4101.txt
cc:
[email protected]
date: Thu, 7 Nov 2002 23:56:46 -0500
from: “
[email protected]” <
[email protected]>
subject: RE: CCDD
to:
[email protected]
Hi Phil,
Thanks for the added info. If Mike said that my calibration procedure is
“flawed”, I will be extremely pissed off. His grad student just submitted a
paper to The Holocene, with Mike and I as co-authors, that compares my
point-by-point method with his RegEM method (Keith should have received the
paper by now). There are “modest” improvements in some areas using RegEM,
but overall the two methods produce statistically identical results on a
regional basis.
Indeed, it is mentioned in the paper that the P-B-P method
could be improved by adding a dynamic search radius for each grid point,
thus making it even closer to RegEM and maybe even better. Indeed, the
P-B-P method produces classical calibration period information and
estimates that are very useful in understanding the fitted models. In
contrast, RegEM does not produce any such useful information and thus
operates much more as a “black box”.
Re standardization and low-frequency stuff, the vast majority of the
tree-ring chronologies have been standardized to preserve variance at least
up to 100 years (and generally more). I also agree with you that PDSI ought
not to have a great deal of multi-centennial variability because it is
dominated by precipitation, which is dominated by high-frequency, nearly
white, variance. I am surprised that Tom Karl does not seem to understand
that.
In all candor now, I think that Mike is becoming a serious enemy
in the way that he bends the ears of people like Tom with words like “flawed” when
describing my work and probably your and Keith’s as well. This is in part a
vindictive response to the Esper et al. paper.
He also went crazy over my
recent NZ paper describing evidence for a MWP there because he sees it as
another attack on him. Maybe I am over-reacting to this, but I don’t think
so.
Cheers,
Ed