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Espen Olsen

Wipneus;

Very nice map, a the png file is a better file format than the JPG, the latter is best for real photos.

Ostepop1000

@ Stephen Pekar:

I think what we are seeing there is the eye of the polar cyclone moving across the ice. The ice is stressed by the enormous forces and starts thinning as ice is moved out from the center towards the edges, creating what seems like thinning.

Actually, as long as the eye of the cyclone is positioned in such a cold area close to the pole, this could mean that more ice is being formed. The thinning is being constantly filled by newly formed ice, which is constantly transported outward.

It is an ice making machine.

Now if the centre of the cycklone moves f.ex towards the Siberian shores where there has been mild temperatures, we could start to see some real breaking up and melting, but nothing indicates this is about to happen as there is a persistent blocking high in those parts at the moment.

SteveG

Two comments on the current state of the arctic ice cover:

First, the NH snow cover anomaly has now fallen below the long-term mean - and by using the HI-RES MODIS (250m) imagery, it's quite clear that the ice concentration is lower than almost all 'charts' & 'graphs'seem to be depicting.

There are a number of locaions where ice cover is shown on the 'charts' - but close examination of imagery shows there is considerable sea fog fooling the sensors. (Surface temps over the arctic ocean clearly point to advectionb fog situations in some areas as well.) In other areas, low clouds induced by cold air aloft and a low level inversion are also causing some sensor mis-interpretations.

'Blue ice' as seen in higher REZ images that has appeared over the past week over portions of the arctic ocean (similar to the appearance taken on by the still frozen inland lakes) also supports either no snow cover or very little, atop the arctioc ocean ice.

Sometimes, we seem to rely on way too many algorithms and 'sensor interpretations' for what is going on when a close-up examination of VIS imagery can tell a more complete story. Not unlike operational forecasters who fail to 'look out the window' before issuing their forecasts.

Steve

A-Team

The Navy Hycom 30-day links are a rolling target (unstable link). Below I captured their anticipated Big Thin as projected out to 06 June 13 (and who knows where the event will end up).

Basically a very substantial area of 2+ meterish ice is thinning down to 1+ meterish and below (but not to open water).

Their palette of 5 cm increments in thickness is hard to visually resolve, much less to put a number on, so I included it along with a 32-step grayscale.

So, left as exercise in geospatial quantitation, select a thickness via your PS/ImageJ/Gimp color picker with radius maxxed out per each palette square, then replace with a gray, then tile out into layers with guide lines and 'guillotine', then use 'grain merge' on each day to subtract and renomalize to neutral gray for no change, colorize thinning as reds, thickenings as blues, numerically integrate net daily volume loss, save as slow animation and table.

 photo navyJon06_zps5b3956c3.png

Chris Reynolds

John Christensen,

On my list of things to do is to re-read the papers on the 2007 event. IIRC the papers restrict themselves to 2007, although conditions leading into 2007 may have been discussed in a paper by Zhang.

As far as I can remember the consensus is that 2007 was driven by the atmosphere, and an unusual AD pattern. But 2006, and the role of the AD in summers since 2007 keep making me wonder whether the ice was driving the atmosphere. Bluthgen offers some clues that this may be the case.

Chris Reynolds

Bluthgen et al.
http://onlinelibrary.wiley.com/doi/10.1029/2011GL050486/abstract

I have a pdf if you need it.

Bob Wallace

Stephan - the predicted thinning could be the result of the ongoing storm being discussed.

Over on the forum Artful has an interesting piece on Ekman pumping which is likely the physical process which would cause rapid ice loss in the storm area.

https://forum.arctic-sea-ice.net/index.php/topic,92.200.html

A-Team

Fantastic work there, Wipneus.

Below I captured the area north of 80ºN shown above in the Navy Hycom series (26 May 13 ~ corresponds to the bottom half moon). One or the other had to be rotated; 90º is a safe matrix transpose but 45º is, as you say, bad.

From the embedded histogram (Arctic Basin in the original image), very little use is being made of the 256 available shades of gray. Contrast-stretching in imagery amounts to multiplying by a constant in the R world so that all the values fall between [2-254], reserving a few shades for other purposes.

