Arctic Methane: What can AIRS tell us. Part 2.

This post won't really make much sense unless you've read the original post. It would also help to check out the videos of AIRS methane retrievals that I've previously posted.

Dr Yuragonov was good enough to point to some significant problems with a conclusion I drew in my previous post. In the meantime something else has occurred to me. So this post in essence is intended to add some major caveats to my claimed observations of apparent recurrent small scale anomalies in the AIRS images. The thrust of this will be towards the Laptev Sea anomaly because of it's possible linkage to Semiletov and Shakhova's work in that area. However these caveats also apply to the areas of the Lena River and the Yukon.

Mid January Miscellanea.

Arctic Methane: What can AIRS tell us?

In the last few days I've posted a set of polar view videos of AIRS retrievals of methane. I've been seeing what I can discern from these, so here are a few observations based on them. This isn't the whole story, others might see details I've missed, or be able to correct me. As usual feel free to post comments, I'd also be interested in any links to discussions elsewhere.

Arctic Methane: AIRS videos.

NOTE - the source images for these videos have been changed with effect from October 2012. This means I will need to recompile and update all of the videos from scratch. I aim to do this by the end of the month but am unwell at present - so can't do right now.


There's been a flurry of activity on the 'net about methane and the Arctic recently. This seems to be related to the AGU poster by Semilitov & Shakhova and new research from them due for publication this year. The ever-excellent Realclimate have posted two articles by Dr David Archer, here and here. Neven's Sea-Ice blog (also excellent) addresses the issue here.

Cold Winters: The Arctic Connection.

The recent apparent abatement in the warming trend seen in some datasets (i.e. HAD/CRU & GHCN) though not in all (i.e. GISS) has been used to claim that global warming has ended. This misuse of the issue is a shame because there is actually an interesting question here, aside from the agenda-driven obfuscation. However as someone who often has to use Google to find sources on climate change, sorting the wheat from the chaff is an everyday activity.

So what has been going on? Two papers published in 2011 provide a broadly coherent picture. Kaufman et al examined the issue of temperature changes from 1998 to 2008. They found that emissions of sulphates aerosols (China's coal consumption playing a dominant role) offset most of the forcing from rising greenhouse gas emissions with dominance of La Nina ENSO phase and reduced insolation due to the solar cycle explain the lack of warming over that period. In contrast Foster and Rahmstorf consider the longer period 1979 to 2010 and find that over that whole period ENSO and volcanic forcing (stratospheric aerosols from Plinean eruptions) contribute the most with a lesser contribution from reduced solar insolation. Once these factors are allowed for Foster & Rahmstorf find that the signature of global warming is clear and unabated over that period. However both Kaufman et al and Foster & Rahmstorf consider the annual average temperature, there is new research that shows and explains a regional seasonal signal of devatiation from the pattern of global warming.

Cold Winters: The Snow Advance Index.

Recently (well, back in November) Dr Judah Cohen published a new paper on the linkage between Siberian snow cover and Northern Hemisphere winters. The paper By Judah Cohen and Justin Jones is "A new index for more accurate winter predictions." There's a link to it at the end of this post. I've previously commented on the possibility of increased incidence of cold winters due to low solar activity and Arctic sea-ice. I've seen those as biassing for colder winters, with Cohen's previous work on Siberian Snowfall showing a trigger for specific cold winter events. However Cohen and Jones' new index makes me wonder what room there is for the other factors.

AGU: Hansen, Rohling & Caldeira.

Last week there was a press conference with Jim Hansen, Eelco Rohling, & Ken Caldeira at the AGU. I'm a bit late on it, just got round to catching up on RC's coverage of it. But this is well worth watching, including the press questions at the end. Rather than use the Blogger video window - which is too small for this - here's a link to the Youtube page. The accompanying powerpoint presentation is available here.

Er.

That's it.