More Mystery at Sheep Mountain

The Sheep Mountain CA bristlecone site is the most important proxy in MBH and the MBH98 reconstruction actually doesn’t differ very much from the Sheep Mountain tree ring chronology (other than it ends in 1980 at pretty much the peak of the Sheep Mt chronology and doesn’t include the downtick in the 1980s.) Various efforts by Mann and his associates to show that they can “get” a HS using various salvage methods do little more than present the bristlecone ring width chronologies up to 1980 in various wigs (borrowing Hu McCulloch’s apt phrase).

A few months ago, I reported that Linah Ababneh’s thesis contained an updated Sheep Mountain chronology which cast the matter in a provocative new light – in which even MBH wigs were of no avail. Here is the comparison that I posted up at the time showing the remarkable “divergence” between the updated Ababneh chronology and the Graybill chronology used in MBH98 (and other studies as well either directly or via the Mann PC1: Crowley and Lowery 2000; IPCC 2001; Mann and Jones 2003; Osborn and Briffa 2006; Hegerl et al 2006; Rutherford et al 2005; Mann et al 2007; IPCC 2007.) Obviously the distinctive HS shape of the Graybill chronology is not replicated in the recent Ababneh chronology. You can view a version of the original Ababneh graphic in this post
if you wish to verify that my plot here (from Hans Erren’s digitization) correctly implements the Ababneh version in her thesis.


Figure 1. Ababneh and Graybill chronologies. Ababneh-black; Graybill -red.

I was doing some calculations to show the Divergence Problem in relation to these chronologies and did a short-segment Mannian standardization of these two series (on the period 1902-1980), yielding the following interesting result. In this perspective, instead of diverging in the period from 1850 on, the two chronologies match rather closely! Despite the seemingly different appearance of post-1840 values in the first plot, they are very similar after 1840 if re-scaled.

abanne48.gif
Figure 2. Ababneh and Graybill Sheep Mt chronologies, standardized on 1902-1980.

So we have a real puzzle? In Figure 1, the Ababneh and Graybill chronologies track each other closely up to about 1840. In Figure 2 (after re-scaling), the Ababneh and Graybill chronologies track each other closely after 1840. Here’s what happens: after 1840, the Graybill chronology is dilated about 186% relative to the Ababneh chronology. It’s almost a linear transformation!

This is really weird, even for dendro. What explains it? I can really only guess. However, it is surely unacceptable in any professional science to have unexplained differences like this – especially in an important series in MBH98 (and one which is even illustrated in IPCC AR4 – based on the Graybill version, of course).

We can eliminate one “explanation” pretty easily: it isn’t CO2 fertilization, since we’re talking ring width measurements at the same site presumably with many of the same trees.

One possibility is that Ababneh screwed up her chronology calculations. This seems unlikely as these calculations are pretty much canned calculations given the measurement data. These results were presented as the major part of her PhD thesis and in a recent “peer reviewed” journal article. Did anyone on her thesis committee at the University of Arizona (including Malcolm Hughes) check her calculations? While one doesn’t expect mistakes to be made with canned programs, things happen. Checking would only take about 20 minutes to do given the measurement data. Or maybe calculations aren’t checked in University of Arizona PhD theses. In her thesis, she says that she will archive her data at ITRDB, but nothing has been archived so far. I guess the dendros didn’t check that either. The University of Arizona claims not to have the data.

I have no reason to believe that her calculations are incorrect, but that leaves the dilation relative to the Graybill chronology unexplained. Should the thesis committee have asked for this to be explained in her thesis? This occurred to me immediately. Malcolm Hughes knows the Sheep Mountain chronology – it was an issue in our MBH criticisms. Why didn’t he ask that she deal with this. But, hey, it’s climate science.

The most likely difference is due to populations. Ababneh used 100 trees in her calculation – which is larger sample than that which Graybill archived. Maybe the Graybill sample was not representative. At Almagre, we found that Graybill did not archive all of the measured trees – only a subset. Nobody ever mentioned this in any literature. Is the Graybill chronology based on a specially tailored subset? This is possible: Graybill was looking for data to support his theory of CO2 fertilization and in Graybill and Idso 1993, he said that they selected strip bark trees. Maybe this explains the difference. Or maybe the Graybill sample was simply too small. Who knows? There’s no proper data archiving, no proper analysis. It’s a typical MBH mess.

What we do know is that we have inconsistent versions of the Sheep Mountain chronology – versions that are different on the key issue of medieval-modern relationships. In the Graybill version (as applied by Mann), the California “sweet spot” had bitter cold in the MWP; for whatever reason, Ababneh didn’t replicate this result.

Until the University of Arizona provides a proper explanation of the present fiasco in their Sheep Mountain records, I do not believe that any of these chronologies can be validly used in a temperature reconstruction. End of story. All calculations using Graybill’s Sheep Mountain (and Campito Mountain etc.) chronologies should be frozen and put on the sidelines until the matter is resolved – just the way a professional organization would do it.

Sure Mann can claim till he’s blue in the face that he can “get” a HS from Graybill chronologies and the rest of the MBH network using RegEM or whatever, but, as Mann himself observed some time ago, “Garbage In, Garbage Out”. If the Graybill chronologies are garbage – and until the difference with Ababneh chronologies is resolved and the Graybill chronologies validated, they must be treated as though they were garbage – MBH98, (Rutherford et al 2005, Mann et al 2007, etc.) calculations using Graybill chronologies are also unusable. Or to use Mann’s term, “garbage”.

UPDATE: Here’s an interesting figure which shows the Ababneh reconstruction scaled to match the Graybill reconstruction in the Mannian calibraiton period of 1902-1980, which vividly illustrates an interesting statistical point that I discussed in connection with Juckes – that you can have reconstructions that are virtually indistinguishable in their calibration and “verification” results with very different trajectories off in the earlier portion of the reconstruction, asking how can you objectively say that one is “right” and another “wrong”.

Here’s the Ababneh chronology rescaled to match the Graybill chronology in its recent history (I’ve used the early portion of the Graybill chronology to provide the “extension” to the Ababneh chronology.) As in Figure 2 (which is identical to Figure 3 in the latter portion), the Ababneh and Graybill chronologies are indistinguishable in terms of calibration (1902-1980) period appearance. But they are also virtually identical in the “verification period” back to 1850 – the divergence between the two series occurs either before 1840 (with Ababneh having a greater proportion of thick ring widths in the early history) or after 1840 (with Ababneh having a greater proportion of thin ring widths in the later history) – or some processing difference. Regardless of which chronology is “right”, for the multiproxy statistician – who is constrained by the “peer reviewed” time series squiggles emanating from the University of Arizona – there is no objective way of picking one version rather than the other.

abanne49.gif


123 Comments

  1. Ron Cram
    Posted Jan 31, 2008 at 11:57 AM | Permalink

    WOW!

    Fascinating stuff, Steve. Like you said, there is no way to know exactly what happened, but your idea the Graybill sample is not representative seems to me to be most likely. Why the thesis committee did not dig into this issue is baffling. I assume U of Arizona is accredited by the Western Association of Schools and Colleges. I wonder how they would feel about the program not checking into such an obvious discrepancy?

  2. Mike B
    Posted Jan 31, 2008 at 12:19 PM | Permalink

    Until the University of Arizona provides a proper explanation of the present fiasco in their Sheep Mountain records, I do not believe that any of these chronologies can be validly used in a temperature reconstruction. End of story. All calculations using Graybill’s Sheep Mountain (and Campito Mountain etc.) chronologies should be frozen and put on the sidelines until the matter is resolved – just the way a professional organization would do it.

    All the proxy series are going to have noise. Some of them may be mostly noise. I’d settle for using a “garbage”seriews like Sheep Mountain as long as the methods provided results robust to their inclusion. Kicking Graybill to the curb is a bit much; kicking Mannian PCs or their various wigs to the curb is fine.

    One nit, the top graph has Abanah in black and Graybill in red. The bottom graph has them reversed.

  3. Peter D. Tillman
    Posted Jan 31, 2008 at 12:22 PM | Permalink

    Thanks for being persistent on this, Steve. It’s an important problem, and it’s remarkable that a respected professor at a world-renowned laboratory would continue to ignore such a problem. Time for another of my oh-so-effective letters? ;-)

    Amusing sidelight: at the LTRR website http://www.ltrr.arizona.edu/research.html , the “dendroclimatology” link is dead!