For consistent animations, the contrast stretch has to stay the same over various days (a limitation over the long term); other than that it improves the image safely (reversibly, does not degrade information).

It appears that the Big Thin predicted by the Navy is actually taking place. If so, would be good to document the event here on Neven's blog in quasi real time.

So if you are able to make similar pngs for 27 May on, I can do the masking, cropping, uniform contrast stretch, and animation.

Image width 699 pixels; 415 showing:
 photo Navy3125B_zpsf3c19819.png

Kevin McKinney

Chris Reynolds,

Thanks for clarifying those table values! Appreciated.

Chris Reynolds

No problem Kevin,

I assumed when PIOMAS was mentioned everyone would know the units. Mea culpa.

Boa05att

New paper just out on links between 2007 minimum and extreme weather:

http://onlinelibrary.wiley.com/doi/10.1002/joc.3723/abstract

Neven
It appears that the Big Thin predicted by the Navy is actually taking place. If so, would be good to document the event here on Neven's blog in quasi real time.

I'm opening a blog post in the next hour...

Bob Wallace

A-Team, take a look at their concentration maps. The area of focus seems to move from 80%+ concentration on May 27 to 50% - 60% concentration on June 6.

There's open water around the remaining hunks of ice.

Just Testing

Re IJIS and upward revision for the minimum:

I'd like to point out that there's an apparent inverse correlation between this date's extent and the minimum. The extent for this date being high would be a reason to adjust downwards.

Chris Reynolds

Boa05att,

Thanks, that seems to be relevant to what I was saying earlier about 2007. The abstract isn't very persuasive though.

Robertscribbler.wordpress.com

Looks like we have three major upwelling events since 2012.

1. The Great Arctic Cyclone of 2012.
2. The Great Crack-up of February and March 2013.
3. And what appears to be upwelling thinning ice in the Central Arctic now due to a persistent cyclone in the region.

GreenOctopus

GFS seems to suggest the cyclone shifting towards the CAA in the next week during its final days... with the bulls-eye of about 990 mb directly over the MYI?? Meanwhile, we see highs appearing over the Siberian side, suggesting the sun will swing by to clear out the ongoing storm wreckage like a push broom.
http://www.wetterzentrale.de/pics/Rhavn1201.gif

Just wow.

John Christensen

Chris and Boa,

Thank you very much for the articles. Will need more time to review.
I found this interesting article also on 2007 discussing a case of rapid bottom-melt:
http://onlinelibrary.wiley.com/doi/10.1029/2008GL034007/abstract

Neven
Just wow.

You can say that again, GreenOctopus. It seems the highs are then replaced by an even more intense cyclone (980 mb) over the same spot it is now. At least, that's what the ECMWF forecast says.

Which is why this whole event has a post of its own: If this is real...

Al Rodger

Rutgers Uni have just updated their NH Snow Cover numbers to week 22. 2013 had just got its nose ahead by mid May (the calculation of the anomaly used on my graph has a small error it seems) but over the last 2 weeks has gone less melty and fallen back. Thus the strong trend for less summer snow seen over the last few years could be taking a year off.

Neven

Rutgers have also updated their monthly anomaly chart for May. 2013 is third lowest (after 2012 and record year 2010), which means there has been some pretty impressive melting in the past month, given the fact that April 2013 had the first positive anomaly in 9 years.

Henry1

It appears PIOMAS updated. 2013 has managed to bump above 2011 and 2012 now with the slow start.

http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2_CY.png

John Christensen

Looks like the cliff was just raised half an inch..

John Christensen

Neven,

I look forward to the next PIOMAS update.

Since the daily volume has improved, it appears conflicting that the monthly anomaly and trend has moved further away from the average.

And the cyclone has returned from CAA to the Pole..

John Christensen

Section for curious news:

First time ever that Pyrenees have offered skiing in June:

http://www.adn.com/2013/06/01/2923211/pyrenees-slopes-open-for-rare.html

More extensive use of snow machines are part of the story, but still another sign of anomalous weather.

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