This is a thread to discuss issues related to the 2011 Arctic sea ice minimum. The following graphs will update every day:
JAXA Sea ice extent:
Cryosphere Today sea ice concentration:
How Soon is now?
Willie Soon is a name that pops up every so often in climate ‘debate’. He was the lead author on the Soon and Baliunas (2003) paper (the only paper that has ever led to the resignation of 6 editors in protest at the failure of peer-review that led to its publication). He was a recent speaker (from 37.20) at the 2011 Heartland Institute conference, and can be counted on to produce a contrarian take on any particular issue that anyone might care about – ranging from climate, to mercury in fish and polar bear population dynamics.
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Lu: from ‘interesting but incorrect’ to just wrong
Some readers might recall a story from a couple of years of ago relating polar ozone depletion to cosmic rays and the subsequent failure of predictions made using that theory. The idea came from from a Qian-B. Lu (U. Waterloo), and initially seemed interesting (at least to those of us who were not specialists). Perhaps cosmic ray induced chemistry was playing some part in releasing chlorine from CFCs as well as the more accepted idea of heterogeneous chemistry on polar stratospheric particles? Lu’s predictions for increased polar ozone loss in 2008/2009 as a function of the low solar activity (and therefore higher CR flux) did not come to pass. Worse (for this idea), new analyses demonstrated that the hypothesized CR-induced CFC loss wasn’t detectable at all.
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Under and over the ice
I really like the fact that there is still so much to discover about important parts of the climate system. The Bell et al paper in Science Express this week (final version in Science) reporting on the surprising results from airborne ground-penetrating radar studies of the Antarctic Ice Sheet is a great example. The ice sheets themselves are the biggest challenge for climate modelling since we don’t have direct evidence of the many of the key processes that occur at the ice sheet base (for obvious reasons), nor even of what the topography or conditions are at the base itself. And of course, the future fate of the ice sheets and how they will dynamically respond to climate warming is hugely important for projections of sea level rise and polar hydrology. The fact that ice sheets will respond to warming is not in doubt (note the 4-6 m sea level rise during the last interglacial), but the speed at which that might happen is highly uncertain, though the other story this week shows it is ongoing.
West Antarctica: still warming
The temperature reconstruction of O’Donnell et al. (2010) confirms that West Antarctica is warming — but underestimates the rate
Eric Steig
At the end of my post last month on the history of Antarctic science I noted that I had an initial, generally favorable opinion of the paper by O’Donnell et al. in the Journal of Climate. O’Donnell et al. is the peer-reviewed outcome of a series of blog posts started two years ago, mostly aimed at criticizing the 2009 paper in Nature, of which I was the lead author. As one would expect of a peer-reviewed paper, those obviously unsupportable claims found in the original blog posts are absent, and in my view O’Donnell et al. is a perfectly acceptable addition to the literature. O’Donnell et al. suggest several improvements to the methodology we used, most of which I agree with in principle. Unfortunately, their actual implementation by O’Donnell et al. leaves something to be desired, and yield a result that is in disagreement with independent evidence for the magnitude of warming, at least in West Antarctica.
In this post, I’ll summarize the key methodological changes suggested by O’Donnell et al., discuss how their results compare with our results, and the implications for our understanding of recent Antarctic climate change. I’ll then try to make sense of how O’Donnell et al. have apparently wound up with an erroneous result.
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