Sunday, June 17, 2012

5270.txt

date: Tue, 4 Jul 2000 10:24:01 +0700
from: "Sukachev Forest Institute" <instituteatXYZxyzest.akadem.ru>
subject: from Prof.Vaganov
to: "Briffa Keith" <K.BriffaatXYZxyz.ac.uk>

Dear Keith
Draft of paper : Briffa K.R. et al. <Tree-ring width and density data around the
Northern
Hemisphere: part 1, local and regional climate signal>
I have no significant remarks over this rich of statistical analysis and complicated
paper. Only one
short note to page 7-8 where in first paragraph telling about weaker TRW climatic signal.
There are
some earlier publications (for example, Hughes et al, 1999) where the highest correlation
(0,84)
between TRW and temperature is shown. The weakness, probably, related to heterogeneity of
sites
(northern timberline and more southern) for large sectors you used and shifting the highest
response to
earlier summer (spring) month towards to south. TRW is highly correlated (R=0,97-99) to
tracheid
production, and in high latitudes the most of tracheids are produced by cambial zone in
first part of a
season, so mainly response to the starting date of beginning of a season (Vaganov,
Shashkin, 2000).
Towards to the south, the starting dates are shifting to early date - it is obvious.



Draft of paper: Briffa et al. <Low-frequency temperature variations from a northern
tree-ring-density
network> (sorry, too many formal statistics for me).
Only some minor notes could be made.
1. Third paragraph in part 2 (page 5). Concerning Fig.3. - what is the differences between
thin and
dashed smoothed lines in individual curves (one is age, another is?). Maybe indicate it in
text rather
in figure captions.
2. Last paragraph in part 3. You may mentioned the similar results about warm 15-th and
coolest late
17-th centuries which are shown in temperature reconstruction based on supra-long Taymir
chronology (Naurzbaev, Vaganov, 2000).
3. Last paragraph in part 4. The main similar cycles were revealed in analysis of Taymir
two-millennia
chronology (ibid).



There are some relevant references (only ours):
1. Vaganov E.A., Shiyatov S.G., Mazepa V.S. Dendroclimatic Study in Ural-Siberian
Subarctic.
Novosibirsk, Nauka, 1996, - 246 pp. (in Russ.).
Annual maps of June-July temperature anomalies over Siberian Subarctic were
constructed
based on 61 local tree-ring chronologies. There is an increasing of frequency of warm
summers for the
whole Siberian Subarctic in 20-th century.



2. Vaganov E.A., Shiyatov S.G., Hantemirov R.M., Naurzbaev M.M. Summer temperature
variations
in high latitudes of Northern Hemisphere during last 1,5 millennia: a comparison analysis
of tree-ring
and ice core data. Doklady AN, 1998, 338(5): 681-684 (in Russ. and Engl.).
Coincidence of long-term summer temperature changes in different regions of
Siberian Subarctic
during last 1,5 thousand years is shown. These changes agree well with Greenland's ice core
data.



3. Vaganov E.A., Hughes M.K. Tree rings and global carbon cycle. Problems of Ecological
Monitoring and Ecosystem Modelling, 2000, 17: 36-48 (in Engl.).
A review of application of various tree-ring data (width, density, fire scars,
isotopic ratio etc.) to
evaluate of certain parameters of carbon cycle in forest ecosystems.



4. Naurzbaev M.M., Vaganov E.A. Variations of early summer and annual temperature in the
East
Taymir and Putoran over last two millennia inferred from tree-rings. J.Geophy.Res., 2000,
105(6):
7317-7327 (in Engl.).
Reconstructed temperature variations agree well with other indirect proxy data and
reveal that
warmth of Medieval Warm Period is closely to warmth in last century. Some cyclic components
are
significantly exist in temperature variations: double secular (around 180 years), secular
(78-90 years)
and intrasecular (44, 28, 11 and 6,7-6,9 years). Long coolest periods were in the end of 13
century and
in 16-17 centuries.



5. Vaganov E.A., Briffa K.R., Naurzbaev M.M., Schweingruber F.H., Shiyatov S.G., Shishov
V.V.
Long-term temperature changes in Arctic region. Doklady AN, 2000, (accepted) (in Russ. and
Engl.).
Similarity of long-term summer temperature changes in high latitudes of Northern
America and
Asia over last 600 years, and significant correlation of its variations to volcanic sulfur
components
(negative) and solar irradiation (positive). Some disagreement between two large sector of
Arctic
region revealed for cool period in 19-th century: in Asian sector cool period occur earlier
than in North
America and Greenland.



6. Vaganov E.A., Shashkin A.V. Tree-ring Growth and Structure in Conifers. Novosibirsk,
Nauka,
2000, - 238 pp. (will be published in September) (in Russ.).



Thanks, Gene.

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