the Air Vent

Because the world needs another opinion

Dot Earth on O10

Posted by Jeff Id on December 30, 2010

Andy Revkin of Dot Earth has published a post on our Antarctic results among other things. Eric Steig has placed some far more detailed comments on our results on line with it.

2) The results appear to confirm all of the key results in our 2009 Nature paper, notably the significant warming in West Antarctica, with especially strong warming — very widespread and including all of West Antarctica and much of East Antarctica — in spring.

I do wonder what it means when a paper with half the calculated warming trend agrees with another but I’m just an engineer.  The column marked S09 below is Steig’s result for comparison to the two primary methods demonstrated in O10.  You can see the “all of West Antarctica” comment is interesting when the EW version came up with statistically insignificant trends.  RLS though is probably more correct but compared to S09’s very high trend of 0.2C/decade or 2C per century it’s quite a bit lower.   What it means though is that we can barely tell if any real warming happened at all vs the certainty of S09’s 0.2 +/- 0.09.

Region RLS  C/Dec E-W  C/Dec S09   C/Dec
Continent 0.06 ± 0.08 0.04 ± 0.06 0.12 ± 0.09
East Antarctica 0.03 ± 0.09 0.02 ± 0.07 0.10 ± 0.10
West Antarctica 0.10 ± 0.09 0.06 ± 0.07 0.20 ± 0.09
Peninsula 0.35 ± 0.11 0.32 ± 0.09 0.13 ± 0.05

Another issue which needs to be looked at is the seasonality of trends.  Ryan noted differences in the peninsula matching seasonal trends which again pointed to the blending of peninsula  information across the continent in S09.

Well, I think Ryan said it better anyway:

Certainly other portions of S09 are confirmed by our paper (such as overall positive trends).  However, we note that earlier studies also showed the same things, so these were not newly introduced with S09.  The results that were newly introduced with S09, on the other hand, are all shown to be artifacts.

There is another comment by Dr. Steig which I would like to discuss:

4) The only other major difference in the findings, compared with our paper, is that we show significant warming over the eastern Ross sea region, while O’Donnell et al. show cooling, particularly in winter. I’m very skeptical of this result, because it is distinctly at odds with other assessments of trends in that region.

Addressing this properly would require a little time with the offset calculations to separate and plot Winter trends, I may do that later but for today it is worthwhile to simply place the offset reconstructions next to the results.  The Ross region is in the southern portion of the graph attached. There is a bay like region which is covered with the Ross ice shelf year round.  Note the white coloration of the temperature stations immediately to the West of this bay.  This information is taken directly from temperature stations which have been offset such that averaging adjacent stations with trends don’t skew the results.  Basically, it’s as simple a method as possible for knitting temp anomaly together reasonably.  The actual data produces a nice red in Ross and nice White next door to the West.

Below is what the visually very similar O10 result looked like this for RLS:

Now this doesn’t address the Winter critique specifically but this shows that visually our methods spatially distribute the temperature station information with respect to the actual measured ground data.  There is nothing in the method which would allow an accurate trend distribution overall and an inaccurate one in Winter. However, I believe the area weighted version may actually be more accurate than the satellite information methods due to distortions created by Chladni patterns. Small areas of the analysis can become exaggerated or minimized in trend based on their fit to the resonant modes of PCA decomposed spatially autocorrelated data.  Basically, Steig may be partially correct but I’m skeptical of any large differences from the O10 and area weighted analysis.

Anyway, Nic had some particularly strong comments which are published in full at Dot Earth.

49 Responses to “Dot Earth on O10”

  1. Kan said

    “…when a paper with half the calculated warming trend agrees with another…”

    All anyone needs to know is that it is warming.

  2. Steve Fitzpatrick said

    Jeff,

    Do not despair. Talk of extreme warming is Antarctica is (at least for now) over. I do not think this is a subject Eric and company will have the stomach to return to any time soon. Your paper has shown that the Antarctic trend, while marginally positive, is insignificant outside the peninsular and nearby regions.

    That Eric insists on noting how your results confirm that the “risk” of warming to the pine island ice self is an embarrassment, and only confirms the discussion is essentially over. Forget about Antarctica melting linked to sea level rise for the foreseeable future.

