I've attached the last good shot. This is presumably an aspect of the weather system you are referring to.

Meanwhile, the crack system has extended far to the north and east, in the form of ordinary fractures and an oblique shear, ultimately joining up with the dormant crack system above Greenland. This isolates the very oldest remnant multi-year ice above the CAA and Nares. It looks to me from radar animations that an immoderate amount of important ice has been exported out the Fram this month.

I wanted to document this event in part because of rapid image archive rollover. Beginning of the end, end of the beginning, or just a bad hair day for the ice pack -- we'll have to wait and see.

I agree with your point about the short shelf life of sea ice imagery -- in a couple of years, these will have the same interest as an ecological study of the dodo.

 photo BeaufortWarmCloud_zpsf2fa06dc.png

 photo BeaufortCrackExtension_zps18d4eef2.png

Espen Olsen

A-Team,

Yes the only solid open-sea sea-ice left in the Arctic is the relatively narrow band of sea ice above Canadian Arctic Archipelago and Robeson Channel, and how long will this last solid open sea-ice last?

Chris Reynolds

I'd forgotten there's still discussion here.

I've posted some animated gifs over at the sea ice forum.
http://forum.arctic-sea-ice.net/index.php/topic,35.msg723.html#msg723
They should go some way towards making the overall process driving the Beaufort event more clear. Although you may all have already worked out what the animated gifs show.

A Team - thanks for recommending Gimp.

Due to the time pressures of work/blogging (and necessary research)/sniping at denialists on Youtube, something's going to have to give regards the sea ice forum and the comments at this blog.

A-Team

Good question, Espen. And how much is really left now, where does it sit relative to the February crack system, how much of it is direct jeopardy of summer fragmentation, melt and export?

The image below compares Navy Hycom ice thickness with two ice penetrating radar satellites. While they agree rather well, where they differ I believe the radar has it right: separate instruments, multiple different wavelengths, agreement on a daily basis back to mid-Sept 2012. On older ice, the signal unaffected by bubbles, salinity, snow pack, columnarity and so forth.

The Beaufort crack system took place mostly but not entirely outside the older ice but now the shear is cutting into the green on Navy thickness. The older ice to the 'right' of the pole was displaced by younger ice and a massive crack system earlier in the month that also affected the northern multi-year ice.

What principle of physics will hold this isolated remnant of multi-year ice against the shore during next summer's peak melt?

 photo compOldIce_zpsae09662a.png

Espen Olsen

If this sea ice cracking process continues much more, we will see a record melt in the whole ice pack, the sea ice surface has increased by many times and this will result in increased melt activity much earlier than ever seen before. The over-nite scenario were the sea ice just disappear from one day to another is getting very close.
I cant recall seeing / watching the sea ice in this condition at this time in the season, remember we are still in February!

Chris Reynolds

I think it is highly significant that in ASCAT the fissure seems to come to a near halt when it hits the MYI.
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013058.sir.gif
This is no mere coincidence. The FYI that is modelled by PIOMAS HYCOM and DAM, and seen in ASCAT, is seriously thin! The high extent/area at present is not a reliable indicator of conditions in the pack.

For what it's worth I'm not sure I'd bet on next years minimum being above 2012's record.

Espen Olsen

North East Greenland,

Daylight at Jøkelbugt

Ice cracking report:

Cracks are already seen next to Ile de France and Shannon Island, this is almost unbelievable!!

http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl1_143.A2013059134500-2013059135000.250m.jpg

Chris Reynolds

Bearing in mind 'lurkers' I should qualify 'seriously thin':

I suspect that the peak thickness of much of the pack is now 1 to 2m max, the exception being the MYI core. Thermodynamic thickening as used in the models places a prob density centred on typically 2m with typical winter conditions. HYCOM has always seemed to give slightly thicker results than seem to be the case, and its saying the first year ice (most of the pack) is about 2m and above.

A-Team

Hey, this is great that Jim H and Chris have gotten onto Gimp animation. I heard that lisa.de has a better download with more commands ... plus GAP is available too (Gimp animation package add-an).

