A-Team, a couple of years ago the trouble with PIOMAS for "civilians" was that it was only gridded - it was popular demand that led them to put out a daily single summary number. I don't know what "extra" information was released that Wipneus and Chris used. Perhaps one of them can explain what it was that was beyond the normal PIOMAS output. Or maybe it was just the normal output, but the latest batch for March. Erimaassa, maybe Neven is a fan of Eli. (http://rabett.blogspot.com/) :-)

Donald, presumably Nevin doesn't want to pay for a real security certificate (which is only really needed if you're doing commerce of some sort). As said (but perhaps not well explained) in the post above, you can either create an exception in your browser to accept this, or use http instead of https. Think of it like this: there are really three levels of security: http - no security, your packets can be read anywhere along the path they take. https without certificate - you get encryption. https with certificate - encryption plus you're guaranteed the website hasn't been spoofed (which matters if it's a bank, but who is going to spoof Nevin's forum?)

Scarlet (freeway blogger), I just wanted to say I've been a fan of your work for years. It's brilliant.

I looked at CT this morning and suspected this post might be coming :-) Wow, what a year.

Nares strait is an interesting case this year. Peterman (2012) is making about 1 knot southbound (has just entered Kane Basin) but sea ice doesn't seem to be taking the same flow. The path of the giant berg is presumably indicative of the main current flow, but perhaps there's a surface wind or wind-driven current going northbound. The polynya in the Lincoln Sea would then be in-situ melt, or just pushed clear, from that surface current. Its shape certainly reminds me of the "bubble" that a light fluid jet can blow in a surrounding medium.

At a rough guess, the albedo forcing from a 6 million sq km snow deficit for NH June would be significantly more than a 2 million sq km arctic ice deficit. However the snow deficit is shorter lived ... they are probably comparable over NH summer. Does anyone know if this has been well quantified?

I changed my CT vote down one bin, so I'm going for 2.75 now. Probably conservative as CT currently has 2.92(!)

I finally pulled the trigger on the August poll. 4.25 and 2.85, so I'm betting on two new records, but by small amounts. If a compaction event occurs I'll be quite a bit off though.

Kevin, that's a very engaging review you wrote. I found one tiny factual mistake you might want to correct - in the caption of the photograph of Barry Saltzman. Barry Saltzman died in 2001, at the age of 69, not in 1969.

Espen, Not just by kayak. I believe a guy named Henry Larsen made that same left turn in 1944 :-)

"Yep, the ground stays below sealevel all the way into central greenland basin. Similarly for ilulissat glacier" That topo map from wikipedia disagrees. It's very close, and the map isn't a very high resolution, but it's the highest rez map of Greenland's bedrock elevation I've seen. So, is there a well-substantiated source for sea level channels to the central basin?

With the arch broken, looks like Kane Basin won't take too long. http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r03c02.2012183.terra.1km

Thanks for that link Alberto. I was initially mislead by the first graph until I carefully read the captions of the first and second graphs to see precisely what they were showing. One caveat though - the second graph takes length of day into account, but it says "top of atmosphere", so the optical depth of the atmosphere may matter as WhiteBeard said. OTOH, scattering mostly just spreads the energy out - only a small amount is entirely back-scattered.

Another big drop in the CT area measure. Air temps, cloud cover and ice distribution *appear* favorable for a continuation of this trend for a few days.

The last couple of days of the IJIS graph have me hearing Tom Petty. (Free Falling...) It's still probably less than a 50% chance to beat the 2007 daily low extent, but pretty close to. IJIS Area is dipping under the 2007 line. Uni Bremen on the other hand has 2011 extent lower than 2007 for today. It's all within minor weather fluctuations, so all we can really say is that the death spiral continues.

Heh, just because yesterday I noted the IJIS area graph for 2011 touching the 2007 area and seemingly ready to cross it ... today it flatlines with zero change in area. Meanwhile IJIS extent seems determined to thread the needle between 2007 and 2008. Nonetheless, such low numbers in a year whose weather was nowhere near as favorable to melting as 2007's indicates further deterioration in the overall state of the ice.

Breaking: 2011 IJIS area falling below 2007 IJIS area. http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Area.png Not quite there yet, but pushing for a new record.

Twemoran, I agree on both points. Some days the crack in the Peterman is better resolved than others, but I'm not yet convinced it's widening. The Humboldt appears to be calving like crazy, with much of it coming from the side of that "bulge". When I look at the ice in Kane Basin, it seems to me that there's two bands of it - a western band made of sea ice that's come down Nares Strait, and an eastern band that appears to be mostly bergs calved off the Humboldt. Anyone else see it that way? Meanwhile Disko bay is pretty crowded with bergs from Jakobshavn Isbræ.

I'm trying to figure out in what situation 1.8 km would take 25 minutes by car. (Ok, the opening scene from "Office Space" comes to mind...)

Check out the ocean just north of Scandinavia. As in http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c04.2011226.terra and http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r02c04.2011226.terra I think it's a huge algal bloom in cobalt, azure and cyan. Cyan makes sense with cyanobacteria, but I didn't know that algal blooms could cause such dark blue colors too.

>That's been fast for decades, right? No, I'm wrong. Actually most of that was gone in mid Sept last year.

Oh wow, right you are - the very northern part of that region of fast ice. That's been fast for decades, right? I wonder if that will weaken the fast ice south of there. Another month of wear-and-tear on it at least.

Espen, are you talking about the fast ice (or ice shelf, not sure which it technically is) on the NE coast of Greenland? The seaward boundary of that ice has been remarkably stable (I've thought) but there's some interior breakup at the southern end now. Have you seen any recent changes in the seaward boundary north of there?

Chris, Thanks for that detail on thickness. I agree that even after the revision of PIOMAS it clearly implies lower average thicknesses than Cryosat, and most other data we have agrees more with PIOMAS than the initial results from Cryosat. Does anyone know in what timeframe we might see recalibrated Cryosat results?

North East Passage ... depends on your definition of "open". Looks like the contiguous ice has pulled a fraction back from the shore, but there's a lot of rubble in there. But the melt rate in the area has been tremendous, and the wind is offshore, so it may be truly open in a few days. Shallow though, not a deep water channel.