    You have helped to reign in one small portion of the climate lunacies. Many thanks.

  3. Kenneth Fritsch said

    Jeff ID, your juxtaposition of the thread titled Botched Predictions of the Past and the link to the Steig comment on O10 in this thread on how O10 confirms S09 may have been accidental, but I must say it was appropriate.

    While it is always difficult for most people to admit a weakness in their methods and predictions, it would appear that the more one is into advocacy the more difficult even hinting at a problem is a problem. Notice that some of the most rash predictions in the Botched thread were said, after the fact, by the predictors to be incorrect only in timing. Who are these replies, such as that supplied by Steig, supposed to be addressed. Certainly thinking people can look at the evidence supplied by O10 and S09 and decide for themselves how different the results truly are. One can make any general comment that might seem cogent at the moment because they avoid addressing the specific differences, just like the failed predictors can generalize about their predictions coming true in some distant future.

    Steig’s comment about (a very brief and vague) reference to admission in the S09 paper about the Peninsula trends being understated is correct, but the rest of the paper would appear to be in conflict with that statement. I’ll provide an excerpt later here to show this. He waves off the problem by saying that we already have much data for the Peninsula. Would that predicament have been better handled by that intensely colored Nature map being covered with question marks in the Peninsula area? I also note Steig makes a hand wave to a Mann comment on the dangers of evidently doing what O10 did in using the satellite data for spatial reference and the surface stations for temporal reference – even when admitting the trends from the satellite data could be unrealistic. Steig also eludes to reanalysis results that I noted before is probably the next step in attempting to make use of the existing satellite and surface station data in methods different than used in O10.

    I see absolutely no reason to hold back on criticism of Steig after reading his remarks about Steve M.

    Andy Revkin’s comments were rather expected from a defender of the status quo on climate science. It should be noted that he was defending too far when he said that Steve M should not complain about the 88 page review reply required for a reviewer of O10 when as he opines Steve M’s blogs can be lengthy. That is about as silly as you can get in the defense game.

    By the way if Team members agree with Steig that O10 confirms the results in S09 why did they make the effort for the O10 authors to jump through hoops.

    Jeff, when the comments such as Steigs’s, attempting to minimize differences, are made on blogs just keep posting the summary of O10 and S09 as you have here on this thread. Thinking people will understand.

  4. Kenneth Fritsch said

    All anyone needs to know is that it is warming.

    That comment is profoundly what confuses the AGW discussions and forgets that the issue is indeed how much warming and the beneficial/detrimental consequences thereof.

  5. Kenneth Fritsch said

    In the excerpts below S09 appears to blithely accept the results they have calculated for the regions of the Antarctica, including the Peninsula.

    Our reconstructions show more significant temperature change in Antarctica (Fig. 2), and a different pattern for that change than reported in some previous reconstructions5,7 (Fig. 3). We find that West Antarctica warmed between 1957 and 2006 at a rate of 0.17 plus/minus 0.06 degree C per decade (95% confidence interval). Thus, the area of warming is much larger than the region of the Antarctic Peninsula. The peninsula warming averages 0.11plus/minus0.04 degree C per decade. We also find significant warming in East Antarctica at 0.10 plus/minus 0.07 degree C per decade (1957–2006). The continent-wide trend is 0.12 plus/minus 0.07 degree C per decade.

    However, it is noteworthy that both in the reconstruction and in the model results, the rate of warming is greater in continental West Antarctica, particularly in spring and winter, than either on the peninsula or in East Antarctica.

    Certainly the remark below is in major contravention with O10.

    An outstanding question in Antarctic climatology has been whether the strong warming of the peninsula has also occurred in continental West Antarctica19. Our results indicate that this is indeed the case, at least over the last 50 years.

    Finally we get, way late, in the paper the reference to a problem with cutting off the higher order terms in the PCA. It also appears that Steig does not discuss in his O10 reply the full rational for cutting off early the PCs and giving once again his rendition of the physical meaning of the 3 PCs selected.

