PAGES2K vs the Hanhijarvi Reconstruction

The PAGES2K (2013) Arctic reconstruction of Kaufman et al has attracted considerable attention as a non-Mannian hockey stick. However, it’s been fraught with problems since day one, including a major re-statement of results in August 2014 (McKay and Kaufman, 2014 pdf), in which Kaufman conceded (without direct acknowledgement) Climate Audit criticism that their results had been impacted by the use of contaminated data and upside-down data.  But there’s a lot more.

In March 2013, almost exactly contemporaneous with PAGES2K, Hanhijarvi et al, pdf here, the originators of the paico method, published their own Arctic reconstruction, which has undeservedly received almost no publicity.   (In this post, I will use “PAGES2K” to refer to the PAGES2K Arctic reconstruction; the full PAGES2K study includes other areas, including Gergis’ Australian reconstruction.)   But unlike PAGES2K, its medieval reconstruction has higher values than its modern reconstruction – a finding that has received negligible coverage.  Because its methodology matches the PAGES2K methodology, the difference necessarily arises from proxies, not from method.

Nor is the issue merely “regional” coverage though Hanhijarvi et al’s Arctic reconstruction is based on North Atlantic proxies though it would be puzzling even as a “regional” result.  These proxies from a very large subset of the PAGES2K Arctic data (27 of 59 series, using no other data).  With such a large subset, one can only obtain the PAGES2K Arctic results if there is a superstick for the rest of the data (non-H13 proxies).  As a regional result, specialists would have to explain the physics of a medieval warm period in the North Atlantic concurrent with extreme cold in the rest of the Arctic, if one were to take these results at face value.

But before attempting such a complicated solution,  it is important to note that Kaufman’s proxies are fraught with defects. Kaufman has already acknowledged that one of his supersticks (Igaliku) was contaminated by modern agriculture; and that another non-H13 series (Hvitarvatn) was used upside down. Several series, thought to be temperature proxies as recently as 2013, were removed in August as no longer “temperature proxies”.  For inexplicable reasons, Kaufman failed to remove all the contamination from the Igaliku series and his inversion of the Hvitarvatn points to major inconsistencies with other series.  Further, although Kaufman has acknowledged multiple errors in the PAGES2K Arctic reconstruction, he has not issued a corrigendum, thereby permitting the erroneous series to continue in circulation, while, oddly, thus far not providing a digital version of the amended reconstruction.

The Paico Reconstructions

First, here are the H13 (blue) and PAGES-2013 (black) reconstructions, overplotted on the New York Times version of Kaufman et al 2009 (see Andy Revkin here).  The PAGES-2013 reconstruction was similar in shape to the Kaufman-2009 reconstruction, but had nearly double the amplitude. Its medieval period was much cooler than the late 20th century -indeed, it was about the same temperature as the Little Ice Age of Kaufman et al, only a few years earlier.  While the wiggles of the H13 reconstruction have much in common with the wiggles of PAGES-2013, the net result is completely different:its medieval warm period is over 1 degree warmer than PAGES-2013 and warmer than the 20th century portion of the reconstruction. Once again, given that the method is identical and that the H13 data is a very large subset of the PAGES-2013 data, the difference is really quite extraordinary.



Figure 1. Kaufman et al 2009 reconstruction from New York Times, overplotted by H13 reconstruction.  40-year gaussian smooth. Both centered to 1961-1990 reference. 


PAGES2K Figure S3a

None of the PAGES2K graphics are very clear. The clearest depiction of their arctic reconstruction is their Figure S3a, which, however, is in standard deviation units.  In the diagram below, I’ve plotted smoothed versions of the PAGES-2013 (yellow) and H13 reconstructions (red), both in SD units for consistency. Unlike the previous diagram where the series are aligned at the closing reference period (1961-1990) and diverge in earlier periods, when plotted in this perspective, the divergence occurs in the HS-blade at the end. This information is identical to the previous plot, but the perspective is different. In this perspective, the difference seems to arise from the amplitude of the blade.


arctic_paico_with_hanhiharviFigure 2. PAGES2K (2013) Figure S3a overplotted by smoothed PAGES2K reconstruction (yellow) and Hanhijarvi et al 2013 reconstruction (red). Gaussian 50-year smooth.


