Recently on Judith Curry's blog, a guest post was submitted by DocMartyn which was a rather nicely (from a math perspective) done extrapolation of past tropospheric temperature trends and cycles out to 2040 and beyond. It was essentially a nice job of, as he put it, "graphology", or in other words "curve fitting". Not great science, but some nifty math. Essentially DocMartyn's curve fitting graphology approach has led him to conclude that tropospheric temperatures will remain flat to 2040 or so before accelerating upward once more.
I happen to strongly feel that DocMartyn's projective curve fitting approach will prove to be grossly in error (as almost all such curve fitting is, except for pure chance), but here's the thing-- in the big picture of Earth's energy imbalance caused by accumulating anthropogenic greenhouse gas emissions, the tropospheric temperatures are quite secondary. The troposphere is a low thermal inertia part of the overall energy system of the planet and contains only a fraction of the overall energy. It seems however, that there is an undue preoccupation with focusing on this part of the system-- probably because we as humans happen to live in it, and also because it is easy to measure. And since the troposphere can be fickle and far more subject to short-term noise from natural variability, it makes the most sense to look at the parts of the system such as the oceans and cryosphere that have greater thermal inertia and are hardest to change from short-term noise. When doing this, and comparing it to the constant upward trend in CO2 emissions, the following four charts become the most salient in terms of understanding what is really happening:
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:
According to the model data 2013 has peaked at a total volume of 21,823 km3 on April 17th, which is 100 km3 below last year's record. Since then, 2013 volume has dipped quite a bit below last year's number (295 km3 to be precise), but is still close to 2011 which has only 63 km3 more at this moment.
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."
The melting season is about to shift one gear higher, and so I thought it'd be useful to have a comprehensive look at this past winter (just like we did last year). As we saw in this recent PIOMAS update, it seems that this year's conditions for ice formation were better over on the Siberian side of the Arctic.
The Beaufort Sea had relatively little multi-year ice flowing in which should make the pack weaker there, as evidenced by the large cracking event of February and March. The image on the top right shows a map of the ice pack, where this year's thickness is compared to last year's (red = thicker, blue = thinner).
I want to look further into this by comparing the 2012/2013 winter with those of previous record years, such as 2006/2007, 2010/2011 and 2011/2012. Click on the images if you want a larger version.
The Polar Science Center has released some extra PIOMAS gridded data that allows smart bunnies like Wipneus and Chris Reynolds to show how ice thickness is distributed around the Arctic. Here's a thickness distribution map made by Wipneus that shows the difference between March 2012 and March this year:
It seems the situation has basically flip-flopped, with thicker ice now off the Siberian coast and thinner ice in the Beaufort and Chukchi Seas. This is most probably due to those big highs that caused a very strong Beaufort Gyre that pulled at the ice pack so hard it cracked all over the Beaufort Sea and beyond, but at the same time made the ice compact against the Siberian coast. This thicker ice along the Siberian coast is at a relatively low latitude and is bound to melt away anyhow, although it will be interesting to see when the Northern Sea Route opens this year.
Last year I was expecting thicker ice in the Beaufort and Chukchi Seas to protect the centre of the ice pack like had happened in 2010 and 2011, but I was completely wrong on that. The ice just disappeared at a rapid pace, an amazing sight. If the above map is correct we don't even have thick ice there now, and so I'm with Chris Reynolds when he says: "I expect an aggressive melt from the first week of June onwards, when the melt really starts within the Arctic Ocean."
Speaking of which: Chris has produced this thickness distribution map for March 2013, with next to that a table that shows the division between ice that is thinner than 2 metres and ice that is thicker than 2 metres since 1978:
According to the PIOMAS model there's even less thick ice than in the previous two years, which makes sense, of course, after last year's record smasher. There's now more first-year ice than there has ever been since the record started. Some real weird weather is needed to prevent this coming melting season from becoming a serious pretender to the throne.
To top this update off I present to you Andy Lee Robinson's latest PIOMAS vid:
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 from last month stands unwavered. The 2013 trend line has stuck to those of 2011 and 2012, and all three are now practically equal. There is 53 km3 less volume than last year, but 44 km3 more volume than in 2011.
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."
This is a guest blog I wrote for Climate Progress and Skeptical Science. You may use it as a new open thread to discuss the cracking event. I will try and do a more detailed winter analysis in April, if Allah and time permit.
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The sea ice cap on top of the Arctic Ocean is often imagined to be a monolithic, continuous sheet of ice floating on water. A closer look quickly shows it is rather a collection of larger and smaller pieces of sea ice. Of course, we have all seen the images of ice floes separated by open water during summer, but even during winter the ice pack gets fractured, leading to leads that quickly freeze over again. This explains how from the 1950's onwards submarines were able to emerge at the North Pole (the image on top is showing the USS Connecticut as it surfaces in the Arctic Circle on March
19th 2011; copyright: Kevin S. O'Brien, U.S. Navy). The subs couldn't break through the thick ice and had to look for a lead where the ice was thinner.
