Sunday, April 1, 2012

3076.txt

cc: Jan Esper <esperatXYZxyz.ch>, anders.moberg@natgeo.su.se, Eduardo.Zorita@gkss.de, hegerl@duke.edu, k.briffa@uea.ac.uk, m.allen1@physics.ox.ac.uk, weberatXYZxyzi.nl
date: Fri, 6 Jul 2007 16:23:18 +0100
from: Martin Juckes <m.n.juckesatXYZxyzac.uk>
subject: Re: Mitrie
to: Tim Osborn <t.osbornatXYZxyz.ac.uk>

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Thanks to Tim and Keith for that correction.

I've inserted that, and also reworded the paragraph in the conclusions which
talked about "serious flaws" along the lines suggested by Tim. It now reads:
"The IPCC2001 conclusion that temperatures of the past millennium
are unlikely to have been as warm, at any time prior to the 20th
century, as the last decades of the 20th century is supported
by subsequent research and by the results obtained here.
We have also reviewed and, in some cases, tested with new
analysis, papers which claim to refute that IPCC2001 conclusion and
found that their claims are not well supported."

This version attached with the revised supplementary material.
I need to go over the `changes' document again, and the response, but I hope
to send it in on Monday.

cheers,
Martin

On Wednesday 04 July 2007 16:54, Tim Osborn wrote:
> Hi Martin & Jan (and others)
>
> Keith and I have put together the attached text as an alternative,
> hopefully more accurate, version to the current paragraph about
> differences between tree series. We did this before/while Jan's
> email arrived, so some overlap but hopefully what we say is
> compatible with Jan's comment. Note we haven't discussed the ice
> core data from Fisher, just the tree-ring series.
>
> How does the attached sound?
>
> Cheers
>
> Tim
>
> At 22:15 03/07/2007, Jan Esper wrote:
> >Martin
> >This is quite a task, as I do not really remember which version of a
> >dataset was used in which paper.
> >
> >For ECS2002, I detrended all data via two RCS runs applied to the
> >"linear" and "non-linear" sub-groups as identified in that paper.
> >All data except for Boreal and Upper Wrigth (both from Lisa
> >Graumlich) and Mongolia (from Gordon Jacoby) were measured at WSL.
> >
> >I wouldn't necessarily claim that the regional chronologies from the
> >ECS approach are highly useful records, i.e. for a regional analysis
> >I would use data that are detrended region-by-region.
> >
> >(Šthat used by ECS2002 is based on the same tree-ring data as that
> >used by MSH2005, but with a different standardisation method.)
> >Not fully sure what MSH2005 did, but this is very likely correct,
> >i.e. they likely used a "regional" version from Briffa and/or Grudd.
> >
> >(The Fennoscandia data used by JBB1998, MBH1999 also come from the
> >Tornetraesk area, but from a different group of trees.)
> >Hm..., I don't believe that these studies used different trees. Up
> >to the recent update by Hakan Grudd, that is currently in review
> >with Climate Dynamics, there was effectively only one dataset from
> >Tornetrask. Keith or Tim might know this better.
> >
> >(The Polar Urals series used by ECS2005 is also a reanalysis of the
> >data used to create the Northern Urals series used by JBB1998, MBH1999.)
> >I wouldn't necessarily call this a reanalysis. Perhaps better say
> >'differently detrended'. Anyway, I doubt that there is a long
> >dataset from the Northern Ural as there is little wood preserved in
> >that area. This is likely the same data, i.e. both are Polar Ural.
> >
> >(The Taymir data used by HCA2007 is a smoothed version of that used
> >in ECS2002, MSH2005.)
> >This I really don't knowŠ but it would be better to use a regionally
> >detrended version of the data...
> >
> >(The Greenland stack data used by MBH1999 is a composite of data
> >analysed by \citet{fisher_etal1996}, but the precise nature of the
> >composite is not described by \citet{fisher_etal1996}.")
> >Agreed. Just read the paper again, and it is indeed difficult to say
> >which data was combined.
> >
> >(I've kept the phrase about "serious flaws" in the conclusion,
> >despite Tim's suggestion, supported by Nanne, of a weaker wording,
> >because I think it is important to draw attention to the serious
> >flaws which are there.)
> >I also think that a less aggressive wording would be more effective.
> >
> >-- Jan
> >
> >
> >
> >
> >At 16:41 Uhr +0100 3.7.2007, Martin Juckes wrote:
> >>Hello,
> >>
> >>another version of our paper is attached.
> >>
> >>I've added the following paragraph to the discussion of Table 1, and I'd
be
> >>grateful if Jan and Keith could check that it is accurate:
> >>"Evaluation of past work is further compicated by confusion between
closely
> >>related proxy series. In Tab.~1 there are two series referred to as
> >>Tornetraesk: that used by ECS2002 is based on the same tree-ring data as
that
> >>used by MSH2005, but with a different standardisation method. The
> >>Fennoscandia data used by JBB1998, MBH1999 also come from the Tornetraesk
> >>area, but from a different group of trees. The Polar Urals series used by
> >>ECS2005 is also a reanalysis of the data used to create the Northern Urals
> >>series used by JBB1998, MBH1999. The Taymir data used by HCA2007 is a
> >>smoothed version of that used in ECS2002, MSH2005.
> >>The Greenland stack data used by MBH1999 is a composite of data analysed
by
> >>\citet{fisher_etal1996}, but the precise nature of the composite is not
> >>described by \citet{fisher_etal1996}."
> >>
> >>I've also moved a few things around and tried to follow most of the
> >>suggestions from Anders and Nanne. I've kept the phrase about "serious
flaws"
> >>in the conclusion, despite Tim's suggestion, supported by Nanne, of a
weaker
> >>wording, because I think it is important to draw attention to the serious
> >>flaws which are there. One reviewer has implied that we should not discuss
> >>flawed work at length because in oding so we give it credibility it does
not
> >>deserve. I believe that since this stuff is published and influential in
some
> >>quarters we should discuss it and draw attention to the fact that it is
> >>seriously flawed.
> >>
> >>cheers,
> >>Martin
> >>
> >>Attachment converted: Hennes:cp-2006-0049-rv 3.pdf (PDF /«IC») (001588D6)
> >
> >
> >
> >--
> >
> >Jan Esper
> >Head Dendro Sciences Unit
> >Swiss Federal Research Institute WSL
> >Zuercherstrasse 111, 8903 Birmensdorf, Switzerland
> >Voice: +41-44-739 2510 or +41-44-739 2579
> >Fax: +41-44-739 2515http://www.wsl.ch/staff/jan.esper
>


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