    From Malcolm Hughes UA webpage http://www.ltrr.arizona.edu/people/8 : ““How and why does climate vary on interannual to century time scales?.” I view this as the central question of what I call “meso-climatology”… I focus on building large scale (continental to global) networks of instrumental and ‘proxy’ climate records with defined chronology, temporal resolution and climate signal.”

    Cheers — Pete Tillman

    • AK
      Posted Jan 31, 2008 at 12:58 PM | Permalink

      Re: #3

      Actually, only two out of 9 “Research Interests by Subdiscipline” are links (dendroarchaeology and dendroecology), the rest are only titles.

  4. Steve McIntyre
    Posted Jan 31, 2008 at 12:32 PM | Permalink

    I’ll have to take your word on #3. The University of Arizona has blocked access to the ltrr.arizona.edu website from my IP address. Buncha jerks.

  5. Pat Frank
    Posted Jan 31, 2008 at 1:01 PM | Permalink

    The Graybill and Ababneh series pretty much wiggle-match after 1840, no matter that there is a difference in slope. If they were smoothed, and the first derivatives taken, it looks like the derivatives would pretty much be a match. In fact, that looks to be true over the entire data sets. A match in derivatives of complex data sets equivalently derived implies that they reflect pretty much the same underlying physical phenomenon. The likelihood of identical inflections occurring across physically disjoint time series seems vanishingly small. That being true, then the difference after 1840 is just a smooth artifactual offset. One looks for something in the data processing to explain this sort of difference, or a traceable change (or error) in experimental method.

    Second, in Figure 2, after your re-processing, Steve, the new superposition of the two data sets after 1840 is accompanied by a new divergence of them prior to 1840. Whatever you did to converge the post-1840 data diverged the pre-1840 data. This seems to imply that the difference between the original data sets is not linear. It looks more like one of the two data sets was multiplied (or divided) by something that looks like a Gaussian tail — an exponential.

    Figure 2 only goes back to 1725 or so. Does the divergence now prior to 1840 continue to increase all the way back to 1200, or is the Graybill-Ababneh difference a constant offset? Also, what does the difference between the two original data sets look like? Like a long-tailed Gaussian section?

  6. Jim Arndt
    Posted Jan 31, 2008 at 1:02 PM | Permalink

    Hi,

    I may be wrong but aren’t tree rings mostly affected by rain fall and not so much by temperature?

  7. Pat Frank
    Posted Jan 31, 2008 at 1:07 PM | Permalink

    #4 — intellectual cowards and violators of scientific ethics, more like. Hardly the attitude toward free and honest inquiry we like to see in a university.

  8. CWells
    Posted Jan 31, 2008 at 1:13 PM | Permalink

    Why worry, the fight is over….
    The media is fully behind AGW, Algore has the Nobel, and now Bill ‘the Groper’ Clinton is expressing the globalony view that my children need to be less prosperous to save the planet…….

    http://blogs.abcnews.com/politicalpunch/2008/01/bill-we-just-ha.html

    Though I know full well that this is an analysis blog, from which I have learned much more than I could ever repay, these small battles, fought and won here, are not in the big picture going to do much if this information is not somehow concisely put together, ie, in a bullet like format, and diseminated as widely as possible.
    For example, the true time line of Mann’s refusals to provide data, Thompson’s refusal to disclose updates on the glacial information, IPCC’s lack of true ‘review’, Hansen’s refusal to fully define ‘adjustments’, timeline of temperatures versus the addition and deletions of various adjustments, mechanisms, movements of stations, etc. Et al…..
    Sorry to be soooo off topic (and negative) on this particular issue. (I have loved following the analysis of these very types of data.) Perhaps an unthreaded so I can ask some dumb questions, get contributor help in finding some of this information..call it Rise of the Modren Luddites.
    Thanks for your patience,
    CWells

  9. Larry
    Posted Jan 31, 2008 at 1:18 PM | Permalink

    Is Gavin going to ignore this, or give us a tapdance?

  10. Andrew
    Posted Jan 31, 2008 at 1:51 PM | Permalink

    Pat Frank,

    The Graybill and Ababneh series pretty much wiggle-match after 1840, no matter that there is a difference in slope. If they were smoothed, and the first derivatives taken, it looks like the derivatives would pretty much be a match.

    How can the derivative match if the slope is different (puzzled here)?

  11. pk
    Posted Jan 31, 2008 at 2:16 PM | Permalink

    I think it’s the difference in the trees. The Ababneh data in your first figure is the aggregated data Patriarch Grove and Sheep Mountain using an even mix of whole and strip bark. If you go back to the original Ababneh thesis and look only at Sheep Mountain strip bark, it looks like it would be much more comparable to Graybill, who selected mostly strip bark.

  12. Larry
    Posted Jan 31, 2008 at 2:34 PM | Permalink

    6, keep in mind, that even if the ups and downs match reasonably well, that doesn’t mean that the ups and downs represent temperature.

  13. Pat Frank
    Posted Jan 31, 2008 at 3:08 PM | Permalink

    #11 — Andrew, the derivative of a straight line of positive slope is a positive constant, i.e., a new horizontal straight line with all the points equal to the value of the slope of the original tilted line.

    So, if the Graybill data differs from the Ababneh data just by some ascending straight line, taking the derivatives will remove the tilted slope and replace it with a small constant offset equal to the slope of the previous tilt. All the wiggles in the two derivatives would now linearly track one another, if the two series reflected the same process.

  14. Pat Frank
    Posted Jan 31, 2008 at 3:13 PM | Permalink

    #13 — Larry, that’s for sure. That exact point has been made in CA many times, and often by me. There is no physical theory that will extract a temperature from a tree ring (I proposed an approach to one on CA, though). The whole dendrothermometry field is based on extracting a quantitative measure from a qualitative judgment. It’s rife with a superficially impressive but completely false precision.

  15. Craig Loehle
    Posted Jan 31, 2008 at 4:06 PM | Permalink

    If the Graybill series are mostly strip barks, this would explain the puzzle. A strip bark tree has a narrower (not full trunk) band of bark, which is exhibiting compensatory growth (there is more roots and leaves in proportion to cambium area, so the tree is trying to adjust the proportions). The ring width on the strip bark will be a multiple of the normal, just as you see, with the most difference when the trees are growing best.

    Steve: The Graybill series are mostly strip bark as we noted in our 2005 articles. My guess is that that’s not the only issue. You’d think that the people who are reporting these chronologies would describe this in their reports, wouldn’t you?

  16. Demesure
    Posted Jan 31, 2008 at 4:30 PM | Permalink

    The link to UA’s Tree ring lab http://www.ltrr.arizona.edu/ is dead for me to.

  17. Anthony Watts
    Posted Jan 31, 2008 at 4:35 PM | Permalink

    “Mystery at Sheep Mountain” …sounds like a Hardy Boys or Nancy Drew book. Of course the heroes always solved the mystery. Looks like Steve is well on his way.

    Steve:
    Yes, indeed. I didn’t even have to look up Franklin W. Dixon. The Hardy Boys seem to have dropped off the landscape; my kids never read any and they seem impossibly old-fashioned for my grand-daughter in the aspiring Hannah Montana generation. But I read them voraciously when I was about 7-9.

  18. woodentop
    Posted Jan 31, 2008 at 4:53 PM | Permalink

    Steve #4 – are you sure you have the correct link? It seems to be missing the www prefix and doesn’t work for me. The link in #17 works fine.


    Steve
    Doesn’t work for me. Hasn’t for a while. I used a trial version of anonymizer software a while ago and got through and have got through from the U of Toronto library.

  19. Tom Gray
    Posted Jan 31, 2008 at 4:56 PM | Permalink

    re 3

    I’ll have to take your word on #3. The University of Arizona has blocked access to the ltrr.arizona.edu website from my IP address. Buncha jerks.

    It is dead for me as well but http://www.ltrr.arizona.edu is alive and well

  20. Geoff Sherrington
    Posted Jan 31, 2008 at 6:33 PM | Permalink

    Re #16 Craig Loehle

    On strip barks. (BTW, I enjoy your contributions here).

    You infer that sampling frequencies of strip bark and unaffected trees gives the difference observed since about 1840 when the divergence starts. For this explanation to apply, surely, one would have to assume that no strip bark process happened and influenced results prior to 1840. It is hard to believe that all the trees were entire from 1100 ad to 1840, then some suddenly developed strip bark from 1840 onwards. The divergence is possible, I concede, if strip bark trees die and disappear within about 150 years after being affected.