PAGES2K Corrections

The PAGES2K non-corrigendum corrigendum did not show a direct comparison of their new reconstruction to the 2013 version, but did show the corrections in Figure 2 as shown below. I’ve overplotted the difference between the H13 and PAGES-2013 reconstructions (in blue), showing that the corrections have already gone about halfway towards H13.  Unfortunately, Kaufman did not archive the new version. I’ve written to Nature asking them to require Kaufman to archive the results, but they instead told me to get the results from the authors. I argued that the corrected results should be available officially and not merely in a grey version. I’ll see how this goes.

Given the size of the changes arising from corrections to date, it will be interesting to see what happens when contamination in the Igaliku is fully removed (the incomplete removal being unacceptable) and when the orientation of the Big Round Lake series matched the corrected Hitarvatn series.


Figure 3. Differences to PAGES-2013 version. Black – PAGES-2014; blue- Hanhijarvi et al 2013.


My 2006 AGU Union Presentation

As one further comparison, the next figure compares the Hanhijarvi reconstruction to a figure in McIntyre 2006,  The Impact of NRC Recommendations on Climate Reconstructions, a presentation to the 2006 AGU Union session. I present this example, in part, as one further rebuttal of Nick Stokes’ fabricated claim that I have supposedly been reluctant to show the effect of criticisms on proxy reconstructions or that such graphics are in any way “inconvenient”. One of the original themes of Climate Audit has been that the canonical reconstructions relied on small networks and that the same data was used over and over again, and that slight and plausible changes in proxy selection, replacing bristlecones and/or Yamal with equally or more plausible proxies led to very different looking reconstructions. To support this assertion, the closing slide in my presentation showed the effect of slight changes in proxy networks on several canonical reconstructions (Mann, Jones, Esper, Moberg.)   Presentation of this figure caused Hughes to splutter in rage, claiming that this was one of the most despicable things that he had ever seen at a scientific conference. I’ve overplotted the H13 reconstruction on this figure, showing that it is, if anything, an even more extreme example of the variations in my 2006 presentation. agu06_with_hanhijarvi

Figure 4. Hanhijarvi reconstruction (black) plotted on figure from McIntyre 2006, The Impacts of NAS Recommendations on Reconstructions, AGU Union Session, 2006.  For each reconstruction, I had made plausible variations in proxy selection, yielding different long-term appearance, but relatively similar modern “verification”.  The Hanhijarvi reconstruction has a similar pattern but greater amplitude.


The Proxy Networks

I’ve already observed that the H13 network is a very large subset of the PAGES2K network (27 of 59 proxies.)

By Region

H13 focused on North Atlantic and northern Europe. Between 45 west (in Greenland) and 30.5 east (Finland), PAGES2K used 29 proxies, 27 of which were in the H13 network. The only additional PAGES2K proxies were Hvitarvatn – which Kaufman used upside down; and a Finnish chironomid series (Pieni-Kauro) that did not reach back to the MWP.

PAGES2K used on only five series east of 31 east, only three of which reached the MWP. All three are familiar to CA readers: the Yamal superstick of Briffa 2008 (since downsized in Briffa et al 2013); Avam-Taimyr of Briffa 2008 and Esper’s Polar Urals. None of these break new ground obviously.

25 series come from west of 45 west. There are 16 lake sediment series, many of which have been discussed, mostly critically at CA; there are 4 D’Arrigo tree ring series and 5 ice core series from western Greenland and the Canadian archipelago.

By Proxy Type

Ice core O18:  Both H13 and PAGES2K contain substantial subsets of ice core O18, an important  proxy class without a material HS.  H13 uses 11 of 16 PAGES2K ice core series (Dye3, Renland, Crete, GISP2, GRIP, B16, NGRIP1, B18, Lomonosovfonna, B21 and Austfonna); the five additions in PAGES2K are from west Greenland and the Canadian islands:  Camp Century, Agassiz, Devon, Penny (O18 and melt).  None of these five are material to the HS.  H13 used the longer Lomonosovfonna version, adopted in the 2014 PAGES non-corrigendum.

Ocean:  All six ocean cores used in PAGES2K are used in H13: P1003, MD99-2275_diatom, MD99-2275_alkenone, MD95-2011_diatom, MD95-2011_alkenone and MSM5_5-712.

Speleothem:  the only PAGES2K speleothem (Okshola) is used in H13.

Documentary: the only PAGES2K documentary series (Bergthorsson Iceland sea ice) is used in H13.

