cc: k.briffa@uea.ac.uk
date: Mon, 8 Apr 2002 07:55:05 -0400
from: Edward Cook <drdendro@ldeo.columbia.edu>
subject: Re: Fwd: RE: Recent NH reconstruction
to: Tim Osborn <t.osborn@uea.ac.uk>

<x-flowed>
Hi Tim,

Some quick questions, comments, and a request. First, when you say 
that you recalibrated all of the series shown in your windy 
perspectives bit, what time period did you recalibrate all the series 
over? Was it the same for all series? Just to be clear here, I 
thoroughly dislike the pre-1900 instrumental data. That pre-1900 
warming back to 1860 or so is very suspicious. No large-scale pure 
proxy estimates have ever been able to reproduce it. Only the MBH 
series does because it includes instrumental data. Thus, 
recalibrating the proxies using pre-1900 observed data may be biasing 
the results. That is why I did not use the pre-1900 data in my 
calibration. Phil would probably disagree strongly with me here, 
perhaps you and Keith too, but that is my opinion. Also, how did you 
express all series as anomalies from the observed 1961-1990 mean when 
not all series extended out to 1990 (e.g. Briffa1, Mann)? I honestly 
dislike such short anomaly periods in any case, especially when the 
data are trendy. It unnaturally distorts the visual expression of the 
data (my opinion anyway). Finally, can you send me the unfiltered 
observed land-only data that you used?

Cheers,

Ed
-- 
=================================
Dr. Edward R. Cook
Doherty Senior Scholar
Tree-Ring Laboratory
Lamont-Doherty Earth Observatory
Palisades, New York  10964  USA
Phone: 1-845-365-8618
Fax:   1-845-365-8152
Email: drdendro@ldeo.columbia.edu
=================================
</x-flowed>