Chris writes on the forum that the oldest of the multi-year ice that Espen describes as hugging the CAA is still too thick to crack.

Here I investigated the latest on that with an Ellesmere infrared shot (Feb 28 20:18 10.8µ) which has far better crack resolution that ASCAT and other radar and drew out the cracks in Gimp, by inverting, colorizing, auto normalizing, and best of all, shadow-specific color balancing. I would say this displays bona fide cracks far better than the original grayscale.

The core of the core is still almost completely resistant but the last couple of days have seen significant erosion of the perimeter.

The image is 840 pixels wide so you need to 'view image' in your web browser to see what's being illustrated here.

 photo thickCracks_zpsd999d86b.gif

Chris Reynolds

A-Team,

Some cracking will occur in MYI areas, that's always been the case. But the largest fissures, visible in ASCAT seem to me to stop as they enter the MYI area.

Chris Reynolds

PS.

Check out the most recent ASCAT,
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/msfa-NHe-a-2013058.sir.gif

Look at how the arcs seem to act as if the MYI is a barrier. You see the same behaviour in summer in the enclosed channels of the CAA.

A-Team

Below I show what the crack system looks like at 250 m resolution in sub-micron light (conventional Terra RGB). If cracks -> floes -> more perimeter -> more melting and flooding by sea water, we want to know the full extent of cracking.

When using swathed imagery (eg ASCAT, JAXA-IJIS, Terra), it is best to look at a single swath because time differences can be large between adjacent swaths (half-day) relative to the intrinsic time scale of cracking (half-hour). Here I used cloud-free swath r05c02 of 25 Feb 13.

Using the 'measure' tool in Gimp for distances and angles between fixed landmark, followed by rotate, cubic rescale, and 'open as layers', our five types of satellite imagery and polar stereographic processed products (eg Hycom) over the crack system are easily brought into a common coordinate system stack. Not only do the native resolutions vary greatly (the number of pixels going up as its square), but what can be seen varies with wavelength.

For example, centimeter wavelength radar primarily sees surface roughness and sub-surface dielectric constant. Multi-micron sees surface and cloud temperature. Sub-micron wavelengths see the familiar visible. By lowering opacity in the layer control panel to semi-merge layers, it is instructive to compare what each satellite sensor sees or does not see.

The image below is again twice the width of what this Typepad column will display. I optimized the snowy Terra scene to bring out crack and shear details that are not so obvious initially.

 photo visCracks250m_zpsaf76d9ea.jpg

Apocalypse4Real

Apologies for the interjection, and not meant to change topic:

I have added the METOP 2 IASI CH4 imagery through February 28, 2013 pm to the webpage. I will add Google Earth later, time for work!

On February 28 am, areas of the Barents and Kara had CH4 concentrations as high as 2229 PPBv.

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

A-Team

Here's 1 km resolution for Terra bands 3,6,7 so visible plus infrared.

More or less the same region north of Banks Island as above but enhanced very differently. Gimp has a good system for naming and saving color manipulations, important if you want a consistent time series down the road.

The scan lines become a bit noticeable at 250 m resolution. A week of low opacity standing cloud waves shows up as bands of moderate periocity.

There is a trade-off between resolution and scene size. For our purposes, ASCAT and Jaxa-IJIS offer the best scene size but like 'Artic composite' AVHRR inadequate spatial and temporal resolution. DMI has great resolution around Greenland but small and distorted scenes. The sweet spot is the Ellesmere/Beaufort infrareds provided at cisclient.cis.ecdf.gc.ca

 photo 1km367bands_zpsd76fbb43.jpg

Espen Olsen

A-Team,

The piece of remaining MYI sea ice is now starting to disintegrate from above Banks Island towards Ward Hunt, look under Ellesmere Files!

Chris Reynolds

I see that the fracturing is now spreading along the coast of the Canadian Arctic Archipelago (CAA).
http://www.weatheroffice.gc.ca/data/satellite/hrpt_canarc_ir_100.jpg
But it's notable that it's far less organised than the parallel arc cracking previously. The largest new lead now seems to be a coastal flaw lead.