Strangely enough those who deny the reality and potential consequences of AGW still like to abuse this event and claim it somehow proves that nothing unusual is happening up North. It doesn't prove or disprove anything, as cracks and leads have always been a normal feature of the Arctic sea ice pack. But 'normal' is a word that has become less and less applicable to the Arctic in recent times. The 2012 melting season was the latest climax in a series of record years, that showed conclusively that the ice is thinner than it has been for a very long time.
We don't even have to await the coming melting season to see this re-confirmed. We can see it right now, at the end of the freezing season. Like I just said, cracks are a regular feature of the Arctic, but this video below, made by NOAA's Visualization Lab, shows a cracking event that is very rare, if not unique:
Ice, however thin, doesn't fracture by itself. It needs wind to pull the ice pack apart. This wind was provided by a big, intense and stubborn high pressure area that started about a month ago and kicked the Beaufort Gyre into action, which is an ocean circulation pattern that transports the ice in a clockwise fashion from the North American coast towards Siberia.
This short animation of ASCAT radar images shows the movement in 10 day intervals from January 1st onwards, compared to the previous three winters. The black dot represents the North Pole, the white mass below it is the northern part of the Greenland Ice Sheet, the brighter colours represent thicker multi-year ice that survived last year's melting season:
The previous pun - cracks of dawn - was wearing off, and the comment section was getting full, so here's a new pun and blog post dedicated to the cracking event that started in the Chukchi and Beaufort Seas a couple of weeks ago, and then moved on to the multi-year ice against the Canadian Archipelago. This is also discussed in the Arctic Sea Ice Forum (ignore the security warning and make an exception as https is actually safer than http).
This image was posted yesterday by Chris Reynolds from the Dosbat blog:
To recapitulate: It is normal for the ice to crack and for leads to occur. However, this is very extensive cracking and there are some very big leads, and all of it seems to come earlier than expected. Given last year's melting mayhem and the low amount of multi-year ice, it makes one wonder whether this early cracking will have any effect in the melting season to come.
There are still several weeks to go before this part of the Arctic is going to start melting, up till then the ice will actually thicken some more, even when the Sun's rays start to reach the ice. But the ice is already getting broken up in smaller pieces, which means that 1) the pack becomes more mobile (like we saw last year), and 2) the thin ice that now grows to fill up the leads, will go first when the melting starts, potentially leading to more open water between floes to absorb solar energy and convert it to heat.
But maybe not. Maybe this will have zero influence. We don't know. That's why we watch.
PS A-Team did some more of his magic and produced this image showing the temperature of the ice and the cracks between floes (click for a larger version):
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:
Excellent news! The trend line has crept up some more and 2013 now has 133 km3 more ice than 2012 and is virtually tied with 2011. It seems the cold of the past weeks has thickened the ice pack considerably. I was getting worried about the coming melting season, especially with those huge cracks already opening up, so this is definitely a relief.
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."
I was hesitating whether I should write about this (besides my personal combination of busy/lazy) for a couple of days, because the Arctic is such an amazing place that it's easy to get carried away. When you see something for the first time, it's tempting to go: "Oh my Gawd, that haz got to be the first time!" That happens to me a lot, especially during winter. It's only logical as we are seeing a lot of things for the first time, or for the first time since a very long time. But there still remains a very fine line between 'unique' and 'unusual, but not unique'. A line that can sometimes be difficult to tread.
For instance last year at the start of February I wrote about the spectacular lack of ice in the Kara and Barentsz Seas, notably around Novaya Zemlya. I had a hunch that this was pretty much unprecedented during the satellite era and said as much in a guest post for Climate Progress. I was mildly criticized for it by the NSIDC's Walt Meier via Climate Central (and I will never forgive him for it ;-) ). Now the hunch turned out to be reasonably correct - although there had been a similar retreat of ice at a later date in 2011, caused by wind patterns - but I didn't invest the time to make sure it was.
This year things are calm in the Kara and Barentsz Seas. At the surface that is, with not even a breeze towards the coast to show how strong or weak the ice is. But as usual, when it's calm on one side of the Arctic, something is going on on the other side. Some commenters have been keeping a sharp eye on this, and I think it now merits a blog post of its own, if only because of the possible implications this event might have for the ice pack once the melting season gets underway. And it's big time spectacular.
Last week, on February 22nd commenter A-Team - who has really been animating the blog lately, figuratively and literally speaking - made the animation you see on top of the post, showing massive cracking in the Beaufort Sea. In the following days fellow commenter Jim Hunt picked up on that and wrote a blog post on his Econnexus blog called Arctic Sea Ice is Cracking Under the Strain with a spectacular image of the ice pack in the Beaufort Sea on February 27th.
Meanwhile over on the Arctic Sea Ice Forum commenter BornFromTheVoid remarked that a similar thing occured last year in April. A-Team was quick to turn that event into an animation (that I had to edit a bit to cut down on size):
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