Wednesday, December 7, 2011

0962724639.txt

From: stepan <stepan@ipae.uran.ru>
To: k.briffa@uea.ac.uk
Subject: Manuskript of papes
Date: Tue, 4 Jul 2000 11:30:39 +0600
Reply-to: stepan <stepan@ipae.uran.ru>
Cc: t.osborn@uea.ac.uk

Dear Keith and Tim,

Thank you for the papers which I have received some days ago. They
produced an impression on me. It is really a big job. I do not have
time now to evaluate in details the results obtained. I want to make
two remarks only.

First, I think, that the method of standardisation is very
interesting, but it is disputable for the regions and sites where
trees grow under extreme climatic conditions, for example at the polar
timberline in Siberia. In such conditions the shape of age curve and
the age of maximum growth are very changeable in different trees
growing at the same site. It will be very interesting if you can
present the age curve obtained for one such site, for example for the
North Taymir Peninsula.

Second, I do not agree that in the northern Siberia the 15th century
summers were warmer than those observed in the 20th century, at least
in the Western and Middle Siberia. May be it is a result of
stundartisation?

We suggest to inscibe in list of references the next papers:

1. Vaganov E.A., Shiyatov S.G., Mazepa V.S. Dendroclimatic study in
Ural-Siberian Subarctic. - Novosibirsk "Nauka", Siberian
Publishing Firm RAS, 1996. - 246 p. (in Russian).

2. Mazepa V.S. Influence of Precipitations on Tree-Ring Growth of
Coniferous in Subarctic Regions of Eurasia //Lesovedenie, No. 6,
1999. - P.14-21. (in Russian).

Abstract. Influence of precipitation on tree-ring variability of coniferous
trees in Subarctic regions of Eurasia has been shown. Depending
on the region, significant ecological factor for tree growth are
precipitation of autumn-winter, winter-spring and summer periods.
Ecological explanation of such influence has been given. On the
base of relationships between tree-rings and rainfall the
reconstructions of precipitation in different regions of
Subarctic for last 200 years have been developed.

3. Mazepa V.S. Spatial Reconstruction of Summer Air Temperature in the North of
the West Siberia since 1690 on the base of Tree-Ring Data.
//Siberian ecological journal, No. 2, 1999. - P.175-183. (in Russian).

Abstract. Opportunity of annual reconstruction of summer thermal
conditions from Polar Urals (64-68�N, 64-68�E) up to Yenisei
River (66-70�N, 86-89�E) is caused by high and sufficiently
stable relationship between coniferous tree growth (Larix
sibirica, Picea obovata) and corresponding climatic factors.
Percent variance in tree-ring chronologies explained by climate
(June-July temperature) in this extreme for growth of trees area
reaches 50%. Spatial reconstruction of air summer temperature on
the base of point reconstruction for 11 corresponding
meteostations has been developed. Analysis of reconstructed
temperatures has shown their significant changes for last 300
years. The most strong fall of temperatures was observed in XIX
century, but rise in temperature was observed in XVIII and XX
centuries.

4. Mazepa V.S. Dendroclimatic reconstructing air summer temperatures since 1690
in subarctic regions of siberia. //Problems of ecological
monitoring and ecosystem modelling, Volume XVII. - St.Petersburg
Gidrometeoizdat, 2000. - P.170-187. (in Russian).

Abstract. The further development of many-year dendroclimatic
study carried out in subarctic regions of Siberia and on the
polar timberline, is given in this paper. Climatic factors
determining the year-to-year and many-yeared tree-ring width
variability were revealed, using multiple regression models. The
spatial year-to-year reconstruction of air summer temperatures
was made on the base of available dendroclimatic network. The
reliability of spatial summer temperatures reconstruction in the
boreal zone of the Urals and Siberia was evaluated. The temporal
dendroclimatic zoning of the area investigated was carried out
according to the chronology similarity. The regional border
changes, depending on warm and cold periods, were shown. Five
regional chronologies showing the nature of summer months thermic
regime variability were developed. Extremely cold and warm
periods were revealed. The coldest periods are: the first half of
XVII and XIX centuries. The warmest periods are: the second half
of XVII, XVIII and middle of XX centuries.

To-day R. Hantemirov and A. Surkov will go to the Yamal Peninsula for
subfossil wood collecting. I and V. Mazepa will go to the Polar Ural
Mountains in some days.

Best regards,
Stepan mailto:stepan@ipae.uran.ru


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