Arctic Sea Ice

Arctic Sea Ice Forum

The Arctic Sea Ice Blog is close to reaching the 25,000 comments-mark. Thanks to disappearing sea ice and great interest therein the blog was off to a flying start right from the very beginning, with traffic peaking last record melting season (especially when the cyclone hit).

There is a clear correlation between blog traffic and what happens in the Arctic. I guess when we hit 1 million pageviews a day, sea ice area/extent will have gone below 1 million km2. ;-)

This, of course, is great, as one of the reasons I started the blog - aside from personal interest and getting a knowledgeable community together - has to do with the philosophy of limits to growth. If AGW is a serious event (I think it is), it will constitute a very hard limit that just cannot be denied, except by the you-know-who. The Arctic is at the forefront of AGW, so this is where it all starts. And the more people are aware of it, the better, if not merrier.

But there's a downside to every upside, as Johan Cruijff is wont to say (in the picture on the right).
As more eyes start to see, more mouths start to talk. However, Arctic sea ice decline and its consequences make it difficult to stay on-topic.

Together we jump from the subject at hand to AGW in general, to solar power, to CT global SIA numbers, to methane burps, to booms with or without the sonic, etc. All of this is only logical, but the noise can become too much, especially during the melting season.

It makes it more burdensome for me to keep track of everything, and it also makes it more difficult to find those interesting and inspiring tidbits observed by one commenter or other. I've already spent many hours looking for something someone had said perhaps only weeks earlier, but not knowing which thread as it was off-topic. That can become really annoying.

I figured things would run much more smoothly if there was a separate forum where people can open topics themselves. And so with the help of an early commenter and the feedback of several others I've set up the Arctic Sea Ice Forum, that together with blog and daily graphs forms the holy Arctic Trinity.

Mind you, on advice of security manager Lodger I'm linking to the forum that has https in front of its address as this makes the forum much safer to use (as explained here). Your browser will come with a warning about security certificates, so make an exemption for the forum as the https actually makes it more secure, or if you're not comfortable with that, just remove the 's' from https or go here.

In this Arctic Sea Ice Forum it's possible to discuss everything you like, from Cryosphere (Arctic, Antarctic, GIS, glaciers) to AGW in general and climate policy. It also makes it possible to start your own polls. At the bottom of the page you can choose to be notified of new threads and comments. You can post images that will be re-sized to 660px when bigger. There are probably many more functions I don't know about yet, which is why there's a section where you can comment on the forum itself.

This doesn't mean that you can't comment on blog posts on the Arctic Sea Ice Blog, feel free to keep doing that. You can even go a bit off-topic every now and again. But if you want your thoughts to be more on target and easier to track, make use of the forum.

With a bit of luck I think the Arctic Sea Ice Forum can become an even better resource than the blog already is. I will update the Arctic Sea Ice Graphs page in the month to come, which will essentially make us ready for the 2013 melting season.

In name of the blog, the forum and the daily graphs, amen.

CryoSat-2 reveals major Arctic sea-ice loss

We knew that observations by the CryoSat-2 satellite were by and large confirming the modeled data from the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center, because of the recent publication in GRL of Laxon et al.'s CryoSat-2 estimates of Arctic sea ice thickness and volume,
but now it's official.

Here's the press release from the National Environment Research Council:

CryoSat-2 mission reveals major Arctic sea-ice loss

Arctic sea ice volume has declined by 36 per cent in the autumn and 9 per cent in the winter between 2003 and 2012, a UK-led team of scientists has discovered.

Researchers used new data from the European Space Agency's CryoSat-2 satellite spanning 2010 to 2012, and data from NASA's ICESat satellite from 2003 to 2008 to estimate the volume of sea ice in the Arctic.

They found that from 2003 to 2008, autumn volumes of ice averaged 11,900 km3. But from 2010 to 2012, the average volume had dropped to 7,600 km3 - a decline of 4,300 km3. The average ice volume in the winter from 2003 to 2008 was 16,300 km3, dropping to 14,800 km3 between 2010 and 2012 - a difference of 1,500 km3.

"The data reveals that thick sea ice has disappeared from a region to the north of Greenland, the Canadian Archipelago, and to the northeast of Svalbard," says Dr Katharine Giles, a NERC-funded research fellow at the Centre for Polar Observation & Modelling (CPOM) at UCL (University College London), who co-authored the report, published online in Geophysical Research Letters.

The findings confirm the continuing decline in Arctic sea-ice volume simulated by the Pan-Arctic Ice-Ocean Modelling & Assimilation System (PIOMAS), which estimates the volume of Arctic sea ice and had been checked using earlier submarine, mooring, and satellite observations until 2008.

Other satellites have already shown drops in the area covered by Arctic sea ice as the climate has warmed. Indeed, sea-ice extent reached a record minimum in September 2012. But CryoSat-2, launched in April 2010, differs in that it lets scientists estimate the volume of sea ice - a much more accurate indicator of the changes taking place in the Arctic.

"While two years of CryoSat-2 data aren't indicative of a long-term change, the lower ice thickness and volume in February and March 2012, compared with same period in 2011, may have contributed to the record minimum ice extent during the 2012 autumn," says Professor Christian Haas of York University, Canada Research Chair for Arctic Sea Ice Geophysics, co-author of the study and coordinator of the international CryoSat sea ice validation activities.

Read the rest of the press release here. The European Space Agency also has one which includes a video that visualizes the CryoSat-2 results:

Well, I'll be damned, it looks like someone notified the BBC before me! Jonathan Amos writes:

PIOMAS February 2013

Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center:

The good news is that the 2013 trend line is showing an uptick. The difference with 2012 and 2011 is now 751 km3 and 722 km3 respectively, which is much better than the 1000 km3 at the start of the year. Given the fact that I take PIOMAS very seriously since the previous melting season, I hope that the trend line gets closer to the ones just above it before the melting season starts.

Here is Wipneus' version with the calculated "expected" 2013 values (dotted lines), based on the same date values of 1979-2011 and an exponential trend.
A caveat from Wipneus: "Note that the statistical error bars are quite large."

CT SIA anomaly above zero

After all those negative records that were reported not so long ago (how many were there? I've lost count), it is nice to be once again given the opportunity to make known a positive record: Global sea ice area as reported on the Cryosphere Today website has been above the zero baseline for two days now (data here).

Even though the CT SIA anomaly dips ever lower, the anomaly can still go positive around this time of the year.  This event follows the previous one a lot earlier than the one before that, which was a record 444 days and the first full calendar year of negative anomaly.

As usual the Antarctic sea ice anomaly is so positive that it compensates for the semi-permanent negative anomaly in the Arctic:

Open Thread February 2013

The previous open thread has gotten full enough, so here's a new one.
We might want to kick off with this animation made by commenter A-Team:

His comment:

Don't miss this -- it's happening right now, by the hour -- so head on over to 80N 150W. A huge fracture has been opening a bit east of Barrow, Alaska the last few days and it's really accelerating. The AVHRR images come up every few hours as the satellite comes over -- but they're not archived so you have to "be there" to catch them. I attached a still of the key region with a few land features labelled and an approximate distance scale as the animations is intended primarily to illustrate pack ice motion.

The imagery motions agree quite well with the Navy HYCOM ice speed and drift animation. That predicts five days out and so gives some indication of what to expect. I just attached a still for today. All the ice is moving the same way, clockwise in the Beaufort Gyre. It is just that the ice southeast of the lead just can't keep up. The ice no longer has the mechanical strength that it once did and so is fracturing under extensional tension.

Thanks for keeping an eye on this, A-Team!