date: Thu, 28 Jun 2007 11:19:31 -0600
from: Kathreen Ruckstuhl <kruckstuatXYZxyzlgary.ca>
subject: Re: Philosophical transactions
to: Tom Melvin <t.m.melvinatXYZxyz.ac.uk>, Keith Briffa <k.briffaatXYZxyz.ac.uk>
Dear Keith and Tom,
Please find below the last reviewer's comments on your paper. Please
also make sure that you deal with them and send me a list of the changes
you made. This also applies to the minor changes suggested by the first
Best wishes and thanks again for this excellent contribution!
Review of `Trends in recent Temperature and Radial Tree Growth spanning
2000 years across Northwest Eurasia`, by Keith R. Briffa et al.
Overall, I liked the paper. I value the findind that the strenght of
climate-tree growth relationships has not declined during the 20th
century, as this has been the cause of debate in the last years since a
paper published ironically by the same author in 1998 (Briffa et al.
1998). This gives tree-ring-based temperature reconstructions in the
area credibility and enables the authors to state that the 20th century
has been unprecedented in terms of high temperatures in the last 2
millenia in NW Eurasia. The analyses are easy to understand, practical
and useful in getting to the point of the paper.
I have no major comments in a general sense. Sometimes the text might be
a bit confusing, the sentences too long and grammatically complex, with
some commas missing that make things difficult to understand, and the
structure of the paper not pertfectly fluid, but I would not say it
represents a problem overall. My only comments are punctual and come here:
*1.* Page 3. Lines 10-12. This sentences refer to the Arctic
Amplification: the Arctic amplification has caused a great debate in the
last decade which does not appear in here. Whereas many authors claim
that temperatures in Northern latitudes will increase more than in the
temperate areas due to the ice-albedo feedback (e.g. Serreze and Francis
2006), some others claim that this is not the case in observed values
(e.g. Polyakov et al. 2002). A reference to this debate could be useful.
*2.* Page 5. Line 2. Erase the word �that� or else the sentence is not
*3.* Page 6. Lines 1-8. The �RCS method� was termed this way by Briffa
et al. 1992, but the same method had been applied by other authors way
before (Erlandsson 1936; Fritts 1976). I would appreciate the earlier
references in the text.
*4.* Page 7. Line 33. I�d add a comma between �millenia� and �two�.
*5.* Page 7. Line 35 and lines 8-10. After stating that regional
chronologies have practically nothing to do with each other, the authors
built a NW-Eurasian chronology, which they will only use once and in a
minor analysis which unnecessary for the paper�s main conclusion. I do
not see the point in using that chronology, as it represents the average
of three chronologies that have very little in common.
*6.* Page 9. Line 17. �lower than� instead of �lower that�.
* Briffa, K.R., Jones, P.D., Bartholin, T.S., Eckstein, D.,
Schweingruber, F.H., Karlen, W., Zetterberg, P., & Eronen, M.
(1992) Fennoscandian summers from AD-500 - Temperature-changes on
short and long timescales. Climate Dynamics, 7, 111-119.
* Briffa, K.R., Schweingruber, F.H., Jones, P.D., Osborn, T.J.,
Shiyatov, S.G., & Vaganov, E.A. (1998) Reduced sensitivity of
recent tree-growth to temperature at high northern latitudes.
Nature, 391, 678-682.
� Erlandsson, S. (1936) Dendrochronological studies. Report 23. Uppsala,
Sweden. Stockholms H�gskolas Geokronological Institute.
� Fritts, H. (1976) Tree rings and climate. London: Academic Press 567 pp.
� Polyakov, I. Et al. (2002) Observationally based assessment of polar
amplification of global waring. Geophysical Research Letters 29(18):
1878. doi 10.1029/2001GL011111
� Serreze, M. And J.A. Francis. (2006) The Arctic Amplification Debate.
Climatic Change 76: 241-264.
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