Scientific Robustness Of The University Of Alabama At Huntsville MSU Data
By Dr. Roger Pielke Sr.
As a result of the persistent, but incorrect (often derogatory) blog posts and media reports on the robustness of the University of Alabama MSU temperature data, I want to summarize the history of this data analysis below. John Christy and Roy Spencer lead this climate research program.
The ad hominem presentations on this subject include those from the weblog Skeptical Science who have sections titled
Christy Crocks and Spencer Slip Ups
If this weblog intends, as they write, to contribute to
Explaining climate change science & rebutting global warming misinformation
they certainly have failed in this effort, with respect to the outstanding research that Christy and Spencer have accomplished.
To summarize specifically the UAH MSU dataset, it has gone through about 9 revisions (A, B, C, D, 5.0, 5.1, 5.2, 5.3, 5.4 – some listed in CCSP 1.1.) Two of the revisions involved changes Jim Wentz of RSS spotted, but the other seven were ones John Chrsity and Roy Spencer discovered (i.e. major ones like the spurious warming due to a change in the sensor when the satellite went in and out of sunlight).
Such corrections are what happens in the normal course of science when you are the first to build the data set and discover issues as time goes on, especially when a satellite goes through a calibration shift. Their data are publicly available and their methods published in a diverse range of peer-reviewed journals.
A example of their reporting on a correction and acknowledging who found it (in this case Jim Wentz) is written in the article
Christy, J. R. and R. W. Spencer, 2005: Correcting Temperature Data Sets. 11 November 2005: 972. Science. DOI:10.1126/science.310.5750.972
Text from their article includes [highlight added]
“We agree with C. Mears and F. J. Wentz (“The effect of diurnal correction on satellite-derived lower tropospheric temperature,” 2 Sept., p. 1548; published online 11 Aug.) that our University of Alabama in Huntsville (UAH) method of calculating a diurnal correction to our lower tropospheric (LT) temperature data (v5.1) introduced a spurious component. We are grateful that they spotted the error and have made the necessary adjustments. The new UAH LT trend (v5.2, December 1978 to July 2005) is +0.123 K/decade, or +0.035 K/decade warmer than v5.1. This adjustment is within our previously published error margin of ± 0.05 K/decade.”
I also reported on an independent check on the robustness of the UAH MSU analyses in my post
where I reported
In order to further examine the robustness of the Christy and Spencer analyses, in 2006 I asked Professor Ben Herman, who is an internationally well-respect expert in atmospheric remote sensing, to examine the Christy and Spencer UAH MSU and the Wentz and Mears RSS MSU data analyses. He worked with a student to do this and completed the following study
Randall, R. M., and B. M. Herman (2007), Using Limited Time Period Trends as a Means to Determine Attribution of Discrepancies in Microwave Sounding Unit Derived Tropospheric Temperature Time Series, J. Geophys. Res., doi:10.1029/2007JD008864
which includes the finding that
“Comparison of MSU data with the reduced Radiosonde Atmospheric Temperature Products for Assessing Climate radiosonde data set indicates that RSS’s method (use of climate model) of determining diurnal effects is likely overestimating the correction in the LT channel. Diurnal correction signatures still exist in the RSS LT time series and are likely affecting the long-term trend with a warm bias.”
The plot of the lower tropospheric temperature analysis, as obtained from the MSU data, for the RSS and UAH groups are shown below. The degree of correspondence between them is another check on the value of both data sets in assessing long-term variations in the global averaged lower tropospheric temperatures.
The bottom line conclusion is that the statements made by Kevin Trenberth, John Abraham, and Peter Gleick in
Opinion: The damaging impact of Roy Spencer’s science
that
Unfortunately this is not the first time the science conducted by Roy Spencer and colleagues has been found lacking. Spencer, a University of Alabama, Huntsville, climatologist, and his colleagues have a history of making serious technical errors in their effort to cast doubt on the seriousness of climate change. Their errors date to the mid-1990s, when their satellite temperature record reportedly showed the lower atmosphere was cooling. As obvious and serious errors in that analysis were made public, Spencer and Christy were forced to revise their work several times and, not surprisingly, their findings agree better with those of other scientists around the world…
are grossly incorrect and a retraction and a correction by Trenberth, Abraham and Gleick is appropriate. Similarly, weblogs such as Skeptical Science, if they want to move the debate on the climate issues forward, need to move towards a more constructive approach.
