cc: "k.briffa@uea.ac.uk" <k.briffa@uea.ac.uk>
date: Wed, 3 Apr 2002 07:52:50 -0500
from: "drdendro@ldeo.columbia.edu" <drdendro@ldeo.columbia.edu>
subject: RE: RE: Fwd: RE: Recent NH reconstruction
to: "t.osborn@uea.ac.uk" <t.osborn@uea.ac.uk>

Hi Tim,

I will be sure not to bring this up to Mike. As you know, he thinks that 
CRU is out to get him in some sense. So, a very carefully worded and 
described bit by you and Keith will be important. I am afraid that Mike is 
defending something that  increasingly can not be defended. He is 
investing too much personal stuff in this and not letting the science 
move ahead. I am afraid that he is losing out in the process. That is too 
bad.

Cheers,

Ed

Original Message:
-----------------
From: Tim Osborn t.osborn@uea.ac.uk
Date: Wed, 03 Apr 2002 13:28:18 +0100
To: drdendro@ldeo.columbia.edu, k.briffa@uea
Subject: RE: Fwd: RE: Recent NH reconstruction


At 13:01 03/04/02, you wrote:
>Hi Tim,
>
>Thanks for the data. It is good to have it all in one file like that. I 
>honestly
>hadn't read your "breezy" article (that Mike hates so much) closely
>enough to realize the extent to which you recalibrated everything. That 
is
>fine, of course, to make all comparisons comparable. What surprised
>me the most was that you were able to use Mann et al. data from only
>land areas north of 20N. Mike's big argument has been that his series
>would gain some amplitude of multi-centennial low-frequency
>variability is the tropics were not included. Yet your results indicate 
that
>that is not the case, at least by much. I go down to Mike's place to give 
a
>seminar tomorrow. I am sure that he will fill my ears with more of his
>complaints.

Ed - your are spot on about the tropics/extra-tropics issue.  Keith or I 
will be responding to Mike to say exactly that, as soon as we have a 
spare 
half hour (been a bit hectic with proposals & reports recently).  We 
didn't 
clarify it in the perspectives piece because of lack of space, but we 
have 
extracted only the land boxes and only those north of 20N from his 
spatially-resolved reconstructions and it gives virtually the same 
answer 
(in fact they give correlated time series but with different variance, but 
when both his full NH or his land north of 20N are calibrated against 
the 
instrumental land north of 20N, the calibration brings them very close to 
each other).

This completely removes most of Mike's arguments.  It's somewhat 
surprising 
that he makes the argument because I did the extraction when I visited 
him 
in Oct 2000 and showed him it makes no difference after 
re-calibration!  We'll tell him soon and see what he says.  He may then 
raise the (partly valid) point that the pre-1400 period of his 
reconstruction was based on only one EOF and they said in their GRL 
paper 
that only the full domain (i.e. full NH) should be used before 1400.

Do you know if he's going ahead with a complaint letter to Science?

Please don't forward this to Mike or anyone else - we want to take time 
to 
phrase it just right ["wording is *so* important", Mike Mann quotation 
following our last perspectives piece in 1999 ;-) ], though if the issue is 
raised at your seminar tomorrow you can tell him that what we did in 
our 
figure.  It's understandable that he assumed we'd used his full NH 
record - 
I'm sure most other people assumed the same.  The point is that it's 
not a 
peer-reviewed piece and was simply intended to highlight the broad 
issues 
that your work with Esper helps to address - and I think we succeeded 
in that.

Best wishes

Tim


Dr Timothy J Osborn                 | phone:    +44 1603 592089
Senior Research Associate           | fax:      +44 1603 507784
Climatic Research Unit              | e-mail:   t.osborn@uea.ac.uk
School of Environmental Sciences    | web-site:
University of East Anglia __________|   http://www.cru.uea.ac.uk/~timo/
Norwich  NR4 7TJ         | sunclock:
UK                       |   http://www.cru.uea.ac.uk/~timo/sunclock.htm

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