    Principal component analysis of the weather station data produces results similar to those of the satellite data analysis, yielding three separable principal components. We therefore used the RegEM algorithm with a cut-off parameter k=3. A disadvantage of excluding higher-order terms (k3) is that this fails to fully capture the variance in the Antarctic Peninsula region. We accept this tradeoff because the Peninsula is already the best-observed region of the Antarctic.

    I think S09 is a valuable paper for those who are not climate scientists but want to read these papers and get a feel for where the authors are confident in their results and where one must follow up on wording that appears vague.

  6. Brian H said

    Steve F.;
    Edit note: that’s “rein in”. Horses, not kings. ;)

    I wonder now if Steig’s remaining career will be spent trying to re-cast and justify S09. It’s beginning to look that way.

  7. Kan said

    Kenneth,
    Indeed, profoundly confusing. That is why it is so artful whenever it is said that O10 confirms S09.

  8. Mark T said

    I don’t know why any of you ever defend Steig, he’s really a jerk and clearly intellectually dishonest.
    Mark

  9. Mark T said

    It’s not artful. Steig’s audience consists of people that understand the concept even less than he does himself (my impression is that Steig was thrown in as a new voice with ties to Antarctica as some sort of confirmation of his authority… I would not be surprised if it was all Mann.) It takes no art to convince those starving for confirmation of their belief system. He gets chewed up anywhere else such silly claims are made.

    I guess going down in history as the stooge that blindly followed Mann off the cliff will serve as sufficient punishment.

    Mark

  10. Geoff Sherrington said

    Dominantly westerly winds hit the long N-S tongue of the peninsula, rise over it and fall back to sea level again.

    A theoretical mathematical analysis would need to involve adiabatic cooling as the air rose over the peninsula, then warming as it fell. So a mathematical model could well have some dependence on assumptions about the vertical rate of change of air temperature measured close to ground, where transfer might happen.

    Depending on kinetics, one can imagine adiabatic effect with altitude in two ways, one without other forms of heat transfer (e.g. the isolated vertical column analogue) and another where there is heat transfer (as if, in the extreme, our theoretical vertical column nestled against a vertical cliff and conduction happened.)

    Is there any meat in this example that could go to explaining the peninsula heating? I note that further north, some animations of temperatures do another jump as they cross the Andes around 40 to 50 deg S.

    Is there a difference in peninsula heating derived from ground stations when compared with satellite lower atmosphere? One has to accept ab initio that westerlies crossing land here will transfer different heat quantities to/from land than to/from sea. Is the difference a significant part of the temperature record?

  11. [...] This post was mentioned on Twitter by Science Blog News, C Jenkins. C Jenkins said: Dot Earth on O10 http://goo.gl/fb/1Vi1c [...]

  12. AndyL said

    Steig keeps using the phrase “significant warming” which is apparently confirmed by O10.

    I suppose he means ‘statistically significant’ or even ‘small but statistically significant’ though to the lay reader it appears to mean something more dramatic.

  13. stan said

    Someone please correct me if I’m wrong, but it appears to me that a lot of skeptics are falling into the same hubris trap that ensares the team. I thought that Steig made two major mistakes. First, he screwed up stats techniques he poorly understood (which resulted in smearing temps all over the continent). Second, and far more important, he foolishly tried to make definitive statements about temperature trends with a really crappy bunch of data from a group of stations whose coverage was grossly inadequate.

    If my understanding is correct, why is anyone arguing with him about trends? If only a fool would try to massage a faint trend from grossly inadequate information, why bother? The first path to wisdom is to admit ignorance. If the information is inadequate in terms of quality and coverage, it’s inadequate.

    [To use a football analogy (American) -- this seems like people arguing over the play call when the coach chose to go for it on 4th and 30 from the shadow of his own goal rather than punt. Perhaps the post corner would have been better a better choice than a QB sneak, but isn't the real mistake the fact that he didn't punt?]

  14. You guys – O’Donnell, McIntyre, Lewis and Condon are being hung out to dry – as we speak.

    Whenever I read Mr Revkin, I have to admit, I feel waves of revulsion wash over.

    You had to fight obstructionism precisely due to abuse of the anonymous peer-review process and this dishonesty is being chalked up to “running the gauntlet” and “civil and reasoned discourse” and the publication of your paper itself is being chalked up to the “remarkable process called the scientific method, together with the relatively modern innovation called peer review”.