Tree rings:  H13 used four tree ring series out of 13 PAGES series: Jamtland, Tornetrask (Grudd), Forfjorddalen-2,  Finnish Lapland. PAGES2K added nine series, five from Siberia (Briffa’s Avam-Taimyr and Yamal series; Esper’s Polar Urals series and two other series :Indigirka STD, Lower Lena ARS) and four Jacoby/D’Arrigo series from North America (Seward Peninsula, Gulf of Alaska, Yukon and Coppermine series).   PAGES2K-2014 changed to Briffa’s Tornetrask version in 2014.

Varved lake sediments:  H13 used 2 Finnish varve series (Korttajarvi, Lehmilampi) in which modern contamination had been removed. PAGES2K added one Iceland series (Hvitarvatn) and five North American series  (Blue Lake, Lower Murray, C2, Hvitarvatn, Iceberg, Donard and Big Round), all of which had been previously used in Kaufman et al 2009 and repeatedly used thereafter in recent multiproxy studies e.g. Ljungqvist.  The Kaufman series are all problematic.

Chironomids: H13 used one chironomid series (Hamptrask from Luoto); PAGES2K added another Luoto series from Finland and four series from North America (Moose, Hudson, Screaming Lynx and Lake 4). All are low resolution and none look like they would tip the calculation from H13 results to PAGES2K results.

Other lake sediments:  PAGES2K also used seven singleton lake sediment series (“singletons” are proxies that only occur once in the network).  I think that multiproxy studies should avoid singletons in favor of proxies with enough population to see what might be going on. H13 included one of these series (the truncated Nautajarvi series). Three of the six PAGES2K singletons were withdrawn in PAGES-2014 as no longer “temperature sensitive”: Kepler, Alaska (O18); East Lake, Melville Island (particle size),  Holsteinborg, Greenland (Fragilariopsis cylindrus).  The closing dates of another series (Lone Spruce, Alaska) were amended by 50 years in PAGES-2014.   The Igaliku, Greenland (pollen accumulation) series is severely contaminated by modern agriculture and has a huge non-climatic HS. PAGES-2014 acknowledged the contamination, but only removed the contaminated portion after 1970, leaving prior contamination (enormous) still in the network.  The other singleton is the Braya So (alkenone) series.


First, a little backstory, then some discussion.

Hanhijarvi’s background appears to be mathematics, rather than birds and bees and forests, and his publications include actual mathematics. His two coauthors were Martin Tingley, a young Canadian statistician now active in paleoclimate,  and Atte Korhola, a prominent Finnish paleolimnologist, both of whom have been mentioned at CA.

Tingley was praised by David Appell in 2009 for the hockey-stickness of his reconstruction with Peter Huybers (then in draft).  They(presumably inadvertently) used Mann’s version of the contaminated Korttajarvi sediments – upside-down as well.  Although the problem had been well publicized at Climate Audit, Mann’s failure to issue a corrigendum left this contaminated series still in play. In October 2009, a few weeks before Climategate, I criticized their use of Mann’s contaminated data.  Their 2009 draft article was not published until 2013. The final article, Tingley and Huybers 2013, still used Mann’s contaminated data, an unwise decision that detracted from the significance of their particular HS. I was very critical of this carelessness in my CA comment at the time.

In the same month (October 2009) that Tingley’s use of upside-down Tiljander was first publicized here, the third coauthor, Atte Korhola, severely criticized Mann’s use of contaminated data, using language and terms that Steyn could directly quote in court (below is Jean S’ translation):

the Proxies have been included selectively, they have been digested, manipulated, filtered, and combined, for example, data collected from Finland in the past by my own colleagues has even been turned upside down such that the warm periods become cold and vice versa. Normally, this would be considered as a scientific forgery, which has serious consequences.

Korhola’s involvement in the present project is salutary as Korhola, unlike Tingley’s coauthor in Tingley and Huybers, is familiar enough with the data to know when it is pointing up or pointing down and not to use data that has been agriculturally contaminated.  Keeping proxies in the correct orientation seems little to ask of multiproxy authors, but it seems to be an almost insuperable challenge for many supposed specialists.

I’m not presently in a position to comment on technical merits of paico other than briefly. I haven’t handled the code. (I don’t have any present plans to try to translate from Matlab into R and the authors have thus far only made the package available in Matlab – no complaint on that in terms of documentation, but it does restrict usability for people who speak R.)  Like most CPS algorithms, paico presumes that the orientation of each proxy is known ex ante – a protocol that has long been advocated at Climate Audit. This avoids flipping, as can happen in some multivariate methods (including principal components).  It also avoids the many scaling and rescaling operations that litter most proxy reconstruction methods:  such rescaling is assumed by practitioner to be cost-free, but this is not necessarily the case (but this is outside the scope of today’s post).

