date: Thu, 06 Apr 2006 12:45:16 +0100
from: Tom Melvin
subject: Re Hakan
to: Keith
Keith,
I read Hakan's draft and find problems.
Would it be possible for you to ask Hakan to send his updated (and
original) measures, TRW, MXD and Pith estimates for testing purposes?
The problem is that the update chronology appears to have a different
growth rate to the original and this removes the growth increase of
the modern century and hides the sensitivity problem. Both feature in
Hakan's conclusions.
Mean MXD for old trees of 0.58 is considered similar to the mean for
new trees at 0.57, but considering the slope of the RCS curve and the
mean age of the constituent rings the new data should have a much
larger mean density than the old data.
The presumption that the MXD chronology is "correct" and that the TRW
chronology has excess slope over the modern period (Figures 4 and 9)
may be wrong.
Signal-Free methods and BFM would offer a second opinion. They
managed to reduce the excesses of the few < 50 old, very fast growing
trees, of the 2002 paper Tornetrask chronology.
I have a few detailed comments I will let you have later.
The MXD data would be useful to the "Sensitivity" review paper if
Hakan is happy for it to be used.
Tom
Tom Melvin
Climatic Research Unit
University of East Anglia, Norwich, NR4 7TJ, U.K.
Phone: +44-1603-593161 Fax: +44-1603-507784