    What a paper is understood to be, and its role in the pantheon, is *not* determined primarily by its data or results – for the short- and the medium-term. It is determined by the scientific advocacy skills of its authors and proponents. It seems McIntyre is the only one who grasps this at the moment.

    Eric Steig has now called your paper an “imitation”. I am pretty sure, in short order, he will probably be able to claim that your paper does not even exist and his results are to be deemed primary.

  15. Are my comments being pre-moderated?

    REPLY: Nope, it’s all up to wordpress. I have little control over it. I think if another blog reports your posts as spam enough times it may add your email to a list but that is just a guess.

  16. Jeff Id said

    Stan,

    I’ve heard these kinds of comments many times and flatly disagree with them. There are statistical methods to determine whether a ‘trend’ is discernible in the data. Claiming that we don’t know automatically is as bad as claiming we do know automatically. Using reasonable statistical tools and thoughtful examination are the answers to this problem.

    For instance, we see statistically significant warming in the West Antarctic in RLS method and insignificant warming in the EW method but both are close to the 95% mark. If we treat the methods as equal, and we know of the potential for problems in the station measurements, what can we really say about the West region? Not much IMO. The warming trend could very much be over or understated by enough to change the result. However, when considering other information like the very significant peninsular warming it is likely that we have detected a true but relatively mild warming trend of some sort.

    The temp stations in the Antarctic are far better than those we find in the US, simply due to a reduction of UHI. I bet there is still plenty of UHI though at some locations but have no proof other than a couple of photos. The data isn’t perfectly clean and has problems but there are a number of stations which measured for the whole 1957 to present length of time. Using just those long record stations (no sat data) similar results are achieved for continental trend as when all the data is combined using offsets. Now I admit that if someone asks me what the temp trends are in the Antarctic, my favorite method is simply the closest station area weighted method. That’s because the spatial distortions which the more complicated regression methods create can cause problems with spurious information blending in small areas. The problems have been minimized though (basically to the limit of the data) in O10. What should settle most peoples mind is that there won’t be any big changes from our result in the future.

    When I read automatically negative comments on trends and what we know, it makes me think that people are wishing they don’t exist. The fact that there are problems in the data is not enough to make automatic conclusions about what we know from the data. In my experience, I know of no data which didn’t have problems.

    With all that said, the trick is to read the CI’s, grasp the problems in the data, and make your conclusions from that point. My own are, yes there was warming in these temp stations continent wide. However, the continental warming was not greater than the trends created by the noise so could be noise or UHI bias nobody knows. In all regions excepting the peninsula, detected warming was not much greater than the CI so when considering station quality, declaring a ‘known’ long term warming trend is problematic. Again, these are just my views. Steig obviously sees a barely significant warming from RW and an insignificant warming from EW in the West region differently than I. In the end though we must rely on our statistical tools and brains to make conclusions about the data rather than simply chuck the data to the wind based on personal feelings.

  17. Doug Proctor said

    Kan @1 said: All anyone needs to know is that it is warming

    The disappointing and scary lesson here is that the warmists do not understand that CAGW or AGW is dependent on the rate of warming, not actual warming. The warmist does not acknowledge that the warming from 1850 to 1940, and the cooling from 1940 to 1965, though recognized to be non-AGW, non-CO2, has an bearing on the post-1965 temperature rise. History has nothing to say about the present or the future, and a hypothesis of “catastrophic” global warming actually does not need the C-situation to be verified.

    It is as if Kan thinks the argument about how many angels can dance on the head of a pin were about whether they were wearing sneakers or work boots, not about whether they have a corporeal (or any) existence at all. With such reasoning (or lack thereof) in his camp, I cannot see an end to the CAGW/not-CAGW dispute. Perhaps one day the warmists will be more honest and just say, “The subject is not up for discussion!” and then send us to our room like grumpy Dad did.

  18. Kenneth Fritsch said

    Eric Steig has now called your paper an “imitation”. I am pretty sure, in short order, he will probably be able to claim that your paper does not even exist and his results are to be deemed primary.