    Steve, I continue to be amazed by the continuing use of data derived from suspect sources (strip barks). You can add my name to the petition for putting these data on hold until resolved. I can get the Uni website from here, I’ve not been barred yet.

    ..

  21. John A
    Posted Jan 31, 2008 at 6:58 PM | Permalink

    I must say I’m unimpressed by the quality of PhD theses at the University of Arizona.

  22. Posted Jan 31, 2008 at 7:26 PM | Permalink

    Where’s this famous Sheep Mountain? There’s a Sheep Mountain National Forest between San Bernardino and Palm Springs that incorporates Mount Baldy and is supposed to have good hiking, relatively above the smog. Same area?

    Incidentally, the “wig” alluded to in the post was not created by Mann, but by Al Gore, when he disguising Mann’s HS and passed it off as an ice core series. By splicing the Jones et al 1999 annual instrumental series onto Mann’s HS, Gore created a distinctive series with a long, flat left end, but with a bushy false beard and spike hairdo at the right end that made it hard to recognize, even by seasoned climato-sleuths.

    I just got ahold of a copy of the print version of AIT. It turns out that Gore presents the bogus “Dr. Thompson’s Thermometer” twice, once on p. 63 in its original vertical position, and then in greater glory on pp. 64-65, as a 2-page spread. For some reason, the second version is credited to IPCC.

  23. Posted Jan 31, 2008 at 8:33 PM | Permalink

    There are no units on the vertical axes in Figures 1 and 2, so presumably these are z-scores relative to some reference period. In Figure 1, there is no explicit reference period, but they coincide up to about 1840 and then diverge afterwards. In Steve’s Figure 2, the reference period is explicitly 1902-80, and they diverge before 1810. So maybe it’s just a difference in reference period, and the one series is indeed just a linear dilation of the other, to within measurement error.

    What happens when both are normalized relative to say 1100-1980 or 1740-1980? Are there any objective units in which to measure tree rings?

    Steve: Tree ring chronologies are conventionally reported in standardized units. A smooth curve (in this case probably negative exponential) is conventionally fitted to the trees and is asserted to represent aging effect and a ratio between the observation and the standard calculated. The chronology is the average of these ratios across trees of different starts and ends. Statistically it’s a calculation that’s quite interesting, but the usual recipes have quite a bit of hair on them IMO.

  24. Posted Jan 31, 2008 at 8:48 PM | Permalink

    Sheep Mountain is in the White Mountains which are northeast of Bishop, California near the Nevada border.

  25. SteveSadlov
    Posted Jan 31, 2008 at 8:49 PM | Permalink

    RE: #7 – My bet is, they are a proxy for snow pack persistence. If the snow pack persists sufficiently to provide ample moisture in July and early Aug, the trees do well that year. If the pack does not persist long enough, the trees go dry during the critical period. Those who are intimately familiar with E California and W Nevada will recognize what I mean.

  26. Posted Jan 31, 2008 at 9:19 PM | Permalink

    In #25, theduke writes,

    Sheep Mountain is in the White Mountains which are northeast of Bishop, California near the Nevada border.

    There’s a nice view of what must be these mountains, from across the Owens valley, at

    http://en.wikipedia.org/wiki/Inyo_County:

    Which one is Sheep Mtn?

  27. Posted Jan 31, 2008 at 9:22 PM | Permalink

    Try again:

  28. Posted Jan 31, 2008 at 9:52 PM | Permalink

    On further “researching” (wikisearching, in fact) the White Mountains, it appears that perhaps this scene is from the White Mountains, perhaps from The Sheep itself. See http://en.wikipedia.org/wiki/Owens_Valley, esp. .

  29. Steve McIntyre
    Posted Jan 31, 2008 at 10:10 PM | Permalink

    http://www.virtualguidebooks.com/SouthCalif/EastOfTheSierra.html has many background photos. I’ve collected some very interesting site info on old roads in the bristlecone areas, by searching on mining ghost towns from the 19th century.

    There are some great panoramas at this website. This panorama shows dead bristlecones above the present treeline http://www.virtualguidebooks.com/SouthCalif/EastOfTheSierra/Patriarch/DeadBristlecones.html -great web presentations.

  30. Yancey Ward
    Posted Jan 31, 2008 at 10:16 PM | Permalink

    Wow, I never realized how close in distance Mt. Whitney is from Death Valley. Amazing!

  31. Posted Jan 31, 2008 at 10:17 PM | Permalink

    Circa 37d 23’N, 118d 11’W, Google Earth has photos of several dead-looking “oldest living thing” BCP’s. You can see individual trees from space. Nearby cul-de-sac is BCP Forest Visitor Center.

  32. ferris
    Posted Jan 31, 2008 at 10:19 PM | Permalink

    I used a trial version of anonymizer software a while ago and got through and have got through…

    Use Tor, it’s free.

    http://www.torproject.org/

  33. Posted Jan 31, 2008 at 10:24 PM | Permalink

    I guess Mt. Whitney is the high point about 1/4 of the way from L to R in the panorama shot of the Sierra Nevada?

  34. dendro
    Posted Jan 31, 2008 at 10:25 PM | Permalink

    Science is self-correcting. We don’t need your help. Thanks.

  35. Raven
    Posted Jan 31, 2008 at 10:30 PM | Permalink

    dendro says:

    Science is self-correcting. We don’t need your help. Thanks.

    We don’t have time to wait for science to “self-correct” if the science in question is being used to justify trillions $ in public policy changes.

  36. Steve McIntyre
    Posted Jan 31, 2008 at 10:39 PM | Permalink

    Science is self-correcting.

    Dendroclimatology isn’t self-correcting.

    Ergo, there is only one possible conclusion.

  37. conard
    Posted Jan 31, 2008 at 11:05 PM | Permalink

    Raven,

    We don’t have time to wait for science to “self-correct” …

    I have objected elsewhere to the “time is up” argument from the “science-is-settled” side and object to its use from the “science-is-not-settled” side. This is the bread and butter of a con-artist not well reasoned discourse.

  38. Steve McIntyre
    Posted Jan 31, 2008 at 11:08 PM | Permalink

    No more of this baiting type of discussion here please.

  39. Pat Frank
    Posted Feb 1, 2008 at 12:11 AM | Permalink

    As a working scientist I can say without qualification that Steve’s work *is* science correcting itself. Ross’, too, for that matter. Science is the process not the person.

  40. Bill F
    Posted Feb 1, 2008 at 12:56 AM | Permalink

    Steve,

    Its becoming more and more apparent that the UA motto needs to be changed to “what happens at Sheep Mountain STAYS at Sheep Mountain”. Keep up the good work!

  41. Andrey Levin
    Posted Feb 1, 2008 at 4:29 AM | Permalink

    Can’t fight the temptation to reproduce one recent joke.

    What is the difference between science and climate science? Same as between economics and political economics.

  42. D. Patterson
    Posted Feb 1, 2008 at 4:41 AM | Permalink

    What is the difference between science and climate science? Same as between economics and political economics.

    I thought the punchline was going to be: two degrees of separation….

  43. pk
    Posted Feb 1, 2008 at 5:42 AM | Permalink

    A few snippets from Ababneh’s dissertation:

    A premise in this study is, if strip-bark trees and whole-bark trees have a similar
    increase in tree-ring width after 1850, then tree-ring chronologies should not show any
    deviation from each other at any certain time interval. Analysis, however, shows that
    strip-bark tree chronologies with both averaged and normalized (z-score) tree-ring widths
    show a steeper increase in tree-ring width compared with whole-bark trees.

    …..

    This result emphasizes the importance of plotting all of the
    individual core samples with robust means and a mean of zero (Figures 8-11). The
    increase in sample size over that of Graybill and Idso permitted a more robust evaluation
    of differences in growth rates between strip-bark and whole-bark trees.

    …..

    This shows how inadequate sampling might lead to different conclusions.