I’ve now written a number of posts on PAGES2K (see tag).  I had noticed almost immediately after publication that they had used a sediment series with a huge HS due to recent agricultural contamination (Igaliku) – an error eerily similar to Mann’s upside-down Tiljander.  In addition, I reported that another of the major contributors to their HS (the Hvitarvatn, Iceland varves) had been used upside-down (also here) and that PAGES2K had inexplicably used a short version of the Lomonosovfonna, Svalbard ice core, even though one of the PAGES2K coauthors had earlier data with a higher MWP.   I criticized PAGES’ post hoc exclusion of the Mount Logan ice core O18 series because it went the “wrong way” due to “regional” fluctuations, while keeping the upticked Austfonna series, the uptick of which could just easily be “regional”.  I later observed that PAGES’ Kepler lake sediment O18 series was similar to the Mount Logan ice core series and that it was impossible to explain the exclusion of one and not the other (I disagreed with ex post exclusion of Mount Logan).  Late last year, I wrote a lengthy review of Kaufman’s  varve thickness series that have become common to nearly all recent reconstructions, though even the orientation of these series is sufficiently unclear to confuse specialists and lead to contradictions.

All of these criticisms were adopted in the PAGES-2014 non-corrigendum without specific acknowledgement. Part (but not all) of the Igaliku contamination was removed; the Hvitarvatn series was inverted; the longer Lomonosovfonna series was deployed. Rather than include Mount Logan, they removed Kepler.  In addition, they removed the early portion of several tree ring series (Coppermine, Lower Lena, Forfjorddalen) where there were insufficient cores (incorrectly explaining the change as “restricted to temperature sensitive section”) and replaced a couple of tree ring series with different versions (replacing a Swedish version of Tornetrask with a more HS-shaped version from the University of East Anglia and another in Alaska).

Although the above errors warrant a corrigendum, Kaufman did not post a corrigendum at the PAGES2K, here apparently adopting Mann’s technique of not reporting corrigenda at the original article (thereby permitting continued use of the impacted results), but quietly disclosing the errors in a different location as CYA.

In my initial response to the non-corrigendum corrigendum, I observed that there were other shoes that might still drop:  Kaufman only removed post-1970 contamination from the Igaliku record, which remains seriously contaminated in the mid-20th century. Some of Kaufman’s other series remain very problematic: the Big Round varve series has extraordinary similarity to the Hvitatvatn series, but they are now in opposite orientation. Other Kaufman muds are a mess: in the amendments, Kaufman removed the early portion of the Blue Lake, Alaska series as not being “temperature sensitive”, but the removal seems completely ad hoc and post hoc; meanwhile, other series with clearly identified inhomogeneities e.g. Iceberg Lake (but HS contributors) are left untouched.



The very large differences between H13 and PAGES2K Arctic arise not from methodology, but from proxy selection, with the diagnosis being sharpened by the fact that H13 is an exact subset of PAGES2K.  It would be very interesting to a paico run on the non-H13 subset of PAGES2K – does it have an even more pronounced superstick? This sort of inconsistency between proxies with a medieval warm period and HS-shaped proxies is, of course, familiar to CA readers.

In addition, there are still important remaining issues in the PAGES2K, including unremoved contamination in the Igaliku superstick and the puzzling mirror orientation of Hvitatvan and Big Round.  Such changes would take PAGES2K even further to the direction of Hanhijarvi et al.



A few days ago, Jean S extracted their reconstruction, which I’ve overplotted on their Figure 7 to prove the match. If you squint,  you can see the dotted black line (digital) overplotting the blue H13 reconstruction. The H13 reconstruction goes from 0 to 2000. H13 Figure 7 showed decadal averages for 0-9 years. The closing uptick in the graphic comes from the single 2000 value. Any other smoothing yields a closing value that is not only below the medieval values, but the 1930s values. The other series in the spaghetti graph are Mann et al 2008 (CPS and EIV), Moberg and Kaufman et al 2009 (red).

Figure A1. Hanhijarvi et al 2013 Figure 7.  Calculated reconstruction plotted in blue over the figure, showing very close match with plot of Hanhijarvi reconstruction shown in the figure.


Hanhijarvi et al,, 2013 (Clim Dyn.) Pairwise comparisons to reconstruct mean temperature in the Arctic Atlantic Region over the last 2,000 years.

