Animation 3: Beaufort Sea

This post is a combination of several things. First of all, I wanted to make another animation of some part of the Arctic, because things have been changing a bit faster lately. Second, I've been planning to write a piece about the Beaufort Gyre for a while now, except that I cannot bake a whole blog post from it. Third and last, in the comments we had been discussing those huge swathes of red, yellow and green (and even a bit of blue) on the Cryosphere Today daily ice concentration animated map that have been showing up and disappearing again in the last two weeks. Some people remarked that this most probably had to do with melt ponds that more or less distort the reported ice concentration picked up by the satellite sensors.

So, let's start with explaining what the Beaufort Gyre is. The Lord praise the man who invented copypaste and also Ole Nielsen, who has written an excellent informative synopsis on his weblog:

The Beaufort Gyre is an ocean and ice circulation pattern in the Beaufort Sea, north of Alaska. I have marked it with a B on the map. This gyre moves in a clockwise direction. This circulation results from an average high-pressure system that spawns winds over the region. Ice that forms in or drifts into the Beaufort Gyre has historically remained in the Arctic ice system for years, accumulating snow and thickening each winter. Beginning in the late 1990s, the ice began melting away while in the southern parts of the gyre, before completing the circulation.

The short story is that Beaufort gyre is a result of the Coriolis force, the prevailing winds, and what is known as Ekman transport (in short: movement of water at a certain angle to the wind).

In Patrick Lockerby's latest piece, Arctic Ice June 2010 - Solstice Update, there's a recent picture from the MODIS Arctic Mosaic. As Patrick writes:

Ice color is a fairly good indicator of ice condition if the image resolution integrates polynyas and meltwater pools so as to make the ice look bluish-grey. The image below shows whiter ice within the circle and bluish ice outside of it. The Arctic mosaic images show the bluish-grey areas as highly fragmented, mobile and melting ice. That rotten ice probably won't last long. I give it 4 to 6 weeks.

I suggest that you have a look at some of that rotten ice in the Rapidfire images and then compare what you see with the following Cryosphere Today image.

So here's where my animation comes in. I've decided to concentrate on the MODIS Terra 1km True Color image (r05_c03) that shows the big polynya off the coast of Barrow and a big chunk of the eastern part of the Beaufort Sea. The animation shows the past 3 weeks, from June 3rd to June 23rd. Here it is (click for a larger version):

 

The first thing to notice of course is the Beaufort Gyre in action. This has already made the making of the animation worthwhile, but there's more. If you focus on the upper left corner you can see these huge ice floes being moved and then broken up by the Gyre. In my opinion this looks kind of spectacular, just like that block of ice that blocked the Nares Strait for three minutes and a half. Furthermore, you can see two even bigger ice floes in the middle left of the picture that also seem to be in the process of being shattered into a million pieces.

And last, but certainly not least: You can clearly see the ice mass changing colour around day 159 (June 8 2010). Now compare that to the same date on the Cryosphere Today 30 day animation. The colour in the animation gets a bit darker, but doesn't change much after that. On the CT animation you see that huge swath of red, yellow and green revert back to pink and purple. Could it be that the sensors get tricked by the ice changing colour and getting darker, and that this then is accounted for the following days?

Anyway, I hope you like this newest animation. I'm hoping the Siberian side of the Arctic becomes a little less cloudy for my next animation.

Comments

[Greg Wellman]

I'm strongly of the opinion that both CT and Bremen are short-term "fooled" into showing newly blue ice as a lower concentration. I think they then apply some sort of correction.

[Lord Soth]

To diverge on your copy-paste, this originated from the term cut and paste, and goes back to the days of PDP-8's and paper tape.

In those days if you had a bad line of code, you would physically cut the code out of the paper tape and paste (scotch tape) the new line of code, as it was the quickest method.

So the term cut and paste was invented.

http://www.science.uva.nl/museum/papertape.html

I still have some rolls of paper-tape in my office, which shows how much of a packrat I am.

Sorry for the Nostalgic flashback; Now back to the crisis at hand.

[Neven]

Crisis? What crisis? ;-)

Thanks for the history class. I always wondered about 'paste'.

[logicman]

Cut-and-paste originated about 1500 with the 'commonplace book' - later know as a scrapbook. The method was later used in the printing industry to make mock-ups of pages prior to type-setting - long before the computer, or even the wireless transmitter and the kinematograph. ;-)

Patrick Lockerby
http://www.scientificblogging.com/chatter_box/

[Peter Ellis]

Even prior to 1500, it was in use in the culinary industry, with the manufacture of multiple identical shapes from dough. This so-called "cut-and-pasta" method was subsequently taken over by the scrapbook community, the paste itself being made from the overcooked remnants of the meal in question.

(P.S. Can it be Friday yet?)

[Kevin McKinney]

"Can it be Friday yet?"

Hell, no, don't rush me--I have Thursdays off!

[Glacierchange.wordpress.com]

This is a brilliant animation. There is alot to see here, it is the expansion of ponding that most catches my eye. The hard thing is to ignore the clouds. For those interested in the Beaufort Sea Gyre Woods Hole has an ongoing project providing good background data. Take a look at some of th historical model data on circulation extending back to 1952.

[Glacierchange.wordpress.com]

One other point this sea ice diminishing corresponds to the glacier retreat in the area most proximal to the Beaufort, the Brooks Range. Note the changes in Okpilak Glacier, observed by Matt Nolan, UAF.

[Neven]

Thanks for that link, Glacierchange. If we get into record territory towards September it will be interesting to have a look at what this might mean for glaciers on Greenland and surrounding the Arctic ocean. I'll be sure to ask for your advice when that moment comes.

[Glacierchange.wordpress.com]

I wrote a piece for Realclimate two years ago focusing on the Petermann Glacier . This glacier due its very thin floating terminus tongue and very large floating section is uniquely vulnerable to sea ice loss in Greenland. From the 30 day animation you link at CT it looks to have gone ice free this week. Thanks for all the thought provoking work.

[Artful Dodger]

Thanks for your continued great work, Nevin.

There is an excellent YouTube animation based on MODIS true color images showing the Beaufort gyre. It is titled "Arctic Sea Ice Melting 2010" available here:

http://www.youtube.com/user/noiv#p/a/u/0/a8GHCrMmPtY

The spin of the Sea Ice west of Banks Island beginning day 150 is remarkable (look West of the NW Passage).

[Neven]

That's a very nice animation! Especially as you can watch it full-screen in HD (which is not possible with the GIF animations I upload here). I'll link to it in my next animation post.