  44. Bill F
    Posted Feb 1, 2008 at 7:17 AM | Permalink

    I am surprised that thesis made it past Hughes with those statements in it. It would appear that she is drawing the conclusion that Graybill had an insufficient sample size and that the strip bark trees in his sample skewed his results. No wonder she needs a lawyer…she is taking shots at the foundation of the hockey stick in a thesis. Gutsy…

  45. Steve McIntyre
    Posted Feb 1, 2008 at 8:38 AM | Permalink

    I’ve changed the coloring in Figure 2 to match Figure 1. I’ve added a new Figure extending Figure 2 back to 800 AD and illustrating an interesting statistical point that I’ve mulled over on other occasions. The Ababneh and Graybill chronologies not only march in virtual lockstep during the Mannian calibration period 1902-1980; they also march in lockstep through the Mannian verification period. They only diverge (under this scaling) prior to about 1840. Is there any objective way for a multiproxy statistician to say that the Graybill chronology is “right” and the Ababneh chronology is “wrong” using calibration and verification statisitcs? I don’t think so. And yet they yield different answers. I’ve observed this conundrum in other contexts but this is a terrific example of the problem in an influential series that we’ve been following for a long time.

  46. Posted Feb 1, 2008 at 8:42 AM | Permalink

    RE #46,
    Is it possible to plot both in treering width units rather than artifically standardized units? I gather treering widths ordinarily vary in a certain way with tree diameter, so that one ordinary looks at residuals from some empirical formula. But still, what happens when the same formula is used throughout history and for both data sets?

  47. Steve McIntyre
    Posted Feb 1, 2008 at 8:56 AM | Permalink

    #47. Hey, Hu, I’d love to look at the Ababneh ring width data. But it’s not available (on the advice of her lawyer apparently.) Here’s a post
    http://www.climateaudit.org/?p=478 where I calculated ring widths for a site (as opposed to the conventional “chronologies”). It had an interesting result that the upper site had wider ring widths than the lower site, something not observed in literature. Graybill’s measurement data is at ncdc.noaa.gov/paleo as series ca534.rwl.

    BTW I entirely agree about looking at residuals. I’ve done lots of work trying to think about ring width “chronologies” statistically. I did some very interesting analyses emulating chronology methods using linear mixed effects models (nlme) so it is possible to place the local recipes in a format intelligible to the statistical community off the Island. It would be an excellent paper – one that’s worth writing up. I was thinking about this matter about 6 months before I started the blog so my notes on the topic are not online.

  48. SteveSadlov
    Posted Feb 1, 2008 at 10:19 AM | Permalink

    RE: #28 – That brings back some fine memories. My senior project field study area.

  49. SteveSadlov
    Posted Feb 1, 2008 at 10:22 AM | Permalink

    RE: #34 – Yes, that is looking across the northern end of the Owens Valley, at the High Sierra. IIRC – Whitney is the peak shrouded in clouds.

  50. Posted Feb 1, 2008 at 11:41 AM | Permalink

    OT: the world’s most brutal marathon races runs from Death Valley to Mt. Whitney:

    http://www.badwater.com/

  51. Pierre Gosselin
    Posted Feb 1, 2008 at 11:45 AM | Permalink

    I earned my BS in Mechanical Engineering at the U of A…how embarassing!

  52. Otto
    Posted Feb 1, 2008 at 11:59 AM | Permalink

    So we have a real puzzle? In Figure 1, the Ababneh and Graybill chronologies track each other closely

    up to about 1840. In Figure 2 (after re-scaling), the Ababneh and Graybill chronologies track each other closely after 1840. Here’s what happens: after 1840, the Graybill chronology is dilated about 186% relative to the Ababneh chronology. It’s almost a linear transformation!

    This is really weird, even for dendro. What explains it?

    Maybe, if you have two time series that closely track each other and then diverge at the end (Fig 1 above), in the act of transforming the data to Z scores based on the means of the end (divergent) part you use very different means for each transformation and thus force the data together at the end and apart at the beginning (as in Fig. 2 above).

    Steve: Maybe. Maybe not. Isn’t that the sort of thing that Malcolm Hughes and the University of Arizona should have sorted out during the PhD process and been sorted out prior to “peer reviewed” publication?

  53. Larry T
    Posted Feb 1, 2008 at 12:07 PM | Permalink

    I am by training/work a mathematician and my more recent work as computer scientist contractor for state and federal government agencies. A lot of my worked involved data analysis and my pattern recognition skills help pinpoint errors in either data or processes. I look at the first graph and see a definite pattern in the chronologies that show a divergence in the data post 1850. The data is the put through the “Mannian” process and snow shows a divergence pre-1880. If this was my work i would immediately suspect that I had a programming error in my process and start immediately to try to debug the process. This does not necessarily mean that there is an error in the process but it does mean that the process must be certified to be working correctly. The code that i have looked over mostly Hansen not Mann was very amateur and the data analysis of input and intermediate results was abysmal. If “Doctor” Hansen was my student i’d given him an “F” and advice to take up another line of work.

    Steve: None of this data is Mann-processed. This is pre-Mann. Mann used the Graybill chronology and the Mann process resulted in heavy weighting for the Graybill bristlecone chronology which then became the HS. But Mann, despite his other sins, did not create this data.

  54. Bill
    Posted Feb 1, 2008 at 12:30 PM | Permalink

    Re: #30, panorama shows dead bristlecones above the present treeline”

    This is an elegant statement, to me as close to proof as anything I can grasp. While watching the slow pan, I wondered if there has ever been an “answer” to it.

    Robert Crease is an author who compiled other scientists’ nominations for what he called Science’s 10 Most Beautiful Experiments. http://physics-animations.com/Physics/English/top10.htm

    WRT #9, CWells’ magic bullet:

    Climatology seems ripe for a few of these elegant proofs, irrefutable and obvious, even to us non-scientists.

  55. Peter D. Tillman
    Posted Feb 1, 2008 at 12:38 PM | Permalink

    Re Pierre, #52, UA decline

    The really sad thing is, the UofA is where dendrochronology was invented : http://www.lowell.edu/Research/library/paper/ae_douglass.html

    http://www.ltrr.arizona.edu/history.html

    Huh. I’d forgotten he started out as an astronomer.

    Is Hughes the only bad apple at LTRR?

    Re #5, http://www.ltrr.arizona.edu/research.html

    That’s an odd page, isn’t it? Like someone started a fancy page & lost interest. Curious.

    Cheers — Pete Tillman, ex-Tucson resident, for almost 30 years (off & on)

  56. Peter D. Tillman
    Posted Feb 1, 2008 at 12:45 PM | Permalink

    Re #55, Re: #30, panorama shows dead bristlecones above the present treeline”

    “This is an elegant statement, to me as close to proof as anything I can grasp. While watching the slow pan, I wondered if there has ever been an “answer” to it.”

    I presume they’ve been dated, but a reasonable guess is they are relicts of the MWP, or at least the last time the climate was more equable for BCP’s here. Dead trees can last a long time where it’s cold & dry. Cite, anyone?

    TIA & Cheers — Pete Tillman

  57. Steve McIntyre
    Posted Feb 1, 2008 at 12:52 PM | Permalink

    #57. These high treelines are very interesting. I did a post a couple of years ago with a picture of a fossil foxtail above treeline in the Sierras and have collected treeline references from time to time. A full updated survey of treeline information is really needed.

    It doesn’t settle things as much as you might think. Treelines take time to respond, are climbing during the 20th century and are probably below their equilibrium altirude at present temperatures. Is that equilibrium altitude above the subfossil treeline (which is often from the Holocene Optimum rather than the MWP? That argument’s been made; at this point, I have no opinion on how good such calculations are.

  58. Jim Arndt
    Posted Feb 1, 2008 at 1:10 PM | Permalink

    Steve,

    It might be interesting to see precipitation chart for the same time period. If I am correct they will also show an increase during the 20th century.

  59. Otto
    Posted Feb 1, 2008 at 1:33 PM | Permalink

    Re #53 Steve, perhaps I misunderstood. I thought Fig. 1 was the original data and Fig. 2 was the data transformed by your standardization procedure which (depending on how it is done) may cause the divergence to disappear at the end and appear earlier.

  60. Steve McIntyre
    Posted Feb 1, 2008 at 2:01 PM | Permalink

    The tree ring “standardization” was done by the original authors. I obviously don’t have Ababneh data and am working with digitization of her chronology. I’m working with a digital version of the Graybill chronology. It’s quite possible that there is some unreconciled difference in procedures between Graybill and Ababneh, but it’s nothing to do with any handling at my end. The discrepancy is the property of the University of Arizona.

  61. SteveSadlov
    Posted Feb 1, 2008 at 2:10 PM | Permalink

    RE: #51 – It’s actually only to Whitney Portal, ~ 8 or 9K feet. Of course, someone will make it more extreme at some point, and run it right up to Whitney, 14.5K ft.