    I would think by now that it is clear that what some Team members claim (in very general terms in order to avoid the obvious conflicts) for a paper is for advocacy purposes and can be ignored in favor of looking at the details and specifics of the paper(s) in terms of scientific evidence. You are giving some of these advocate/scientists too much credit for credence when they are in advocacy mode. Would you take seriously the partisan rationalizing of a politician? Jeff Id is doing right by merely posting the trends from S09 and O10. The devil is also in the details and can be appreciated by reading carefully both of these papers.

    The compliment from Steig about the amount of sensitivity testing that was in O10 is a very important point – as, in my view, it separates O10 from the too frequent lack of such testing we see in too many climate science publications.

    You guys – O’Donnell, McIntyre, Lewis and Condon are being hung out to dry – as we speak.

    Eric Steig has now called your paper an “imitation”. I am pretty sure, in short order, he will probably be able to claim that your paper does not even exist and his results are to be deemed primary.

    I think you should say that these actions are merely attempts and that in the process we learn a little more about those attempting. No need for a war of words when we have published evidence in S09 and O10.

  19. dearieme said

    “You have helped to reign in one small portion..”: arise, King Jeff.

  20. That Eric insists on noting how your results confirm that the “risk” of warming to the pine island ice self is an embarrassment, and only confirms the discussion is essentially over. Forget about Antarctica melting linked to sea level rise for the foreseeable future.

    This should be in a press release and interview.

  21. Layman Lurker said

    Eric seems rather desparate right now. The only defense of his paper that is open to him is to suggest that the part of S09 that really “mattered” was the finding of warming in the PIG area which conincides with O10. The only problem is that his paper has been shown to severly bias the 50 year trend and then mangle the distribution of this biased trend through time and space. Yet somehow, this method which got 95% of Antarctia demonstrably wrong and biased, has produced a trusted result in Ellsworth Land?

    The warming of West Antartcica is demonstrably wrong and an artifact of a badly flawed method – plain and simple. The findings of S09 in Ellsworth Land are not independent of his demonstrably mistaken findings for the rest West Antarctica. On the contrary, Ellsworth Land lies within this artifact. IOW it is part of the same mistake. Any connection of this area with O10 or reality is purely conincidental.

  22. ThomasJ said

    How about getting back to basics? There is nothing like ‘global temperature’, there are no revelance at all to ‘trends’, there are major flaws in all the so called ‘computer models’ (as always, irl!).
    Query is, however, how to get back to the basics?
    Here, in Europe/Sweden, we’re more than less forced into the Barossol’s con and we – ‘the small people’ cannot do a single simple thing about it…

    My part of the World hurts/pains me!

    Brgds from Sweden and Ett Gott Nytt År!

    //TJ

  23. Pat Frank said

    #16 “There are statistical methods to determine whether a ‘trend’ is discernible in the data.” This belief, overwhelmingly dominant in modern climate science, is the source of almost all of the problems with the field.

    Statistics deals only with numbers. Physics deals with causes. Statistics can describe the characteristics of the strings of numbers known as ‘time series’ in climatology. Statistics can also determine whether there is a “trend” in that string. But statistics cannot determine whether the trend has any physical meaning. Nor does any given statistical result automatically garner physical meaning, when that result ‘seems reasonable.’

    Physical meaning involves not just causality, but also whether the numbers themselves have any meaning. The values of observed magnitudes are just numbers. One can examine them using any statistics one likes, and the results will remain physically meaningless unless the results are embedded within physical theory.

    In terms of magnitudes, surface temperature measurements gain their primary physical meaning from Thermodynamics and their secondary meaning from the physical theory of instrumentation. Thermodynamics tells us what we’re measuring, and instrumental theory tells us about the accuracy and precision of the observations. In the case of surface air temperatures, instrumental theory along with empirical testing tells us that the magnitudes of the observations are good to maybe (+/-)0.5 C, and that’s systematic error, not random error, and under very good conditions.

    Nevertheless, regardless of accuracy or precision, one can always record a number to three significant figures and can always get strings of temperature numbers that are amenable to statistical processing. The strings can show correlations and can exhibit trends. One can even express the statistical results to hundredths or thousandths of a degree.

    But from the physical (+/-)0.5 C point of view, correlations and trends less than at least 0.5 C are meaningless.

