Friday, April 13, 2012

3409.txt

cc: 'Michael Grabner' <michael.grabneratXYZxyzu.ac.at>, t.m.melvin@uea.ac.uk, Reinhard Boehm <Reinhard.BoehmatXYZxyzg.ac.at>, 'Phil Jones' <p.jonesatXYZxyz.ac.uk>, 'Maurizio Maugeri' <maurizio.maugeriatXYZxyzmi.it>, 'Michele Brunetti' <m.brunettiatXYZxyzc.cnr.it>, jan.esper@wsl.ch, 'Ulf Buentgen' <buentgen@wsl.ch>
date: Thu Dec 14 14:37:45 2006
from: Keith Briffa <k.briffaatXYZxyz.ac.uk>
subject: Re: AW: A plot
to: David Frank <david.frankatXYZxyz.ch>, Kurt Nicolussi <kurt.nicolussiatXYZxyzk.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 B�ntgen 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
-----Urspr�ngliche 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.jonesatXYZxyz.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 f�r Wald, Schnee und Landschaft WSL
Pal�o-Klimatologie
Z�rcherstrasse 111
CH-8903 Birmensdorf
+41 44 7392 282
+41 44 7392 215
david.frankatXYZxyz.ch
[2]http://www.wsl.ch
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--
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/

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