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I’d like to add this from Dr. John Christy, from a comment he left on WUWT in this thread. – Anthony
Some clarifications are needed. The orbital decay effect was discovered by Wentz around 1997 which induced a spurious cooling effect on one of our microwave satellite products (lower troposphere) but not the others. However, most people forget that at the same time Roy and I discovered an “instrument body effect” in which the observed Earth-view temperature is affected by the temperature of the instrument itself, leading to spurious warming (Christy et al. 1998, 2000). This effect counteracted about 75 percent of the orbital decay cooling effect – so the net effect of the two together was almost a wash (a point rarely acknowledged.)
In 2005, Wentz and Mears discovered an error in the equation we used for the diurnal correction in one of our products (again, lower troposphere) which we quickly corrected and then published a “thank you” to Wentz and Mears in Science for their cleverness in spotting the error with an update on what the magnitude of the error was. Again, the magnitude of this error was small, being well within our previously published error estimates for the global trend. (Note that we were first to discover the diurnal drift problem back in the 1990s and initiated various corrections for it through the years.)
Roy and I were the first to build climate-type global temperature datasets from satellite microwave sensors, so we learned as we went – and were aided by others who read our papers and checked our methods. My latest papers continue to investigate error issues of our products and of the products of others.
The review of my one publication in Remote Sensing last year was done quite professionally and it was clear to me and my co-authors that the referees chosen to review the paper were specifically knowledgeable of the various satellite, radiosonde and statistical issues, leading to some substantial and useful revisions.
Kevin Trenberth was my MS and PhD graduate adviser at Univ. of Illinois.
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If there was a prize for cherry-picking, “Skeptical Science” would be Fruiterer of the Year.
It’s crucial to keep things in perspective. This is Skeptical Science (SS) as penned by John Cook. It is a site characterised by abuse of the moderators position and and a Taliban intolerance of any deviation from fundamentalist climate change orthodoxy. Ignore them. Although there are one or two brave posters on that site ( the mirror image of R.Gates) the majority are not interested in scientific debate, only in trashing any opinion which regardless of accuracy, right or wrong, good or bad, they feel is heretical. And this post is from a self confessed luke warmist.
Well I can’t read the scale on the first graph (time) but I’m guessing, that the big sore thumb peak near the middle was around 1998.
So here is where I disagree with the myth of a “linear” long term trend of 0.142 deg C per decade. I for one refuse to use Kelvins for Temperature differentials.
But that graph actually shows no meaningful trend at all since around 1995, and to imply otherwise, is simply to imply something that isn’t true.
The graph clearly shows shorter periods of substantially faster warming, followed by even faster retrenchments; and no movement since 1995 or so.
The second RSS graph seems to clearly demonstrate a significant change near the middle from a not so blah earlier record, to a very blah recent record.
And who knows what is the correct time delay to allow between some meaningful causal change, and some apparent step Temperature change. I say apparent, because I’m not at all a believer that the purported global lower tropospheric Temperature “data” is at all continuous.
Seems to me, that it was about Jan 2001, when Christy et al, reported the simultaneous oceanic buoy air and surface water Temperatures, and showed that they were not the same, and also are not correlated. The actual air Temperature increase, was considerably less than the water Temperature over the 20 or so years they reported on.
And I don’t believe the sampling methodology complies with the Nyquist criterion, either spatially, or even Temporally, and in both cases, the undersampling is big enough to render even the average value unrecoverable.
But of course the current paper donnybrook is about other issues than pure science, and science paper peer review, and I am glad RP Snr is weighing in on this.
Dr Pielke writes:
If this weblog intends, as they write, to contribute to
“Explaining climate change science & rebutting global warming misinformation”
they certainly have failed in this effort, with respect to the outstanding research that Christy and Spencer have accomplished.
====================================
Well, Dr Pielke, you must be confusing ‘sceptical science’ with a site that actually cares about the truth regarding climate science, rather than say – erm, I dunno – a global warming propaganda site?