    Apart from the poor thermal representation of the Antarctic provided by 29 irregularly scattered stations, the field accuracy of the instrumentation at the Antarctic stations themselves is entirely unknown. The climate scientists who have given us these Antarctic trends pay no apparent attention to basic data quality, accepting the temperature numbers as canonical to hundredths of a degree.

    The argument between O10 and S09 is about a very sophisticated statistical methodology. It’s clear that Jeff, Ryan, Steve, and Nic have won that argument. But the whole argument about whether Antarctica has warmed by 0.1 degree per decade, or less, or more, or where, is little more than climate theology, with temperature numbers cast as the cherubs and the trends their choreography — equivalent to dancing on the heads of pins.

  24. kim said

    Andy’s starting to stretch a little for his defenses of the alarmists. Careful, Andy. Hey, go read Feynman. Or Dot Earth ’08.
    =============

  25. Layman Lurker said

    Interesting comment from Tom Crowley at Dot Earth about the suggestion of possible obstructionism in the peer review procsess at JoC.

  26. stan said

    Jeff,

    I cannot tell what the “avg temperature” of the USA is (even if I were to have data of perfect accuracy) from sites at only 3 or 4 locations and a bunch in Florida or California. In fact, from what we do know about California, small changes in the exact location of certain thermometers would make an enormous difference in the temperature of that one state alone.

    In Antarctica, the interior coverage is way too sparse and the trends being coaxed from the data are simply too fine. The world’s greatest stats geek can slice and dice, coax and massage, shake and bake to his heart’s content — he just doesn’t have enough coverage of the continent to say anything that definitive.

  27. Dallas said

    Jeff,

    Congrats to you and the crew on the paper. So, has the paper changed your mind on the value of “imputting”? :)

  28. Jeff Id said

    Dallas,

    Thanks. Imputing makes sense in some contexts yet not in others.

    Stan,

    There are enough stations that we see similarity in trend between them over long distances. If we only had 3 or 4 I would have to concede but there are more than that.

    “In Antarctica, the interior coverage is way too sparse and the trends being coaxed from the data are simply too fine.”

    And we conveniently found statistically insignificant trends there. Check the SI.

  29. stan said

    But the lack of statistical significance was not due to the distance between the sites. I don’t care if you find statistical significance between a site in the middle of Africa and a site in the middle of Australia. Doesn’t mean anything (other than a statistical curiosity).

  30. John F. Pittman said

    Happy Holidays, all. JeffID, I got a laugh about your comment of having to learn what other studies said. Perhaps, I am misinformed, but I understood that having to know, or learn past studies was a pre-requisite for peer reveiwed subjects of some contention. I wonder why Dr. Steig did not realize this, especially after the the math course offer. ;)

  31. Jeff Id said

    John,

    Glad to see some got that. Happy holidays as well.

    Stan, Chucking data without reason is equally as bad as accepting it without reason. My primary critique of Mann 08 is chucking data because they didn’t like the look. You don’t ever get to chuck data just because you don’t like it.

    You are allowed to chuck data when specific reasons for bad quality are given and explained. That is why the surfacestations project is so important, it will lay the foundation for chucking what is a considerable amount of bad data.

  32. kim said

    LL, I’ve just suggested at the Bish’s that someone other than Steve McIntyre present the evidence of the aggressively stacked review. My suggestion is that Andy Revkin start earning prizes by covering the story.

    Er, I mean ‘The Story’.

    Wake up, Andy; it’s been a long dream. You’ve got work to do.
    ========

  33. Mark T said

    Never pictured you such the optimist, Kim, or sarcast?

    Mark

  34. Layman Lurker said

    Happy New Year Kim (and all). Maybe it’s just me, but my sense from hearing some of the rumblings and comments since OLMC10 was published is that the Team may find that non “Team” members in the community may not be so submissive or complicit in spinning defenses of S09. Still, I was surprised that Crowley had the cajones to post that comment at Dot Earth as I am sure that he could take an educated guess as to who the reviewer was.

  35. kim said

    It’s both, MarkT; I hope to goad him.
    ===============

  36. Lazlo said

    Please understand everyone that this is all about positioning for AR5, and that this will increase in intensitity over the next year. Eg NH winter chaos due to Arctic warming, now peer reviewed.

