Friday, May 14, 2010

Comment on “Influence of the Southern Oscillation on tropospheric temperature” by J. D. McLean, C. R. de Freitas, and R. M. Carter

Well, it's not really news, but since the energiser bunny was boasting about his comment recently, here is ours, newly published for real:

Comment on “Influence of the Southern Oscillation on tropospheric temperature” by J. D. McLean, C. R. de Freitas, and R. M. Carter

And to save you from the effort of clicking the link, here's the abstract:
McLean et al. (2009) (henceforth MFC09) claim that the El NiƱo–Southern Oscillation (ENSO), as represented by the Southern Oscillation Index (SOI), accounts for as much as 72% of the global tropospheric temperature anomaly and an even higher 81% of this anomaly in the tropics. They conclude that the SOI is a “dominant and consistent influence on mean global temperatures,” “and perhaps recent trends in global temperatures.” However, their analysis is inappropriate in a number of ways and overstates the influence of ENSO on the climate system. This comment first briefly reviews what is understood about the influence of ENSO on global temperatures and then shows that the analysis of MFC09 greatly overestimates the correlation between temperature anomalies and the SOI by inflating the power in the 2–6 year time window while filtering out variability on longer and shorter time scales. The suggestion in their conclusions that ENSO may be a major contributor to recent trends in global temperature is not supported by their analysis or any physical theory presented in their paper, especially as the analysis method itself eliminates the influence of trends on the purported correlations.
Unlike Eli, our comment was so devastating that the original authors were unable to come up with a coherent reply. Oh, ok, that's not so different from Eli's case then!

9 comments:

EliRabett said...

Yeah, but you guys are pros, us bunnies are meerly auditors

Marco said...

And McLean et al was actually published in something that could be considered a reasonable journal.

McLean's reply was actually more coherent than that of Gerlich & Tscheuschner. The latter's response is a disgrace to any scientist. In my not so humble opinion, that is.

Martin said...

I may be missing something, but isn't Grant F as much an amateur in climatology as is the bunny, and the bunny has a framed diploma on his wall saying physicist? What G&T pretended to be doing was physics.

James Annan said...

Marco,

Yes, I agree that McLean - both original and reply - was a cut above G&T's stuff which is just crazy nonsense. In both cases, the comments are excellent, of course :-)

Marco said...

Don't tell the rabett, but yours is more coherent. Then again, you had an easier target. How do you react to utter lunacy?

And the reply is even worse than the original ("oooh, you have some tiny irrelevant chemists as co-authors; WE are theoretical physicists! HAIL US!").

deepclimate.org said...

That leaves just Klotzbach et al still standing in the collection of worst papers of 2009.

Is there a comment in the works for that one? If there is, I hope it also addresses the corrigendum, which is based on ocean and land tropospheric amplification factors that are physically incompatible with the original global factor used.

James Annan said...

TBH I would expect there are plenty of other papers just as wrong, but they don't get the fanfares :-)

I don't know of any comment in the works, but that doesn't mean there isn't one. However the corrigendum has taken some of the sting out of the most direct criticisms. Also, the real howler at the bottom of the pile is Pielke and Matsui 2005 which is out of time for comments. Of course by far the most common treatment of such bad papers is just to ignore them...which is exactly what has happened with PM05, outside the sceptic community.

Anonymous said...

Could you verify for a layman - I was under the impression that ENSO correlates fairly well to interannual global temps (not to long-term climate change). Does your paper challenge the short-term correspondence, too?

Barry.

James Annan said...

No, our comment doesn't challenge the short-term relationship (with a several month lag), in fact we mention that it has been known about for a long time.