I have a couple of questions for Dr Pielke Sr.:
You refer to the claims on skeptical science as being ad hominem. I was wondering if you could clarify what you mean by that? I went to that section on skeptical science. And, it consisted only on referenced claims they made next to linked rebuttals. Perhaps the rebuttals are incorrect, but it seems a stretch to call the arguments ad hominem, since they focus on specific claims made by spencer and christy, not on their characters as people.
I agree with your point that your quote from the Trenberth, Abraham, Gleick article is unfairly harsh and personal. I also that revisions such as those made to UAH data set are part of normal science. However, that article is from “The Daily Climate”, not “Skeptical Science”. Could you please point me to an analogous statement on “Skeptical Science”?
Anyway, I’m not trying to be argumentative here. I generally think that the tone of skepticalscience is generally pretty good and stays clear from ad hominem’s or claims of conspiracy, but I am genuinely interested to hear why you feel otherwise.
Some data are more robust then others. This graph shows an unusual configuration within one of the top five temperature data sets used by the climate scientists in their calculations, predictions and computer models. I wander do they know of this little curiosity and if they do, what they make of it.
http://www.vukcevic.talktalk.net/Data.htm
Re: “Christy Crocks and Spencer Slip Ups”
“Slip Ups” seems innocuous. But I agree “Crocks” is offensive. I wrote Sk Sc about this. However, these are mild compared to the name calling that goes on here in the comments!
Me thinks that there is a whiff of double standards.
Can someone remind me how many times the temperatyre record for the 1930s has been revised/adjusted/’corrrected;
I agree with Gareth Phillips……. forget Cook. And, forget tweedle dee, tweedle dumb, and tweedle dumber. If they had an ounce of integrity, they’d never wrote that opinion piece, that contained zero science, which was nothing more than personal attacks in the first place. They don’t have any integrity and they’ve displayed their lack of courage for all the world to see. At least Dessler tried to address the science those 3 idiots didn’t even have the ability to do that!
Matt – The headers to their sections on John Christy and Roy Spencer
Christy Crocks and Spencer Slip Ups
are quite clearly (and unnecessarily) ad hominem, particularly the first one as Mike also replies in the comments.
Matt says:
September 12, 2011 at 12:09 pm
Anyway, I’m not trying to be argumentative here. I generally think that the tone of skepticalscience is generally pretty good and stays clear from ad hominem’s or claims of conspiracy, but I am genuinely interested to hear why you feel otherwise.
Garethman says,
Well Matt, we must have read different discussion zones. Ad hominem attacks are a real characteristic of SS with John Cook frequently using his role as moderator to insult posters safe in the knowledge he can delete any response. A casual flick through the site will show numerous examples of ad hominem attacks on posters he who’s view he does not like. I’d be happy to link you to a selection of classics but do not wish inflate the sites views by my own actions. If I, as a long term blogger, believer in climate change and used to the rough and tumble of debate, think SS is a dysfunctional site, trust me, thats a pretty bad indication.
I have tried to debate with cook via twitter after he attacked me for a tweet I made. He went quiet when I tried to discuss ENSO.
@ur momisugly.Vukcevic: Your charts are interesting but difficult to understand due to a lack of labels, e.g. what is shown on the y-axis? What is the significance of the red sign wave?
I get the feeling that Dr. Roger Pielke Sr. is an honest and objective ‘true scientist’ in the sense that whatever his research shows, he will report.
He (and Dr. Judith Curry) are a few luke-warmer climate scientists that I trust…
So then, I gather the lesson to be learned is that every time Kevin Trenberth publishes something someone doesn’t like, it should be immediately dismissed publicly with a reminder that no one should take seriously the future work of anyone who participated in a self-described “travesty”.
“Roy and I were the first to build climate-type global temperature datasets from satellite microwave sensors,…”
It seems easy to forget that we are talking about pioneers here. Others should be gratefull for these achievements.
Christy and Spencer have done great pioneering scientific work to produce the MSU dataset.
Remote sensing has been a triumph of modern empiricism.
I have nothing but contempt for fools like John Cook and his moderators who censor comments and cast slurs at truly sceptical scientists.
Trenberth has done good science in the past, but now seems to be losing his way. One day he will realise how he fooled himself but not many others. Too far up his own theory.
Wow, that’s absolutely awful and sick that Trenberth would ad-hominem one of his former graduate students.
