Monday, March 5, 2012

2393.txt

cc: k.briffaatXYZxyz.ac.uk
date: Fri, 11 Feb 2005 08:54:23 +0000
from: Phil Jones <p.jonesatXYZxyz.ac.uk>
subject: Re: FW: SCEPTICS
to: Tim Osborn <t.osbornatXYZxyz.ac.uk>, "Folland, Chris" <chris.follandatXYZxyzoffice.gov.uk>

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Chris,
Sending again as Tim seems to have spelt UEA wrong in Keith's
email address.

Phil


Chris,
In addition to Tim's comments, here are a few of mine.

1. As you know IPCC is an Assessment, not a review.
2. The Huang et al paper in 1997 is quite different from later
ones nearer 2000. I don't see how their method of curve
development can generate a warmer MWP.
3. The 1998 Holocene paper didn't have the years beyond the
early 1990s and then the number of proxies was reduced
from a few to very few.
4. In the 2001 and earlier IPCC tomes you tended to show one
series at high-freq with others at low-freq (decadal) at least
for instrumental. I presume you were just doing this for the
paleo series.
5. The 2001/2 Briffa et al paper came out after the TAR. This one
had a series to 1400. The 2000 paper is based on 3 tree-ring series.
6 There are 2 ways of producing long paleo series.
- one a la MBH taking all proxies and having an increasing number
with time and even longer instrumental from the 18th century on.
- pick a subset of proxies that mostly go back to 1000 or AD 1, then
just average these. This is the approach we took in The Holocene in
1998. Also this is done in MJ2003, Crowley and most recently in
Esper et al and Moberg et al.

Apologies for brief comments but off again tomorrow for 8 days in Pune.

Cheers
Phil


At 09:19 08/02/2005, Tim Osborn wrote:
>Chris,
>
>I've attached electronic reprints of the two relevant papers. In both
>cases the figures are rather low resolution. For the Briffa et al. paper
>I've also included better resolution copies of the 3 colour plates as
>separate files.
>
>At 21:43 07/02/2005, Folland, Chris wrote:
>>The original Briffa graph (published in Quaternary Science Reviews in 2000)
>>also reaches peak values in the 11th century, but this is not visible in the
>>IPCC presentation since the first 400 years were left out (why?).
>
>Important point! The real reference for the Briffa curve shown in the
>IPCC TAR is Briffa et al. (J. Geophys. Res., 2001 - the attached reprint)
>and goes back only to 1400, as shown in the TAR. Although this paper was
>published in January 2001, I think it was too late to put in the final
>reference including page numbers. I don't know how it got attributed to
>Briffa (Quaternary Science Reviews, 2000) because that shows a completely
>different reconstruction which does go back to 1000, but which was based
>on tree-ring width not tree-ring density and from only three sites in
>northern Eurasia.
>
>If you also want a copy of the QSR 2000 paper, then you'll need to ask
>Keith because I don't have an electronic copy.
>
>Best wishes
>
>Tim
>
>
>
>
>
>
>
>
>Dr Timothy J Osborn
>Climatic Research Unit
>School of Environmental Sciences, University of East Anglia
>Norwich NR4 7TJ, UK
>
>e-mail: t.osbornatXYZxyz.ac.uk
>phone: +44 1603 592089
>fax: +44 1603 507784
>web: http://www.cru.uea.ac.uk/~timo/
>sunclock: http://www.cru.uea.ac.uk/~timo/sunclock.htm

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
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