McKay and Kaufman, 2014 (Scientific Data).  An extended Arctic proxy temperature database for the past 2,000 years

PAGES2K Consortium, 2013 (Nature), Continental-scale temperature variability during the past two millennia.


  1. Pethefin
    Posted Oct 8, 2014 at 1:23 AM | Permalink

    Spelling mistake in the headline, it should read Hanhijarvi (actually Hanhijärvi) as it does in the text.

    Jean S: Kiitos, corrected.

    • barn E. rubble
      Posted Oct 8, 2014 at 10:39 AM | Permalink

      RE: Jean S: “Kiitos, corrected.”

      For those wondering, kiitos = thank you. One of the few bits of Finnish I can still recall . . . sigh . . . among other things.


      *anglicized from baärn Ee. ruuble

  2. Skiphil
    Posted Oct 8, 2014 at 2:20 AM | Permalink

    link missing, under “The Paico Reconstructions”

    the phrase, “overplotted on the New York Times version of Kaufman et al 2009 (see Andy Revkin here)” seems to need a hyperlink at “here”

    referring to this article/graphic:

  3. Jean S
    Posted Oct 8, 2014 at 2:48 AM | Permalink

    The press release of Hanhijärvi et al. here (in Finnish). Google translation is reasonably understandable (although it is also translating Hanhijärvi (=goose lake)).

    • Posted Oct 8, 2014 at 9:08 AM | Permalink

      Re: Jean S (Oct 8 02:48),

      A better Google translation than many I’ve seen, but as usual some words remain untranslated. Posting a short key to such words as well would be helpful when providing a Google translation link, particularly if, as here, some knowledge of Finnish grammar is needed to look up mutated word forms even when a dictionary is to hand, which itself is not very likely. Here’s my version, with one uncertainty for clarification:

      merijääpeitteen sea ice cover
      viilenemiskehityksen framework of cooling Jean S: the cooling trend/development
      “saneet boost” “have got a boost”? (should this be saaneet?) Jean S: Yes.
      mannerjäätiköihin mainland glaciers Jean S: ice sheet?
      kalkkikiviluolien limestone cave
      vertailupareihin pairwise comparison

      • Sven
        Posted Oct 8, 2014 at 9:25 AM | Permalink

        OK, found now, where the “saneet boost” came from. In the finnish text it’s “saneet lisäpotkua” (a typo, should be “saaneet”) and this really is “have got an additional boost”.

      • Jeff Alberts
        Posted Oct 8, 2014 at 9:37 AM | Permalink

        Does the universe implode if you translate Finnish to Welsh?

        • Sven
          Posted Oct 8, 2014 at 9:44 AM | Permalink

          Probably. But it’s physics, so, to be really sure, you should ask ATTP.

        • Posted Oct 8, 2014 at 10:33 AM | Permalink

          Kenneth Pike told me quantum physics might unlock the deep problems of linguistics the one time we talked. But Dr Pike’s passed on and we can be confident, as you say, that ATTP will show us the way.

      • Posted Oct 8, 2014 at 10:35 AM | Permalink

        Re: Peter O’Neill (Oct 8 09:08),

        Kiitos Jean

        I was amused as a foreigner to spot a spelling error. Perhaps I should apply for a proofreading job!

        I suggested glaciers here rather than ice-sheets since both are mentioned only in the references for the actual article, and ice sheets there in the context of “A ‘triple sea-ice state’ mechanism for the abrupt warming and synchronous ice sheet collapses during Heinrich events”, while glaciers appear in the context of “Deep drilling of glaciers in Eurasian Arctic as a source of paleoclimatic records”

        Cooling trend does read better than framework of cooling. sisällä/within had me looking for a word to put something “within”.

        Jeff Alberts: As for universe implosion on translation of Finnish to Welsh, I think this is avoided provided you make an intermediate translation to Irish.

        • barn E. rubble
          Posted Oct 8, 2014 at 10:48 AM | Permalink

          RE: Re: Peter O’Neill (Oct 8 09:08),
          RE: “Jeff Alberts: As for universe implosion on translation of Finnish to Welsh, I think this is avoided provided you make an intermediate translation to Irish.”

          Short answer: no. My Father was from Finland and me Ma from Ireland. Most translations from Finnish to Irish (as me Ma was want to do) would result in explosions (of one sort or another). They met in Toronto in the 50’s, and according to Da neither could speak English when they got here . . . sigh . . . those were the days.


