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Nick Barnes

Look for good images of the QE islands from August or September in 2007.

Neven

Good idea, Nick, but I find those images are really hard to come by. Here's an image from the Uni Bremen archive, September 20th 2007, but that doesn't tell us much.

Lord Soth

I find the archive of the Environment Canada useful for historic ice charts.

I generally select the weekly regional color ice charts, select my area, and then dates.

You should then get two charts per week, One color coded for the concentration of ice, the other for the age of the ice.

http://ice-glaces.ec.gc.ca/app/WsvPageDsp.cfm?Lang=eng&lnid=3&ScndLvl=no&ID=11715

Of course, you will need to learn to read the ice egg cides. A quick overview can be found here:

http://www.ec.gc.ca/glaces-ice/default.asp?lang=En&n=84F6AA59-1&wsdoc=FE5C2688-21A8-4165-8FFB-5D28B2A1D943

Lord Soth

If you take a look at the north pole webcam, you will notice that the gap between the ice pans have increased, and their are now small flows that have broken off the larger ice pan.

http://www.arctic.noaa.gov/npole/2010/images/noaa2-2010-0725-070556.jpg

Kevin McKinney

Also--and I think this may have been mentioned--there are season-long animations of the sites available at the webcam homepage:

http://www.arctic.noaa.gov/gallery_np.html

Just watched the cam 1 movie; it's interesting to watch the development of the melt ponds, which happens quite late.

Century break in JAXA, yesterday, btw.

siili

Lots of action going on at north pole webcam #2, the big buoy in the forground is leening more and more for each new picture, and the middle floe with the smaller buoy on is not connected to the preasure ridge at the horizon since the edge e.g. close to the meteorological mast moves in the opposite direction. Also fast development of new ridges between the floes.

An extra fun part is to follow this in parallell with the usual denialist sites which are so exited about the cold temperatures from the DMI +80 temperature graph and that this is causing the meltponds to freeze over in the same picture heralding the coming of winter.

siili

Talking about the webcam #2 place, does anybody know where to find the data from the mass balance bouy in the images? In the usual army place, http://imb.crrel.usace.army.mil/buoysum.htm there isn't any data from 2010 buoy deployments like the one in the pictures. The only active older buoy is still reporting it's never ending journey back and through the Nares straight so the site is active.

At the deployment 19/4 the floe was measured to be 1,7 meters thick, which is about what the TOPAZ model gives for that time and place, and now that model gives about 0.6m thinner ice at the buoys, so it would be highly interesting to compare this with real measurments from the IMB buoy..

Nick Barnes

Five minutes turned up this one, which shows fairly clearly the extent of the remaining ice in the northern archipelago at the 2007 minimum. http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T072602015

Some other days around that date have fairly clear skies over much of the NWP, so if you want an image of a particular channel or island, go digging around.

http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T072451920
http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?T072741850

Neven

Nick, I did find this one straight away: http://rapidfire.sci.gsfc.nasa.gov/realtime/single.php?A072631750

But then I looked for 15 minutes and didn't find anything else. Either it was cloudy or the image was just outside of the Canadian Archipelago. So thanks.

If my eyes are not deceiving me (it's a bit harder to orientate myself than with the Mosaic images) 2007 had a lot of those waters between the islands void of ice. I find it difficult to make out if ice from the Arctic Basin was transported into the labyrinth. It looks a bit like it on that first image you link to, in the Peary and Sverdrup Channels, but it's extremely hard to make out for sure.

I'll go and look some more.

Nick Barnes

My recollection is that pretty much all the channels emptied out of ice right at the end of the 2007 season, but not in time for there to be any significant export from the main arctic ocean. In particular, what I remember is that the channels into the islands from the ocean are among the last to clear.

Neven

Okay so let's compare 2007 and 2010 at the current date.

If I compare the situation in 2007 (day 206) with yesterday's MODIS image (day 205) I see that overall it looks quite similar. When I zoom to 500m however, I think that currently there are more cracks in the Peary and Sverdrup Channels and the Prince Gustaf Adolf Sea. But the 2007 image is very fuzzy. so I'm not sure.

Nick Barnes

I would agree that the ice situations are pretty similar. 2007 was much clearer around Cornwallis Island.

Neven

It will be interesting to see if those Peary and Sverdrup Channels and the Prince Gustaf Adolf Sea clear up enough for the Arctic Basin ice pack to enter them. This time around we have nice, clear, flat images that can be used to make animations to see how the ice is moving.

Neven

There you go, Nick. You inspired me yet again for an animation. I wasn't even aware of it. :-)

Artful Dodger

Here is a AMSR-E Sea ice concentration map for the Canadian Archipelago on Sep 10, 2007. Not quite open in the Queen Elizabeth Islands.

Neven

Yes, but wasn't it open because there was still landfast ice blocking the ice floes or did the ice floes move in and clog things up?

I can imagine if things would speed up and all the landfast ice is gone come mid-august, you'd have a few more Nares Straits transporting all the older ice from where it would normally consolidate and thicken. Normally I would imagine that the landfast ice between those islands forms a barrier that plays a role in the thickening of multiyear ice.

But I'm a bit tired and when I'm tired my imagination plays tricks on me. Besides, we probably won't be seeing the opening up of extra Nares Straits for a weeks at the end of this melting season.

Artful Dodger

Neven: Do you have an FTP client with MGET? you can download all of Sep 2007 and animate to your heart's content.

ftp://ftp-projects.zmaw.de/seaice/NEAR_REAL_TIME/200709/Central_Arctic_SAR/

Poke around the other folders if you want more. IE: August 2007 is in /200708/...

Neven

Thanks for that, AD. This is from some German university, right? I believe they had a minimum sea ice extent projection as well.

I've quickly made an animation, but it doesn't really answer my question. It looks a bit as if ice is transported south, but it could also be sea water refreezing. I think such a thing would be most visible on satellite images, but it's impossible to make an animation from 2007 MODIS images.

The animation looks cool though, because 2007 was so awesome. It's like a huge bite was taking out of the ice pack, with just a strip of ice reaching all the way to Novaya Zemlya and the NWP completely free of ice. 2010 is starting to look a bit like that in a way.

Artful Dodger

I think the most important issue is will there ever be alternate exit points for sea ice to leave the central basin through the Archipelago. I don't know. It seems to me that the reason Nares Strait exports ice is because there is a natural outflow of water from the Lincoln Sea to Baffin Bay. So the question becomes, is there a natural current that flows south through the Queen Elizabeth Islands? Or, will a current appear if the fast ice disappears? Just 47 shopping days until Sep 10...

Neven

I coincidentally found an answer to this question on this NSIDC Arctic Sea Ice Report from August 18th last year:

Recent research by Stephen Howell at the University of Waterloo in Canada shows that whether the Northwest Passage clears depends less on how much melt occurs, and more on whether multi-year sea ice is pushed into the channels. Counterintuitively, as the ice cover thins, ice may flow more easily into the channels, preventing the Northwest Passage from regularly opening in coming decades.

So yes, multiyear ice can disappear from the Arctic Basin like this, through those other Channels and the Prince Gustaf Adolf Sea. If it happens this year, I'm sure to be saving the images.

I'm not sure about the blocking of the NWP in coming decades though...

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