  37. [...] course, I’m not so deep in celebration to not read blogs. I have been reading comments about O’Donnell. I plan to post on that after the New Year– mostly commenting on “the spin” coming [...]

  38. I am sure someone can suitably redact the reviewer comments and responses so it can be made public.

  39. stan said

    Jeff,

    Not talking about “chucking data”. When you don’t have enough, you don’t have enough. There’s no law that says we HAVE to compute a trend, even when we lack enough information to compute one that is accurate.

    Over the years, there have been a number of posts at a variety of climate web sites which have shown graphs of the unadjusted temperature histories of various sites around the world. It’s always interesting to me to see how widely divergent the histories can be, even from places that are only short distances apart. This demonstrates that any reconstruction which assumes that the data from any particular station (even assuming perfect quality for the measurements) accurately reflects the temperature history of the surrounding region is operating from a flawed assumption.

    If numbers from site X diverge markedly from sites only 10 or 20 miles away, we can’t confidently assume that the data accurately represents an area that encompasses thousands and thousands of square miles. Take the unadjusted data from four stations chosen at random from the interior of the USA and crunch out a “trend”. How different might that trend be from trends computed for other random groups of four stations? If the trends of any two such groups differ to any serious extent, you have a problem with the basic assumption when you apply it to Antarctica.

  40. Jeff Id said

    Stan,

    I’ve plotted the trends from the Antarctic stations. They are more consistent than the US.

  41. Kenneth Fritsch said

    I’ve plotted the trends from the Antarctic stations. They are more consistent than the US.

    Jeff, if you can show evidence from a PCA that we have a teleconnection here, I would suggest you guys get back together and publish a paper on this feature. As a very nice jester to Eric Steig you could invite him to join you and use his unusual talents to find a physical meaning for the PCA.

  42. Kenneth Fritsch said

    Over the years, there have been a number of posts at a variety of climate web sites which have shown graphs of the unadjusted temperature histories of various sites around the world. It’s always interesting to me to see how widely divergent the histories can be, even from places that are only short distances apart. This demonstrates that any reconstruction which assumes that the data from any particular station (even assuming perfect quality for the measurements) accurately reflects the temperature history of the surrounding region is operating from a flawed assumption.

    Stan, those divergent histories show up in adjusted data also. I think instead of making flat statements here what we need to consider is what these differences do for the uncertainty of estimating trends from sparse, and, in some cases, not well correlated data. I think RyanO at some point indicated he was going to have something to say on this topic with reference to the Antarctica. This is were statistics becomes an important tool to be used, but not an easy tool, in this case, to use – or even I would be providing some estimates.

  43. stan said

    That these four stations happen to have similar trends is totally irrelevant to my point.

  44. kim said

    Heh, ‘jester to Eric Steig’. Funniest thing I’ve read all year.
    =================

  45. Brian H said

    Kim;
    Your compliment was a nice gesture. Unless it was just in jest? That invite would’ve been hard for Steig to ingest, I’d have guessed (i.e., being a guest).

  46. Kenneth Fritsch said

    Heh, ‘jester to Eric Steig’. Funniest thing I’ve read all year.

    That was a nice gesture to a jester and we can leave it to the language policeman to guess whether the “jester” was in the form of a jestered gesture or gestured jester.

    Anyway, I do have to admit that some of those comments by Eric Steig in defense of S09 are difficult to take seriously. I guess his irritation with Steve M stems from Steve pointing to the lack of due diligence on the part of the S09 authors in tracking some of the surface station data. His defense for that one was that Steve M should have known that the error made no difference to their final result. But hey, Eric maybe that lack of due diligence spilt over into your selection of the number of PCs to retain.

  47. Brian H said

    Hm. So, logically, Steig knew in advance that the error he didn’t know he was making wouldn’t make any difference (according to his re-revised analysis which he hadn’t yet done)?

    I see!

  48. kim said

    Gesture Chirrup Cheep
    Everybody knows the Word.
    Eric Jester Steig.
    ===========

  49. kim said

    Smear data on the wall,
    Murky merde Antarktika.
    Raspberry blossoms.
    =======

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