Monday, March 12, 2012

2409.txt

cc: lbutleratXYZxyzr.edu, k.briffaatXYZxyz.ac.uk
date: Wed, 2 Jun 1999 11:19:35 -0600 (MDT)
from: Tom Wigley <wigleyatXYZxyzker.ucar.edu>
subject: Re: Paleo and Balling
to: Phil Jones <p.jonesatXYZxyz.ac.uk>

Thanks, Phil. I've faxed a copy to Tom in Copenhagen.

Lisa

On Tue, 1 Jun 1999, Phil Jones wrote:

>
> Lisa,
> Tom requires this for a public debate he's having with
> Michaels and other skeptics on June 7. He tells me he's in
> Denmark at the moment. I couldn't get something to him yesterday
> as it was a holiday here. Can you forward the reply to him ?
>
> Cheers
> Phil
>
> Tom,
> Keith's in the Ural mountains for the next two weeks. You
> probably emailed Malcolm re this one Utah chronology. As you say
> this is one chronology, but Balling shouldn't have reconstructed
> ANNUAL temperature. This may only work as the growing season is
> part of the year. Malcolm may know if this is a good site for
> temperature, also what standardization, if any, was used. Balling
> doesn't say what r-squared he got or anything about Calib/Verif
> or why the tree width series was deautocorrelated. So I would
> say single site is the main point to make and his detail-less
> calibration. Balling wouldn't accept a global/hemipsheric
> temperature series based on one station - so why accept one
> based on on tree series. He quotes an r value of 0.45, which is
> not very high !
>
> Looking at Balling's figure (#1) it would seem from the skew
> of his reconstructions that he has an inverse relationship
> with temperature (ie it's really precip that the trees respond
> to). I would expect 'real' annual temps in Utah to be -vely
> skewed. Ring widths will be -vely skewed. He has +ve skew in the
> reconstruction, hence the presumed inverse relationship. Despite
> his small r value of 0.45, he has quite a range in the
> reconstruction. I would doubt whether Utah could get 4C warmer
> in a year.
>
> If you use many more proxy series ( tree rings/ widths, ice
> cores, historical etc) then you get a different view of the
> past 1000 years. The papers to mention are
>
> a) Jones et al (1998) in The Holocene 8 467-483.
>
> b) Mann et al (1998) Nature 392 779-787 and GRL(1999) 26, 759-762.
>
> c) Briffa et al (1999) Science compass piece in early May.
>
> All 3 use different sets of paleo series ( Jones 17 long series,
> Mann about 100 and Keith about 400 density series).
>
> All conclude that 20th century is the warmest of the millennium
> and the warming during it unprecedented since 1400. All
> centuries this millennium are cooler than the 1961-90 base
> period - the 20th by about -0.05 and the 17th (coldest) 0.5
> below 1961-90. Warmest century in the first half of the
> millennium was about 0.1-0.2 below 1961-90. Range of values
> of decades over the last 1000 years is quite small - 1990s
> about 0.35 and 1601-1610 -0.7. Even the coldest year of 1601
> was only about 1 C below 1961-90. This level of variability of
> hemipsheric average temperature is in accord with the long
> model control runs and the few runs with solar forcing since
> ~ 1650.
>
> Hope this is of some use.
>
> 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
>
> ----------------------------------------------------------------------------
>
>
>


**********************************************************
*Tom M.L. Wigley *
*Senior Scientist *
*National Center for Atmospheric Research *
*P.O. Box 3000 *
*Boulder, CO 80307-3000 *
*USA *
*Phone: 303-497-2690 *
*Fax: 303-497-2699 *
*E-mail: wigleyatXYZxyzr.edu *
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