        • Sven
          Posted Oct 8, 2014 at 11:19 AM | Permalink

          Yes, you are right. I started learning Irish some 25 years ago and tried some translation from Estonian (very close to Finnish) to Irish. The result was not an implosion but rather an explosion. A small one, not catastrophic. So, to be on the safe side, using Irish as a dampener would be a wise thing to do.

        • Posted Oct 8, 2014 at 12:39 PM | Permalink

          Re: Peter O’Neill (Oct 8 10:35),

          Thinking about it more carefully, ice-sheets probably is the better choice where qualified, as here, by “mainland”

          But, least my original point gets lost, that was that is always helpful when posting a Google translate link to add a key to the words which remain untranslated.

  4. Skiphil
    Posted Oct 8, 2014 at 5:08 AM | Permalink

    OT: see #26 on Gergis pub. list, re: Gergis, et al. for PAGES Aus2K project, still listed “in review” at Journal of Climate

    Is this long overdue work or something new?

    Jean S: The year is updated and Phipps is not anymore a co-author. I think they are still trying.

    • Posted Oct 8, 2014 at 7:25 AM | Permalink

      Very trying:)

      The pun may not translate well into Finnish!

      Of the main post, this is incredible work Steve. From:

      I’m not presently in a position to comment on technical merits of paico other than briefly. I haven’t handled the code. (I don’t have any present plans to try to translate from Matlab into R and the authors have thus far only made the package available in Matlab – no complaint on that in terms of documentation, but it does restrict usability for people who speak R.)

      I can see more of Jean S’s motivation to push Octave. But all these things take time.

    • Skiphil
      Posted Oct 8, 2014 at 3:59 PM | Permalink

      wonder what the story is with Phipps, did he ask to be taken off, were they having some conflict over the failings of the project etc.??

  5. Sven
    Posted Oct 8, 2014 at 9:19 AM | Permalink

    kehitys is actually development, but maybe in the context it could be framework?
    “saneet boost” (or even “saaneet (have gotten) boost”) is not finnish, something wrong there

    • Sven
      Posted Oct 8, 2014 at 9:20 AM | Permalink

      oops… wrong place. It was of course meant as reply to Peter O’Neill 9:08 AM

  6. Craig Loehle
    Posted Oct 8, 2014 at 9:23 AM | Permalink

    A veritable cherry pie bakery. I’m glad these guys don’t design airplanes. When the whole story is altered by how you align the curves (whole series vs recent decades) the story is infinitely malleable. That isn’t science.

    Steve: there’s nothing new here about the effect of alignment. That’s was evident in Briffa’s 1992 bodge of Tornetrask or in say Ababneh vs Graybill – they align over the whole series and diverge if matched at the end.

  7. tty
    Posted Oct 8, 2014 at 9:28 AM | Permalink

    The weirdest thing about all this Arctic Hockeystickery is that there are actually a number of long high-quality thermometer records from high latitudes in the North Atlantic area. In particular a composite from southern Greenland from 1784, a very high-quality and homogenous series from Stykkisholmur, Iceland from 1830 and a composite (but very carefully homogenized) series from Torne Valley from 1802.
    They all show rising temperatures since c. 1800, a marked high-temperature “hump” in the 1930’s, a subsequent decline and new rise, with current temperatures about equal to the 30’s. No hockeystick anywhere.
    And the same pattern is seen in the very long series from St Petersburg and Uppsala (from 1722!).

    It is also odd that everybody is so fond of the Torneträsk treering proxy, while nobody uses the Torne älv ice breakup date proxy (available since the 17th century), since the latter correlates with spring temperature at the 0.8 level for the last 200 years while the Torneträsk series correlation with summer temperatures is about 0.4 for the same interval.

    • James Evans
      Posted Oct 8, 2014 at 1:45 PM | Permalink

      Are there any pretty graphs of those thermometer records on the interwebs for an oik such as myself to take a gander at?

      • Bob Koss
        Posted Oct 8, 2014 at 3:53 PM | Permalink

        James Evans,

        I was curious also, so I graphed the Stykkisholmur data tty mentioned which I found in the ISTI databank.
        The years 1873, 1919, 1941 are missing either first or last six months of data for the year. Couldn’t find Torne Valley listed under that spelling though.
        Here it is.

      • Steve McIntyre
        Posted Oct 8, 2014 at 4:07 PM | Permalink

        please do not divert this thread into a discussion of thermometer records. These can be discussed at other venues or other threads. Thermometers have been discussed endlessly, whereas this thread raises an important new issue in connection with the reconstructions.