  62. KevinUK
    Posted Feb 1, 2008 at 2:10 PM | Permalink

    Steve

    I’m trying to resist the temptation to slip into a mode that I’ve been in on sevearl occasions in the the past when posting here.

    That mode is that all this dendro stuff is an utter waste of time. Please convince me otherwise. From what I can see here this looks like we are having a debate over how best to manipulate proxy data so that it shows a different medieval v modern warming relationship depending on how you manipulate it. This has always been at the crux of the matter IMO. This IMO is what the entire HS debacle was all about.

    The Script:

    Somewhere in an office on the University of Pittsburgh campus.

    Anonymous politico: ‘How do we get rid of the MWP’

    Malcolm Hughes: ‘Well I know of a tree ring series in Socal that shows a preciptation signal that favours the modern over medieval period? To boot if we choose only the strip bark samples it flattens out the MWP signal even more.

    Michael Mann: ‘I know a statistical trick (sorry meant technique) involving de-centering and preferential selection of proxy series that shows a modern precipitation signal (sorry I meant temperature signal) relative to medieval period signal’. It’s a novel technique so no one will pay that much attention (unless they are Canadian). I reckon that with a bit of fiddling (sorry i meant luck) we’ll be able to show that the modern precipitation signal (sorry I meant temperature) is unprecented in the last millyun years. I reckon we can get a few of our mates to do the peer review and it’ll sail into publication with Steve Schneiders help no problem. You never know with a further bit of manipulation (sorry I meant luck) the IPCC will latch onto it and use it as the poster child for the IPCC TAR. What do you think Malcolm?

    Malcom Hughes: ‘But what about the divergence problem?’

    Phil Jones: ‘That’s a no brainer Malcolm. We’ll just stop before then and splice on the instrumented temperature anomaly and then it’ll look just like a hockey stick. The IPCC will love it and we’ll be guaranteed funding for our departments for at least the next 30 years.

    Anonymous politico: ‘Brilliant! Lets do it’.

    Regards

    KevinUK

  63. SteveSadlov
    Posted Feb 1, 2008 at 2:24 PM | Permalink

    MM: Plus, it would appear that ever since the 1800s, snow pack persistence in the White Mountains has increased. These trees at the edge of the major summer time semi stationary high pressure zone, are lucky to get a summer time gully washer. Years without good snow pack persistence they are nearly dormant, even in high summer.

    MH: Mike, you are onto something here. I’ve also noticed that, as well as one other critical thing. It would appear that during the MWP, there were fewer Tonopah Lows than during either the current warm period or the LIA. That means, poor growth that entire time. Nice, flat, low growth curve, nice hockey stick handle, dude!

  64. Larry T
    Posted Feb 1, 2008 at 2:36 PM | Permalink

    Steve, I was more speaking to intermediate results from Mann. The problem that was very evident that should have definitely been resolved before any publishing of using this data was that the fact the missing values insertion resulted in massive changes to other data points was an error flag of massive proportions. Anyone who manages to get a major science doctorate degree (and maybe those with just a B.S.) is by definition much smarter (but not necessarily wiser) than a poor mathematician/computer scientist with only a graduate certificate. I am more used to dealing with data that was to double precision accuracy rather trying to pull a .1 degree signal out of data measured to a degree of accuracy. NASA was the longest organization i contracted with.

  65. Larry T
    Posted Feb 1, 2008 at 2:40 PM | Permalink

    oops and my main person i have problems with and data/code i looked at were Hansen not Mann.

  66. Peter Thompson
    Posted Feb 1, 2008 at 2:57 PM | Permalink

    This is ripe for snipping, but as a proud Canadian and decent hockey player in my youth, it has often crossed my mind that American hockey teams often come to regret the day they thought they could survive an encounter with us.

  67. Alan S. Blue
    Posted Feb 1, 2008 at 3:01 PM | Permalink

    The snowfall this year is so amazingly tremendous farther north. Are the mountains in northern California also receiving massive snowfalls?

    Because this year’s treerings should have definitive comparisons versus precipitation/snowpack. You’d have both the extreme lack of snow a couple of years ago (2004? 05?) as well as the snowpack of 2008 – which can’t help but last well into the summer.

  68. steven mosher
    Posted Feb 1, 2008 at 3:21 PM | Permalink

    67. center ice hose head!
    [snip] Way off topic.

  69. steven mosher
    Posted Feb 1, 2008 at 3:27 PM | Permalink

    [snip] Off topic.

  70. SteveSadlov
    Posted Feb 1, 2008 at 3:29 PM | Permalink

    RE: #68 – personal observation, made last weekend in Douglas County NV (just east of the Cali border) – 10 ft snow pack, more on the way. And unlike last year, where the pack was powder, with no interbedding of wetter snow (and therefore subject to blowing / sublimating literally into thin air) , this year has the interbedding – the pack in not only much more massive but is also much more robust. Powder comes from Tonopah Lows and Siberia Express type systems, wetter interbedding come from the rare more zonal, mT rich systems that somehow sneak past the Sierra Nevada.

  71. deadwood
    Posted Feb 1, 2008 at 4:15 PM | Permalink

    mosher @70:

    Did they ever get the Order of Canada?

  72. Curt
    Posted Feb 1, 2008 at 4:29 PM | Permalink

    Alan #68:

    I heard on the radio news this morning (NPR) that the Sierra snowpack is over twice what the average for this time of year is. They of course immediately followed this snippet with another one stating that global warming has been causing this snowpack to melt progressively faster over the last 50 years. I haven’t had the chance to look into either report.

  73. Jim Arndt
    Posted Feb 1, 2008 at 4:42 PM | Permalink

    Curt 73

    Averages in California are 111% to 123% above normal, but the majority of where we get our water from they can’t even access it, too much powder from the last storms.

  74. Posted Feb 1, 2008 at 5:39 PM | Permalink

    SteveSadlow, Re #62: until 1990 the race was run to the peak. There’s a fascinating history of the race at that website. The first guy to do it Al Arnold, was a wildman.

    http://www.badwater.com/stories/2002/2002wallack.pdf

  75. Otto
    Posted Feb 1, 2008 at 5:46 PM | Permalink

    Steve at #61 you say:

    The tree ring “standardization” was done by the original authors. I obviously don’t have Ababneh data and am working with digitization of her chronology. I’m working with a digital version of the Graybill chronology. It’s quite possible that there is some unreconciled difference in procedures between Graybill and Ababneh, but it’s nothing to do with any handling at my end. The discrepancy is the property of the University of Arizona.

    Now I realize the original tree ring ridth measurement data were “standardized” by the collectors. What I wonder about is your figure 2 above. Where did that come from? You say:

    I was doing some calculations to show the Divergence Problem in relation to these chronologies and did a short-segment Mannian standardization of these two series (on the period 1902-1980), yielding the following interesting result.

    My point in #53 above is that the “mystery” of your figure 2 could have been created by your “short-segment Mannian standardization of these two series (on the period 1902-1980)”

    Maybe, if you have two time series that closely track each other and then diverge at the end (Fig 1 above), in the act of transforming the data to Z scores based on the means of the end (divergent) part you use very different means for each transformation and thus force the data together at the end and apart at the beginning (as in Fig. 2 above).

    Steve: Nope. You’re missing the point entirely.

  76. DocMartyn
    Posted Feb 1, 2008 at 8:47 PM | Permalink

    About the dead tree at high elevation.

    As anyone ringed it and aged it, using both dendochorology and C14 dating.
    I know it is an obvious question, but I must have missed it.

    Steve: I’ve discussed above treeline BCPs previously. Some date from the MWP; some date from the Holocene Optimum etc.

  77. Anthony Watts
    Posted Feb 2, 2008 at 3:08 AM | Permalink

    This may be a stupid question, and if so don’t be shy about pointing that out. I’ll be the first to admit that I know little about dendrochronology.

    Is there experimental data on Bristlecone tree ring growth under controlled environment (such as a greenhouse) that establishes without a doubt that one or more of the following is true or false?

