cc: 'Michael Grabner' <michael.grabner@boku.ac.at>, t.m.melvin@uea.ac.uk, Reinhard Boehm <Reinhard.Boehm@zamg.ac.at>, 'Phil Jones' <p.jones@uea.ac.uk>, 'Maurizio Maugeri' <maurizio.maugeri@unimi.it>, 'Michele Brunetti' <m.brunetti@isac.cnr.it>, jan.esper@wsl.ch, 'Ulf Buentgen' <buentgen@wsl.ch>
date: Thu Dec 14 14:37:45 2006
from: Keith Briffa <k.briffa@uea.ac.uk>
subject: Re: AW: A plot
to: David Frank <david.frank@wsl.ch>, Kurt Nicolussi <kurt.nicolussi@uibk.ac.at>

   Hi David and others
   The resilience of the tree-ring information , I agree , seems only to be enhanced by the
   multiple data set comparison. The issue of the specific "band limited" calibration is an
   important one here , in as much as the different data sets will require different optimal
   scaling (calibrations) , and the reconstructions should be considered along with their
   appropriate uncertainty bands. Your remarks on the density , support our ideas regarding
   the possibility (or even desirability ) of using "band specific calibrations" , as we
   discussed in the paper by Tim and myself (resurrecting the original idea by Joel). It is
   desirable to show the separate band reconstructions (and verification performance and
   regression coefficients) . Having said all this , it remains likely that difference between
   temperature and tree indices is pervasive .
   I was interested also to see that in a previous message ( as copied by Kurt) that your
   group is working on putting all the long Alpine temperature sensitive tree-ring data
   together - we ( Tom and I with Kurt and Michael) were also working towards this (hopefully
   with the benefit of the data your group has published) as originally outlined in the
   ALP-IMP plans, and I wonder what the precise plans you have ? We would not like to work at
   cross purposes. Cheers
   Keith
   At 12:24 14/12/2006, David Frank wrote:

     Dear Kurt (and all others).
     Thanks for the nice figures. I can only agree with your demonstration
     and point that a combination of all suitable data should produce a
     more robust estimate for past temperature trends.
     It is more and more apparent that any record which we consider a
     temperature proxy underestimates the early instrumental warm season
     warmth. The general tendencies displayed by the newer datasets that
     you show, seem to be consistent with some comparisons between the
     early instrumental records and other previously described tree-ring
     recons. However, in response to Reinhard's question to the
     tree-ringers, I could easily say there could be a whole variety of
     reasons why the tree-ring data contain more low-frequency variability
     than they should. The troubling part is that we can, and have,  put
     out lots of hypotheses why these records all tend to "undershoot" the
     early instrumental data.
     From your graphs (and other quicker comparisons that i have done), it
     appears that Ulf's LADE-MXD record slightly underestimates the recent
     warming trend in the last 20 or so years in comparison to most other
     records (and also the instrumental data). During the earlier periods
     it seems to generally fall in the middle of the crowd and also
     captures the higher-frequency variability in the inst. records very
     well over a 240 year period. It seems like an advantage to be able to
     see how as many independent records as possible lie on the spaghetti
     plate.
     Perhaps, Keith or Tom have some helpful insights... Any thoughts on
     biological autocorrelation(esp. for MXD data) and detrending issues?
     best wishes,
     David
     Quoting Kurt Nicolussi <kurt.nicolussi@uibk.ac.at>:

     Dear Reinhard et al.,
     here some plots (attached file) based on slightly different
     chronologies from Alps - the well know Bntgen et al. larch MXD, the
      Tyrol spruce MXD, the Pinus cembra TRW and a new Larch chrono
     (region of the Tyrol, combination of living trees, hist. and
     subfoss. material - RCS, power transformation) - the first two plots
      show the four series, single years and about 20 year smoothed, the
     other show some comparisons between the combined 4 chrono's and
     temperature data - especially the last plot indicates that the
     residuals are much better for the combined record.
     best regards
     Kurt
     Jan Esper wrote:

