Wednesday, March 14, 2012


cc: Keith Briffa <>, Phil Jones <>, "Michael E. Mann" <>, Scott Rutherford <>
date: Fri, 18 May 2001 09:58:38 -0400
from: Ed Cook <>
subject: Re: Comments on "Extending NAO Reconstructions ..."
to: Juerg Luterbacher <>

Hi Juerg,

My comments on the error limits was intended as much to elicit comments and
discussion as anything else. So, I am not necessarily suggesting that you
change anything in your paper. What you have done is fine as far as it
goes. And as Mike says, it is a good first step. Again as I said
previously, I may be completely wrong here, which I am willing to accept if
someone can convince me that the defined histories of variation in the
proxies used for reconstruction doesn't matter to the estimation and
interpretation of the error limits. It is not obvious to me that that is
the case. The existence of errors in the predictors also tells me that some
other method of regression analysis might be tried which explicitly allows
for errors in both the predictors and predictand. Doing this could strongly
affect the SE of the estimate on the predictand in ways that I wouldn't
care to predict. Much work needs to be done here.



>Hello Ed
>I just came back and saw all your mails and the
>interesting discussion on the uncertainty ranges
>of the reconstructions. I will now see how to
>proceed, I will calculate the 1sigma estimates
>and then decide what to show. In addition, we
>intend to show the interannual variability
>rather than the low frequency variability, so
>the errors are calculated for each winter.
>Thank you very much again for everything and till
>Have a nice weekend

Dr. Edward R. Cook
Doherty Senior Scholar
Tree-Ring Laboratory
Lamont-Doherty Earth Observatory
Palisades, New York 10964 USA
Phone: 845-365-8618
Fax: 845-365-8152

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