  8. miker613
    Posted Oct 8, 2014 at 9:36 AM | Permalink

    “But unlike PAGES2K, its medieval reconstruction has higher values than its modern reconstruction – a finding that has received negligible coverage.” Amazing. Mark Steyn, where are you? Can’t you get your Oil Money masters to publicize this? “HOCKEY STICK REFUTED!!!” That sort of thing. Faux News, are you sleeping? Heartland Institute, you’re tight with Andy Revkin – get him to cover this! What are you thinking – here’s your chance!

    • Jeff Alberts
      Posted Oct 8, 2014 at 9:40 AM | Permalink

      You forgot your /sarc. Or maybe you didn’t.

    • Steve McIntyre
      Posted Oct 8, 2014 at 10:01 AM | Permalink

      my own take these reconstructions is not that one is necessarily “right”. However, one can say that using contaminated data and using data upside down is “wrong” in some sense.

      • Sven
        Posted Oct 8, 2014 at 10:02 AM | Permalink

        “…in some sense”:)

    • miker613
      Posted Oct 8, 2014 at 10:06 AM | Permalink
      • miker613
        Posted Oct 8, 2014 at 10:07 AM | Permalink

        Well, that didn’t work. I tried to add a tin-foil-hat tag, as Jeff Alberts suggested.

  9. miker613
    Posted Oct 8, 2014 at 10:03 AM | Permalink

    Figure 2 (from S3A) is the one that I can’t get my head around. They really look the same: basically the difference is the _blade_: PAGES2K found some proxies that match current temperatures. Another Briffa divergence problem, correct? The obvious conclusion (I would think) is that temperature proxies do a really bad job. It’s not that we’ve found the Medieval Warm Period in H13; it’s that all of this is probably wrong.

  10. miker613
    Posted Oct 8, 2014 at 10:45 AM | Permalink

    From a comment at ATTP:
    ‘[PAGES2K]“One of the new procedures used to reconstruct temperature is an approach developed by Sami Hanhijärvi (U. Helsinki), which was also recently applied to the North Atlantic region… … Hanhijärvi applied this procedure to the proxy data from each of the continental-scale regions and found that reconstructions using different approaches are similar and generally support the primary conclusions of the study.”

    So this study seems to look at a subset of the northern hemisphere, and yes, when smaller regions are considered, there is more variation. Which is what everyone would expect.’


    Steve: the issue in this post is not paico versus other methods, but the difference between the PAGES2K Arctic paico and the Hanhijarvi Arctic paico (from North Atlantic), using the North Atlantic subset of PAGES2K. The differences are too big and require explanation. Thus far, we’ve some explanation: contaminated and upside down data in the non-H13 PAGES2K data. To the extent that this shows that “contaminated and upside down data” “support the primary conclusions of this study”, I guess that this is probably a true statement, though not one that is very compelling.

    • Steve McIntyre
      Posted Oct 8, 2014 at 12:27 PM | Permalink

      I’ve added some commentary in the introduction about the “regional” issue and a direct clarification that I’m comparing to PAGES2K Arctic (though I don’t think that anyone could reasonably have been confused on this.) The studies by Gergis and Neukom are garbagey, but that’s a different issue.

      The interesting issue for me was the tremendous difference between the PAGES2K Arctic and Hanhijarvi studies using identical methods and similar proxies. The differences deserve reconciliation, rather than a shrug saying its just “regional”.

      For years, specialists have purported to explain proxy inconsistency as simply “regional”, without explaining how such differences could arise in physics. How can one combine proxies that show a Little Ice Age in Baffin Island with proxies that show a concurrent “warm period” in Baffin Island and say – its just “regional”.

      If one estimates the Rest-of-Arctic temperature by difference from the results for Hanhijarvi and PAGES2K, they would be even colder than the PAGES2K-2013 results.

      • Jean S
        Posted Oct 8, 2014 at 5:12 PM | Permalink

        I think it is also worth mentioning that Kaufman et al. (2009) used 23 (IIRR) series for the whole Arctic whereas H13 is using 27 proxies for a smaller area, so the difference (between PAGES2k and H13) can not be explained away with “low sampling”. There should be enough proxies in H13 if there were in Kaufman (2009). Steve, what is the spatial distribution of those proxies that are not in H13?

        Steve: two in the H13 area (Hvitarvatn and a Luoto chironomid in Finland. Or maybe three, counting Igaliku in east Greenland, which is a lousy series on multiple counts. It even fails the stated PAGES2K resolution standard.