    – Bristlecone growth responds proportionately to temperature
    – Bristlecone growth responds proportionately to humidity
    – Bristlecone growth responds proportionately to rainfall
    – Bristlecone growth responds proportionately to the ratio of sunny/cloudy days
    – Bristlecone growth responds the best to which single or combination of the above factors
    – Bristlecone growth responds the worst to which single or combination of the above factors

    I’m sure there are loads of literature on tree ring growth response to such environmental factors in general, but that doesn’t necessarily correlate to this particular tree. Given this tree is protected, difficult to culture and has a long path to maturity I wonder if it such an experiment has been done?

    It seems to me that the basic question of what climatic influence a Bristlecone tree ring is the best proxy for should be established in a controlled setting, and since I haven’t seen anything mentioned (and that may just mean I haven’t seen it) I thought it relevant to ask the question now.

  78. bender
    Posted Feb 2, 2008 at 3:18 AM | Permalink

    #78
    not to my knowledge. not for bcp.

  79. Otto
    Posted Feb 2, 2008 at 10:31 AM | Permalink

    #76 Steve: Nope. You’re missing the point entirely.

    If so I apologize. But who created Figure 2 and how? It seems that the discrepancy between Fig. 1 and 2 has to lie in the process of changing the y axis from a mean of 1 to a mean of 0.

    Steve: Otto – my point is not that there’s a discrepancy in the DATA itself. Both Figures 1 and 2 are my plots but the purpose is to illustrate the DATA problem. The Graybill chronology and the Ababneh chronology bump along quite similarly until 1840 at which point (Figure 1) the Graybill chronology surges very high. But despite this surge, the Graybill chronology post-1840 is merely a dilation of the Ababneh chronology post-1840 as shown in Figure 2. But if the two chronologies are scaled to match post 1840, the pre-1840 portions diverge. It’s not a problem that I introduced; the problem is in the inconsistent versions.

  80. Steve McIntyre
    Posted Feb 2, 2008 at 10:49 AM | Permalink

    #78, 79. There are some studies from the 1960s referenced in MM (EE 2005).

  81. pk
    Posted Feb 2, 2008 at 11:22 AM | Permalink

    Another Ababneh snippet:

    In summary, there are two important points. First, of the six groups of trees illustrated
    in Table 2, the strip-bark chronologies of Graybill and Idso 1993 differ the most in their
    tree-ring widths and therefore the whole growth pattern. Second, strip-bark tree-ring
    widths and therefore growth pattern are different from whole-bark trees. The magnitude
    of the difference between the two groups varies between the two sites. The Sheep site has
    the most pronounced increase in tree-ring widths in its strip-bark trees.

  82. deadwood
    Posted Feb 2, 2008 at 11:45 AM | Permalink

    Another possibly stupid question from a mere mortal.

    Has anyone sampled the dead trees to extend the chronology back to the MWP or Holocene Optimum?

  83. eric mcfarland
    Posted Feb 2, 2008 at 12:09 PM | Permalink

    Is everybody reading:

    http://channel.nationalgeographic.com/channel/sixdegrees/book.html

  84. deadwood
    Posted Feb 2, 2008 at 12:30 PM | Permalink

    Eric@84:

    If only models were reality, the PP would make so much sense.

    Your link is to a review of yet another “What if” science fiction tale. The purpose of CA is to audit the science, not the science fiction, of climate.

    Your insistence in playing troll for the religious side of AGW is annoying, but not convincing or converting anyone.

  85. mccall
    Posted Feb 2, 2008 at 12:39 PM | Permalink

    re: 78
    For completeness (all in one list), add

    – Bristlecone growth responds proportionately to CO2 level

  86. Posted Feb 2, 2008 at 1:13 PM | Permalink

    Re Anthony #78, and mccall #86, I would guess that all these factors affect growth, but in a nonlinear fashion. If growth were linearly affected by temperature, for example, the Amazonian BCPs would be the size of giant sequoyas. But in fact they grow so slowly that other faster growing species would crowd them out there, so we generally don’t see any at all except in harsh climates where they have a comparative advantage.

    To your list, I would add sunshine per se (even aside from cloud cover). If a Tambora screens some of the sunlight, that should stunt photosynthesis, even aside from its indirect temperature effect. But since vulcanism is responsible for some of observed decadal temperature change, it might be hard to separate the two effects when calibrating treerings to temperature.

  87. Steve McIntyre
    Posted Feb 2, 2008 at 2:15 PM | Permalink

    Folks, the issue in this thread is the inconsistency between two University of Arizona versions. This has nothing to do with whether bristlecone chronologies mean anything for temperature or precipitation proxies, as interesting an inssue as that is. The issue here is a narrower one – the inconsistency of two Arizona versions, the failure of Hughes and other dendros to reconcile the problem and the withholding of data which would permit third parties to examine the problem, even after results had been published in “peer reviewed” literature.

  88. pk
    Posted Feb 2, 2008 at 2:33 PM | Permalink

    I agree the data should be made available, but the inconsistency is explained in Ababneh’s dissertation.

    The difference between the two versions are 1) the difference between strip-bark vs. whole bark trees and 2) the difference in sample size. Graybill included what 7 to 9 strip-bark trees? The data that you’ve plotted above includes the aggregate of 25 whole-bark trees and 25 strip-bark trees from Patriarch Grove and 25 whole-bark plus 25 strip-bark trees from Sheep Mountain.

  89. Steve McIntyre
    Posted Feb 2, 2008 at 3:53 PM | Permalink

    #89. Maybe the explanation’s accurate; maybe it isn’t. That’s one factor, but maybe the calculations are done differently as well. Jeez, this is climate science. You can’t just accept this sort of thing at face value. People say things all the time. It doesn’t make the statements true.

  90. pk
    Posted Feb 2, 2008 at 4:46 PM | Permalink

    #90. I agree completely that we shouldn’t be expected to accept these things at face value. The raw data needs to be made available. I also understand the reluctance to believe anything coming from climate “science”. I’ve gone through some recent business experiences with my business partner that make me reluctant to believe anything anyone says.

    But this is a case of Occam’s Razor for me. If you look at Ababneh’s dissertation, she shows the difference between the strip-bark and whole-bark trees for both Patriarch Grove and Sheep Mountain. The Sheep Mountain strip-bark trees look quite like the Graybill series above (as might be expected), although not quite as accentuated. She attributes that inconsistency to sample size, which I think everyone here would agree is extremely important. She, very subtly, says that wrong conclusions were made from Graybill’s series because the sample size was not large enough.

    I really don’t think it’s in how they did their calculations. The simpler answer is that it’s the trees.

    My thought is that Ababneh was walking on egg shells while preparing her dissertation. I also think that maybe, just maybe, she hasn’t been given a fair shake here.

  91. bender
    Posted Feb 2, 2008 at 10:02 PM | Permalink

    don’t let the troll lead the thread astray. the topic is a huge data inconsistency in one of the most important active ingredients in every single NON-INDEPENDENT tree ring based temperature recon. what has the troll to say about that?

  92. Ron Cram
    Posted Feb 2, 2008 at 10:08 PM | Permalink

    re: 88

    Steve,

    You write:

    The issue here is a narrower one – the inconsistency of two Arizona versions, the failure of Hughes and other dendros to reconcile the problem and the withholding of data which would permit third parties to examine the problem, even after results had been published in “peer reviewed” literature.

    I’m confused. I thought Ababneh refused to provide her data (through her attorney) because she was planning to publish in a peer-reviewed journal. Did I misunderstand? Has she already published and still refuses to provide her data?

  93. kim
    Posted Feb 2, 2008 at 11:07 PM | Permalink

    That’s a good thread there, Raven, the hockey team caught in open field for once.
    ============================================

  94. Larry Huld鮢 size=
    Posted Feb 3, 2008 at 2:02 AM | Permalink

    Has Ababneh disappeared? Has anybody had any contacts with her recently?

  95. Larry Huld鮢 size=
    Posted Feb 3, 2008 at 2:07 AM | Permalink

    I don’t understand why my name is changed in the post. When I send a post I get a message that I am not allowed to post here, but still they appear here.
    Info for all: my name is Larry Huldén

    LArry: I don’t know why you’d have posting problems. WordPress must be interpreting the é incorrectly. Try ALT-0233.

  96. D. Patterson
    Posted Feb 3, 2008 at 3:52 AM | Permalink

    #104 Larry Hulden says:
    February 3rd, 2008 at 2:02 am

    Has Ababneh disappeared? Has anybody had any contacts with her recently?