I've been pondering those arc fractures, and the bounding by the MYI region, as shown by ASCAT. The more I think about it the more I'm drawn to the conclusion that this pattern is indicative of the thinness of the FYI in Beaufort.

Espen Olsen

Chris,

I think it natural the fracturing is different when the cracks reach the MYI area, and it will be interesting to watch the area over the next couple of days, but it scaring the whole sea ice pack in the Arctic Sea is soon in a moveable mode!

A-Team

Oh yes, I am watching that unfold as it happens -- new 'Ellesmere' channel 4 comes in every hour and 14 minutes (61 of them before the archive is dumped).

The crack system has expanded into very thick multi-year ice. Right now (Ellesmere Mar 01 17:37), the cracks are directly north of Mould Bay, Prince Patrick Island, at 80ºN 120ºW.

I'm thinking the crack system will continue to move east, reaching Brock and Borden late today. Will it continue to Ellef Ringnes and Ward Hunt? I wish we knew more on the physical forces driving it.

If this continues, we are definitely experiencing Crackageddon. It may be a significant contributor to this summer's meltathon.

The image below is just the most recent. I have it animated but will wait a day or two on that for the event to play out.

 photo crackageddon_zps3de173e7.jpg

Espen Olsen

A-Team,

The "Perimeter" factor or increased sea ice melt surface will definitely be a game changer this melt season!

A-Team

Been meaning to thank App4Real for tracking methane and creating a research resouce archive on our behalf.

I've been wanting to look at this in a clean polar stereographic project with no land or lines underneath, for purposes of stacking it with other kinds of imagery.

Is there an easy way of making that (without degradation of data quality) from your kmz files?

Chris Reynolds

I'm still waiting for a new ASCAT image, but simply flicking between days 57 and 58 shows that the overall clockwise movement of the ice continues. And reference to Weather Central shows that the Arctic is now dominated by high pressure over most of the pack, with a low over Bering/Kara coasts - so net air movement is still clockwise.

Would it be foolish to wonder if once the ice is moving it's easier to keep going?

With regards a lot of the cracking you're seeing A Team, I'm afraid I'm back to wondering how unusual some of this is. Sorry to be so awkward after I was so wrong initially. I've definitely seen the 'pulsing' phases of pack movement in the past. This time however the net clockwise movement of the entire pack has caused the weird arc-fracturing (weird this early), that's what I think is abnormal. This wider cracking seems familiar, I'm sure I've seen similar response associated with opening of the Canadian Arctic Archipelgo's flaw lead (along the coast).

The problem is everything I had up to 2010 was stolen. During a burglary they took not just the lap top but the bag of backup dvds and various radios. And even full size QuikScat images won't help as small fractures never appeared on those.

We need years worth of IR images. :(

Some sources for any 'lurkers':
Weather
http://www.wetterzentrale.de/topkarten/fsavnnh.html - check out their archive back to 1998, good complement to NCEP/NCAR

Ice IR
http://www.weatheroffice.gc.ca/satellite/index_e.html

QuikScat Archive
ftp://podaac-ftp.jpl.nasa.gov/allData/quikscat/L3/byu_scp/sigma0browse/images/arctic
ASCAT Archive
http://manati.star.nesdis.noaa.gov/ascat_images/ice_image/

PIPS US Navy Sea Ice Model
http://www7320.nrlssc.navy.mil/hycomARC/navo/arc_list_arcticictn.html

Loads of datasets here, many of which I don't understand.
http://www.seaice.dk/test.N/
OSCAT is interesting

Espen Olsen

A-Team and Chris,

I think the next important crack in the area will be where there is a fissure starting from just west of Ward Hunt towards Beaufort and parallel with the coast, or more or less half of the fast MYI that is left now!

Neven

Gentlemen, please continue the discussion in the new post: The cracks of dawn.

Apocalypse4Real

A-team,

In regards to your kmz file request, you can attempt to manipulate the imagery in Google Earth as an "add image overlay."

I will try it and let you know how it goes.

A4R

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