cc: Shaopeng Huang <shaopeng@umich.edu>
date: Thu, 9 Mar 2000 14:54:44 -0500 (EST)
from: "Henry N. Pollack" <hpollack@geo.lsa.umich.edu>
subject: Re: Nature paper and beyond
to: Phil Jones <p.jones@uea.ac.uk>

Hi Phil,

I share your skepticism about LIA and MWP being global events. The North
Atlantic region is where they have been best documented, and I suspect
there has been a bandwagon effect in looking for (and finding?) some hint
of these events elsewhere.

As for sub-ensembles, or regional ensembles, of our 1997 GRL paper
geothermal data, that is of course something we can try. Shaopeng and I
much earlier had separated them hemispherically, and the northern
hemisphere had a bigger signal than the southern hemisphere. As I
mentioned earlier, that particular dataset (not the typical T vs. z
profiles, but rather a cruder estimate of heat flow q vs. z) is a 
noisy dataset, and because we rely on statistics of large numbers to help
with signal enhancement, we did not try to push very far in subdividing
it. But we can resurrect that dataset and have a closer look.

Have a good trip wherever you are going; we'll take up the discussion
again later.

Cheers,
Henry

-------------------------------------------------------
On Thu, 9 Mar 2000, Phil Jones wrote:

> 
>  Henry,
>    I've just been copying a few papers, so I've got some reading material
>  for next week when I'm away. The Werner et al (2000) paper in GRL has yet
>  to reach us, so that will have to wait.
> 
>    A couple of quick comments. I'd seen the Dahl-Jensen et al paper on the
>  Greenland borehole record. I'm happy with the warmth this record gets in
>  that area around AD 1000. It also seems mild in some of our long European 
>  trees and there is a lot of evidence from documentary sources for mildness
>  in Europe at this time. Basically all this is the evidence for the MWP.
>  The longer records we have from elsewhere suggest a different course of
>  change over the millennium than the Euro/N.Atlantic view. Many people assume
>  that this Euro/N.Atlantic view applies elsewhere. I'm of the opinion it 
>  doesn't and also that if developments in paleo and long historical evidence
>  had been from somewhere else (say Australia rather then Europe) 
>  pre-conceptions of the past would be quite different. A crusade to
>  re-educate people ! 
> 
>  Your paper in 1997 in GRL really needs to be looking
>  at boreholes in different regions, rather than integrating them together.
>  Are there any long SH boreholes ?  or any in western US ( away from
>  Greenland). Am I being naive in suggesting analysing a network of
>  boreholes as we do in some paleo/instrumental work ? 
> 
>   I have to read the other papers !  I'll get back to you when I have.
> 
>   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
> 
> ----------------------------------------------------------------------------
> 
>     
>