    Linah Ababneh has publicly available contact information. She has been contacted at her current academic address to ascertain whether or not she was aware that Mr. McIntyre had attempted to communicate with her about her thesis. She indicated that she had received his communication, refuses to respond on advice of her lawyer, and expressed her complaint that it was improper (without indicating what the “it” was supposed to represent but seeming to mean the attempt/s to communicate with her about the thesis). In any case, Linah Ababneh has explicitly refused to respond to communications inquiring about her thesis, while indicating such communications are unwelcome. Until such time as Linah Abaneh and/or her colleagues choose to reveal more information about her thesis and/or her curious reactions towards attempts to communicate with her about the thesis, no further information about her thesis is apparently available to this commuity of readers from her.

  97. Anthony Watts
    Posted Feb 3, 2008 at 9:17 AM | Permalink

    Regarding 78,79,86,88

    I realize this is OT, and I apologize, but I thought I should add this for completeness. One of the commenters on my blog offered this.

    “Liebig’s law of minimum” It states that the growth of plants is not limited by the total sum of resources, but by the scarcest resource. Liebig’s Law states that growth only occurs at the rate permitted by the most limiting.

    http://en.wikipedia.org/wiki/Liebig%27s_law_of_the_minimum

    Liebig used the image of a barrel—now called “Liebig’s barrel” — to explain his law. Just as the capacity of a barrel with staves of unequal length is limited by the shortest stave, so a plant’s growth is limited by the nutrient in shortest supply.

    So in the case of BCP “treemometers”, it appears that temperature is only one factor, and that precip (probably the next largest factor) can be equally limiting (or enhancing if temperature is better suited at the time).

    Has anybody correlated 20th century BCP tree rings to the PDO (Pacific Decadal Osciallation)? This might explain some of the late divergence.

  98. Brooks Hurd
    Posted Feb 3, 2008 at 10:02 AM | Permalink

    Re: 1-6, D Patterson,

    Why would a scientist “lawyer up”?

    What could be objectionable about communicating with a scientist about his/her work?

    Is it only me, or does this issue with Linah Ababneh seem to be getting Kafkaesque.

  99. Posted Feb 3, 2008 at 11:44 AM | Permalink

    RE110, Thanks to some correspondence with Joe D’Aleo, here is a correlation that may show up in BCP records

    From the paper: Pacific and Atlantic Ocean influences on multidecadal drought frequency in the United States by Gregory J. McCabe, Michael A. Palecki, and Julio L. Betancourt

    Figures 4 and 5 are interesting. Figure 5 particularly because it indicates a quite a bit of variability in the west, including California and Colorado. Thus, my take is that BCP ring divergence may simply be a function of how much terrain near the trees sample promoted orographic lifting, and thus maybe better rainfall from prevailing westerly flow.

    Three rotated principal components explain 74% of the variance
    in 20-year moving frequencies of drought in the conterminous
    U.S. The first component is highly correlated with the PDO, and
    the second component is correlated with the AMO. These first
    two components explain nearly equal proportions of variance in
    the entire data set and, combined, explain 52% of the total
    variance. These results support previous research that has indicated
    the existence of a relation between these climate indices
    and drought variability in the U.S.

    and also:

    The inclusion of all three time
    series, the PDO, AMO, and a trending geophysical indicator like
    NH temperature, appears to be crucial in generating multiple
    regression equations that can accurately simulate the historical
    20-year patterns of drought frequency. This research indicates
    that persistence of the current positive AMO state may lead to
    continuing above normal frequencies of U.S. drought in the near
    future, with the pattern of drought modulated by the sign of the
    PDO.

    Again I don’t know much about trees and dendrochronology, but I do know a thing or two about weather and how much terrain affects rainfall here in the western US. I can show you places here in the Sierra that get far more precip in drought years than nearby stations, and the only difference is terrain enhancing the orographic lifting squeezing out what precipitable water there is.

    Maybe a little Google Earthing of the terrain (they have a terrain option now) for the BCP sites in question might shed some light on the problem.

  100. D. Patterson
    Posted Feb 3, 2008 at 12:12 PM | Permalink

    111 Brooks Hurd says:
    February 3rd, 2008 at 10:02 am

    [....]

    Why would a scientist “lawyer up”?

    What could be objectionable about communicating with a scientist about his/her work?

    [....]

    Good questions with no presently available answers from Linah Ababneh or the academics who were ostensibly responsible for her thesis and archiving of the data used to prepare and support the thesis. Another question is whether or not there are any other scientists or scientific organizations whom Linah Abaneh would regard as adequately qualified to request and receive further information and data about her thesis? Is her problem with the source/s of the requests and/or the fact of there being a request at all? We can only wonder at present what her response could be to a request from an organization/s such as the National Academy of Sciences (NAS), the IPCC, etc.

    Even more curious is why the people Mr. McIntyre contacted at the University of Arizona would have claimed they couldn’t help with the Ababneh thesis and insisted they didn’t know where she had gone? Abaneh’s current position and contact information was prominently displayed at her current university. How is that even the least bit possible or remotely credible, just to be generous in refraining from some obvious likely conclusions? Have they not yet learned how to use Google…really?

    To put it simply, the trail of bizarre circumstances leads right back to the University of Arizona, where climate reference weather observation stations are sited on asphalt parking lots baking in the desert sun and defended by a befuddled professor hiding behind the pseudonym of a ferocious cartoon rabbit. A few more props in the form of missing quarts of ice cream, ball bearings, statuettes, and iconic wood corings; and you’ll have the makings of another bizarre Hollywood psycho-thriller movie starring the usual psycho Hollywood stars. Of course, such bizarre happenings are simply par for the course with a Hollywood which hands out an Oscar to Al Gore while pretending the fiction movie, An Inconvenient Truth, is somehow supposed to be a documentary film. So, where does that path lead except down another rabbit hole in the company a a young lady named Alice? Does anyone happen to know whether or not the University of Arizona has ever been referred to by the student body with the nickname, Wonderland?

    Ababneh did have an abstract presented at the recent AGU 2007 meeting in San Francisco, regarding the monitoring of vegetation in Alpine meadows. Perhaps someone will someday have an opportunity to speak with her on a more collegial and fiendly basis at an AGU or other meeting.

  101. D. Patterson
    Posted Feb 3, 2008 at 12:49 PM | Permalink

    112 Anthony Watts says:

    February 3rd, 2008 at 11:44

    The important fact to remember about a bristlecone pine forest is that a much greater amount of moisture is obtained from fog drip than is received from rainfall and snowfall. A plant may obtain around 63 percent of its moisture from fog drip and 37 percent of its moisture from rainfall and snow. Orographic lifting which produces a condensing atmosphere at the altitudes of the plants are critical for bristlecone pine growth.

  102. Anthony Watts
    Posted Feb 3, 2008 at 2:04 PM | Permalink

    RE102, D. Patterson,

    Thanks, I did not know that, but fog is still a result of condensation, and subject to increased frequency on a mountain slope (orographic lifting). Again its about placement. A tree on the western windward side would do better in a drought than one further east.

  103. Peter D. Tillman
    Posted Feb 3, 2008 at 2:09 PM | Permalink

    Re Hulden, Patterson, Ababneh

    Here’s the cross-ref to the earlier discussions:

    http://www.climateaudit.org/?p=2371 #51, et seq. #58 xrefs to an earlier disc.

    Has anyone written her advisor at UA? Who was it? Maybe that’s the tack to take??

    Happy reading–
    Pete Tillman

  104. Posted Feb 3, 2008 at 2:21 PM | Permalink

    D. Patterson, #97:

    A textbook example of obscurantism.

    http://en.wikipedia.org/wiki/Obscurantism

  105. Bernie
    Posted Feb 3, 2008 at 3:59 PM | Permalink

    D. Patterson #102
    How does dew enter into the equation?

  106. D. Patterson
    Posted Feb 3, 2008 at 4:22 PM | Permalink

    #106 Bernie says:

    February 3rd, 2008 at 3:59 pm
    D. Patterson #102
    How does dew enter into the equation?

    I didn’t understand your question about the equation. Some commenters erroneously assume that the measured precipitation amounts are typically the only meaningful sources of moisture/water for the growth of bristlecone pine, foxtail pine, and other plants used as proxies for various measurements and data sources. Such an assumption is false in the Western United States, where evopotranspiration assumptions and equations are not applicable to the plant habits and ecologies found in major habitats of the Western United States. Fog drip is such an important source of water for many of the plant communities in the West, the removal, loss, and absence of certain brush and tree communities serving as fog drip collectors can cause a habitat to quickly dry up and become perpetually dominated by a dry grassland community. Anyone who might use precipitation records as the principal source of data about moisture available for plant growth must result in false conclusions. Proxy records failing to factor in fog drip as major influence upon the growth of proxies must also be in commensurate error.