I’m glad that Dr. Pielke made this post, as I am really utterly sick and tired of John Cook and Skeptical Science’s arrogance, and it needs to come to an end. Thank you Dr. Pielke for exposing them for who they really are.
If we followed the “Skeptical Science” method we would still be using maps from the middle ages to navigate our ships. Nice to see Dr Pielke point out the obvious. In the end the good science will stand.
—————–
Gareth Phillips,
I am very sympathetic to the gentlemanly discourse shown by R. Spencer and J. Christy. I appreciate Pielke Sr’s supportive post.
Thanks for your insight about the Skeptical Science blog site. I only go there if there is a reputable reference from an open commenter at a more open blog site. Which next to never, and that’s a long, long time.
You suggest there is at least one commenter at Skeptical Science who might be “the mirror image of R.Gates”?
The possible existence at Skeptical Science of an anti-doppelgänger to WUWT’s own R.Gates has deep metaphysical significance to the blogosphere.
R. Gates, are you OK with this idea of anti-cloning?
John
What bothers me about SS is the self-congratulatory nature of weak and often incorrectly supported declarations of the rightness of their AGW cause. Like RC, the links provided are (far too) often to papers that are themselves Dessler-style shoot-from-the-lip rebuttals of something so solid and contrarian that it gave the Team the willies. If you (laboriously) check the initial and follow-up articles, like the ones forthcoming in this S&B case, you will find that the positions mooted by Cook are often unsound and inflated. The exercise of the moderators cleaver obviously inhibits proper discourse.
They are counting on you not doing the work of actually understanding the issues and filtering out the ordinary stream of opinions from individual scientists. Mike, are you listening? It means work to understand! You gotta read all the papers, not listen to the opinions of a couple guys who read the abstracts.
Someone on RC even made a robotic responder that replies to questions with cut and paste links to papers that, if fully investigated, expose the weakness of the case to claim there is any detectable human imprint on the climate at all. Then he hooted about it and how easy it was to fool ‘skeptics’. They are counting on people getting sucked into a ‘party position’ and settling into a comfy AGW pew to admire the climate clerics pontificating on the terrifying tenets of da debbil CO2. Ignorance is not a virtue, no matter how comfortable it may make one among friendly leaders.
Misrepresentation of another guy’s paper is inevitable from time to time. We can deal with that. Serial misrepresentation is suspicious. It is not how progress is made!
Sceptical Science was once a good site, but John Cook has been rather naive in letting certain elements take control of the moderation process and thus set the agenda.
Most of the entrenched regular contributors fancy themselves as more knowledgeable experts as they attempt to demolish the papers of those truly qualified scientists that represent and present an alternate position to their own.
It is almost comic that all that they achieve is confirmation of the degree that the Dunning–Kruger effect is entrenched amongst those regulars.
The abuse of moderation process means that any posters who are able to present logical and coherent arguments that are unable to be countered or even addressed, gradually withdraw leaving the good old boys talking to and patting each other on the backs for being so clever.
Gareth;
I was four-square with you, till you used “who’s” instead of “whose”. Where are your intellectual standards, sir?
😉
;p
geo says:
September 12, 2011 at 2:41 pm
When you choose a most public venue to declare your personal war against science, you draw attention to yourself. He did this when he announced that CAGW should become the default hypothesis and that others should have to prove that there is no global warming. This put him in the same tiny ballpark as Al Gore. At any time, Trenberth could remove himself from that ballpark by withdrawing his statement. Because the statement amounts to a curse on science and because the statement has not been withdrawn, when someone calls him Travesty Trenberth they are simply reporting relevant important facts about his views of science. So, it is not an ad hominem. If you call yourself a pig then I am totally justified in calling you a pig.
I looked through SkepSci’s characterizations of Spencer and Cristy, they took some specific quotes from them and their rebuttals were mostly along the lines of “everyone else says they’re wrong”; here a new idea, point us at some peer reviewed papers, preferably some not hiding behind a pay-wall.. Maybe what we really need is something like arXiv for climatology, when we get stuck with a report of a report of a report, nothing beats consulting the original sources. One of the reasons Dr. Spencer gets my respect is because he not only reports results without regard to whether they support any position or not, but he can explain technical nuances so that even a layman like my self can understand what he’s talking about and I can decide the merits of his arguments on my own.