     Dear Reinhard et al., this is a fascinating discussion and enjoyed
     very much looking at the files you sent earlier. I just wanted to
     add that it would be great if you could wait a bit more until Dave
     came up with some first ideas on optimally combining all the
     long-term tree-ring data (that might not take too long anymore). I
     am absolutely convinced that we will produce an improved record
     including all the new tree-ring data, and that this record will
     include useful error estimates which might serve as an agrument to
     do more or less adjustments to the early instrumental data. I am
     also pretty sure that the combined record will consider certain
     frequency bands from certain datasets and parameters. Best wishes
     --Jan
     At 14:04 Uhr +0100 13.12.2006, Reinhard Boehm wrote:

     Dear Phil, Maurizio and Michele,
     Please apologise me not taking part actively enough in our
     discussion at the
     moment. The reason is, that since the beginning of last week I am
     confronted
     with a really incredible "hype" of the media which eats up all my time. The
     reason was a half-page message of our press-manager to the APA (Austrian
     press Agency) about the final ALP-IMP report. Since then I have done not
     much more than talking and writing about climate change topics, most of it
     not in relation to the project but about this year's warm autumn, these
     weeks winter tourism problems in the Alps and so on.
     So please do not believe I'm not anymore interested in our topic, I follow
     all your mails and I only want to tell you that I am also more tending to
     believe that may first version, to fit the early period exactly to the
     TR-series, may be somehow exaggerated. So Phil's last proposal, to adjust
     the JJAS by a bit less than I did, seems to make sense also to me. And I
     also think that something like a Zero-adjustment for winter would be the
     best solution. The only thing we should consider would be how to describe
     our arguments for doing so. I would also be interested about the opinion of
     the treering group about that:
     As you see, we "instrumentalists" have now come to a point short before
     deciding on a definite set of monthly adjustments for the early
     instrumental
     series which we think should be somewhat less than the total offset versus
     the TR-series. Do you have arguments to support this? Do you have ideas why
     TR-series tended to systematically towards a cold bias in these years?
     Best regards
     Reinhard
     -----Ursprngliche Nachricht-----
     Von: Phil Jones [[1]mailto:p.jones@uea.ac.uk]
     Gesendet: Mittwoch, 13. Dezember 2006 12:32
     An: Maurizio Maugeri; Reinhard Boehm
     Cc: Michele Brunetti
     Betreff: A plot
     Thanks Michele !
     The first of the two plots is the one I'm talking about.
     Dear All,
           Apologies for filling your boxes. Here is a plot.
     This is for average JJA (daily) temps for 1961-90 (red) and 1772-1820
     (black).
     This is all daily T. The middle lines are the averages, the outer solid
     lines
     are the 1st and 9th deciles (10the and 90th percentiles) and the dotted
     lines are the absolute extremes for Tmean.
        A plot like this for Milan or somewhere else in Northern Italy
     would be interesting.
        This implies to us that CET is OK. This makes it harder to
     change your summers that much - well not as much as NITA
     would imply.
     Cheers
     Phil
     Prof. Phil Jones
     Climatic Research Unit        Telephone +44 (0) 1603 592090
     School of Environmental Sciences    Fax +44 (0) 1603 507784
     University of East Anglia
     Norwich                          Email    p.jones@uea.ac.uk
     NR4 7TJ
     UK
     ----------------------------------------------------------------------------

     --
     Ao.Univ.Prof. Dr. Kurt Nicolussi
     Tree-ring Group / Institute of Geography
     University of Innsbruck
     Innrain 52
     A-6020 Innsbruck
     Tel +43 512 507 5673
     Fax +43 512 507 2806

     --
     David Frank
     Eidg. Forschungsanstalt fr Wald, Schnee und Landschaft WSL
     Palo-Klimatologie
     Zrcherstrasse 111
     CH-8903 Birmensdorf
     +41 44 7392 282
     +41 44 7392 215
     david.frank@wsl.ch
     [2]http://www.wsl.ch
     -----------------------------------------------------------------------------------
     This message was sent using IMP ([3]http://horde.org/imp/) at WSL
     ([4]http://www.wsl.ch).

   --
   Professor Keith Briffa,
   Climatic Research Unit
   University of East Anglia
   Norwich, NR4 7TJ, U.K.

   Phone: +44-1603-593909
   Fax: +44-1603-507784
   [5]http://www.cru.uea.ac.uk/cru/people/briffa/