  107. Posted Feb 3, 2008 at 5:48 PM | Permalink

    If anyone is interested, I found a paper studying ENSO, solar. and tree rings in Brazil.

    A STUDY OF SOLAR-ENSO CORRELATION WITH SOUTHERN BRAZIL TREE RING INDEX
    N. R. Rigozo, D. J. R. Nordemann, L. E. A. Vieira and E. Echer
    Instituto Nacional de Pesquisas Espaciais

    They claim a 76% of the variance in tree ring index was explained by solar activity and ENSO

  108. jeez
    Posted Feb 3, 2008 at 6:16 PM | Permalink

    Anthony, you’re not asking me for anything are you? Southern Brazil is very far from Rio.

  109. Craig Loehle
    Posted Feb 4, 2008 at 11:54 AM | Permalink

    Re: the actual data–what would be interesting would be to see if any of the trees showing high rapid growth in Graybill’s archive became strip barked a long time ago vs more recently, which would argue for some data processing problem or for a microsite difference.

    Re: lawyering up. This is the weirdest thing I have ever heard of. Even if you don’t get contacted by CA, your work is going to get comments on it when others publish their work and reference yours (or it will be ignored, which is even worse). You can’t lawyer up then.

  110. LadyGray
    Posted Feb 4, 2008 at 3:14 PM | Permalink

    Perhaps someone will someday have an opportunity to speak with her on a more collegial and fiendly basis at an AGU or other meeting.

    Hmmm. Was this a Freudian slip? Or are we all to be slapped with restraining orders from trying to contact her, on any basis?

  111. LadyGray
    Posted Feb 4, 2008 at 3:23 PM | Permalink

    Does anyone happen to know whether or not the University of Arizona has ever been referred to by the student body with the nickname, Wonderland?

    Funny that you should ask . . .

    Hansen, J., R. Ruedy, A. Lacis, G. Russell, Mki. Sato, J. Lerner, D. Rind, and P. Stone, 1997: Wonderland climate model. J. Geophys. Res., 102, 6823-6830, doi:10.1029/96JD03435

  112. Sam Urbinto
    Posted Feb 4, 2008 at 4:32 PM | Permalink

    So, the issues:

    1. The two are different but supposed to be the same.
    2. The data, to find out why they are different (what’s wrong), is being witheld.
    3. Peer-review doesn’t mean correct.

  113. Anthony Watts
    Posted Feb 4, 2008 at 8:15 PM | Permalink

    Seems to me, that if the Ababneh data was acquired with NSF grants or other public state or federal monies, then it would be subject to FOIA. Why not probe the funding source for the research to find out?

  114. Posted Feb 4, 2008 at 8:35 PM | Permalink

    D. Patterson (#101) wrote,

    Is her problem with the source/s of the requests and/or the fact of there being a request at all? We can only wonder at present what her response could be to a request from an organization/s such as the National Academy of Sciences (NAS), the IPCC, etc.

    I don’t know whether he flashed his badge or not, but Steve is in fact one of the 624 official Reviewers of IPCC4 WGI. (As are Ross McKitrick, William Kininmonth, and John Christy.)

  115. Michael Smith
    Posted Feb 5, 2008 at 8:08 AM | Permalink

    So, where does that path lead except down another rabbit hole in the company a a young lady named Alice?

    The more I read about AGW issues, the more I ask myself, “Why, oh, why didn’t I take the BLUE pill?”

  116. Steve McIntyre
    Posted Feb 5, 2008 at 2:36 PM | Permalink

    Look, there’s no magic request place. FOI only works if the agency has the data. If the agency never bothers getting the data, they can deny the request. Agencies also provide mendacious replies from time to time. We FOI’ed NOAA for any IPCC Review Comments in the possession of NOAA employees (e.g. NOAA employee WG1 Chairman Susan Solomon). They denied having any Review Comments in their possession. The situation became moot when IPCC then provided the comments online, but NOAA itself was unresponsive.

    NAS published Lonnie Thompson and then refused to ask him to provide data despite policies. NSF has refused to get data from Thompson or Mann etc – why would they ask Ababneh?

    I asked Cicerone of NAS to simply ask various authors to provide data – not as a demand, simply as a request from someone eminent. He refused.

    I asked Gerry North. North said that he asked everyone on my list (Thompson, Mann,…) for specific data. I presume that no one gave him any since I never heard back.

    I haven’t overlooked any obvious avenues. If I can’t get at Thompson’s Dunde data which was collected in 1987, why is Ababneh data going to be any easier?

  117. Bernie
    Posted Feb 5, 2008 at 8:01 PM | Permalink

    #107 D Patterson
    The equation was metaphorical. If fog drip is a significant source of moisture in these areas, relatively speaking how significant
    is dew? I am assuming that it would be more frequent but less volume per incident. How much variation is there likely to be in this compnent of the total amount of moisture?

  118. D. Patterson
    Posted Feb 5, 2008 at 9:29 PM | Permalink

    118 Bernie says:

    February 5th, 2008 at 8:01 pm
    #107 D Patterson
    The equation was metaphorical. If fog drip is a significant source of moisture in these areas, relatively speaking how significant
    is dew? I am assuming that it would be more frequent but less volume per incident. How much variation is there likely to be in this compnent of the total amount of moisture?

    The one-third precipitation and two-thirds fog drip–dew ratio for various plant communities in the dry season appears to be a commonly described ratio in science literature discussing sources of moisture in circumstances of restricted precipitation and highly variable precipitation. How much of the fog drip, rime ice, and other ice moisture represents dew formation from clouds and mist and how much from clear air is not clear to me, but I would make an educated guess the fog mist is the substantially greater contributor by quantity. How much a given form of such moisture is contributed to individual plants and sites is likely to be highly variable. A one hundred meter square plot of ground can host multiple climate zones within such a microsite due to the plants present, slope angle and spatial orientation, soil and rock characteristics, wind exposures, and more. There are probably one or more theses-dissertations which very much need to be published which will provide some accurate measurements of the microsite cultural conditions for the plant communities being used as proxies for other measurements.

  119. SteveSadlov
    Posted Mar 13, 2008 at 1:07 PM | Permalink

    Bump.

  120. Tony
    Posted Jul 3, 2008 at 2:07 PM | Permalink

    Steve, can you please confirm:
    You are trying to access:

    http://www.ltrr.arizona.edu/

    And NOT

    http://ltrr.arizona.edu/

    ?

    Because I get a time-out for the second URL.

    And could you please tell us what kind of error you get (time-out, 403, etc.)?

    Steve: They seem to have lifted the block; I can go there now. :) Sunshine helps. But it was real enough a little while ago.

  121. Mike Rankin
    Posted Jul 3, 2008 at 2:51 PM | Permalink

    The first url reaches the Arizona tree ring site for me.

  122. Posted Sep 2, 2008 at 10:37 AM | Permalink

    I’m confused. I thought Ababneh refused to provide her data (through her attorney) because she was planning to publish in a peer-reviewed journal. Did I misunderstand? Has she already published and still refuses to provide her data?

    Steve: The discussion was between Ababneh and a CA reader; Ababneh said that the refusal was on legal advice, but the answer was provided directly and not through an attorney. The reconstruction appears in an article on archaeological sites, but this is passim. The chapter of her thesis containing the analysis relative to Graybill has not been published in a journal. The terms of her thesis said that the data would b archived, but the university has taken no steps to require that the data be archived and, as noted elsewhere, Hughes made no mention of this data in his AGU 2007 presentation on bristlecones.

2 Trackbacks

  1. [...] in 2003: see Ababneh 2006 (Ph. D. Thesis), 2007 (Quat Int). However, as previously reported at CA here (and related posts), Ababneh failed to replicate the distinctive HS shape of Graybill’s Sheep [...]

  2. By Tamino and the Magic Flute « Climate Audit on Mar 22, 2012 at 5:06 PM

    [...] in 2003: see Ababneh 2006 (Ph. D. Thesis), 2007 (Quat Int). However, as previously reported at CA here (and related posts), Ababneh failed to replicate the distinctive HS shape of Graybill’s Sheep [...]

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