        Five series east of FInland from Siberia: including the Yamal superstick (old version); Avam-Taimyr; Esper’s Polar Urals and two short tree ring series.

        24 other series to the west of the H13 catchment.

        2 from west Greenland: Camp Century is typical Greenland O18, not much centennial variation in this period.

        they show 10 from Alaska and Yukon (141-162W), lake sediments, mostly published in programs edited by Kaufman, and tree rings. wait a minute, it’s nine – they have the wrong longitude for the Coppermine river.

        1 series between 141W and 84W: Coppermine River tree rings (115W not 155W). They’ve discarded East Lake.

        5 from the eastern Canadian archipelago other than Baffin Island: three from Ellesmere Island (2 sediment, 1 ice);
        a chironomid series from Southampton Island; an ice core from Devon Island.

        4 from Baffin Island (61-67W), which is affected by North Atlantic and whose history ought to cohere with Iceland and Greenland. The Big Round series that I’ve been talking about is upside down to Hvitarvatn, but otherwise they match about as well as any two sediment series can be imagined.

    • Steve McIntyre
      Posted Oct 8, 2014 at 1:43 PM | Permalink

      actually, the Arctic series has a major impact on the area-weighted PAGES result. I’ve experimented with H13 instead of PAGES13 and got a big change.

    • amac78
      Posted Oct 8, 2014 at 9:38 PM | Permalink

      > To the extent that this shows that “contaminated and upside down data” “support the primary conclusions of this study”, I guess that this is probably a true statement.


  11. Follow the Money
    Posted Oct 8, 2014 at 5:04 PM | Permalink

    H13 used 2 Finnish varve series (Korttajarvi, Lehmilampi) in which modern contamination had been removed.

    The PAGES2k (2014) update adopted those cropped extents, plus the one for Nautajarvi, from H13 (ie, pages proxies 14, 26, 31; H13 proxies 25, 26, 27.

    I do not see H13’s proxy 9, Longyearbyen ice core [Divine et al. (2011)] in the PAGES2k data.

    H13 proxies 13 and 14 are diatoms and alkenones from site MD99-2275. These differ in that their year extents flip, H13 13 diatoms “-2,549-2000” are the extent dates for PAGES Arc_57 MD99-2275’s alkenones. And vice versa.

    H13 proxies 15 and 16 are diatoms and alkenones from site MD95-2011. These differ in that they flip just like 13 and 14. The extent of H13 15 diatoms is “-6,540-1440”. These are the extent dates of PAGES Arc_39’s MD95-2011’s alkenones. Odd.

    Steve: Longyearbyen is an alias for Lomonosovfonna, Svalbard.

  12. MikeN
    Posted Oct 8, 2014 at 8:20 PM | Permalink

    Are you using the corrected Pages Arctic or the original?

    Steve: depends what you’re looking at. I generally tried to specify. .

  13. scf
    Posted Oct 8, 2014 at 11:07 PM | Permalink

    Fascinating. Figure 2 in particular is fascinating. Both reconstructions have so much similarly until you reach Kaufman’s hockey blade. So one can conclude there are Kaufman proxies that diverge wildly from most other proxies but only in the last century. It’s the earlier agreement that really says something about the later disagreement, that the later disagreement cannot be temperature related if one assumes that the earlier agreement is caused by temperature.

    Steve: I agree with you about the apparent impact of non-temperature series. The contaminated Igaliku proxy is one that fits this bill. Astonishingly, Kaufman didn’t remove all the contamination in their amendment. I cant tell whether they goofed or it was intentional.

  14. Posted Oct 9, 2014 at 8:12 PM | Permalink

    > Korhola’s involvement in the present project is salutary as Korhola, unlike Tingley’s coauthor in Tingley and Huybers, is familiar enough with the data to know when it is pointing up or pointing down and not to use data that has been agriculturally contaminated.

    In the section **Acknowledgement**, we can read:

    We thank Sami Hanhijärvi and Atte Korhola for compiling the original version of the PAGES Arctic 2k database, and the many colleagues who kindly made digital versions of their data available for this product.

    Was there any problem with the original version?

    • Steven Mosher
      Posted Oct 10, 2014 at 10:48 AM | Permalink

      That is all

2 Trackbacks

  1. […] […]

  2. […] now to: Revisions to Pages2K Arctic / Okshola: which way is up?  / PAGES2K: More Upside Down? and PAGES2K vs the Hanhijarvi Reconstruction and which a the time of completing this article spans now to Warmest, uh, Since the Medieval Warm […]


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