date: Tue Jun  6 14:30:55 2006
from: Tim Osborn <t.osborn@uea.ac.uk>
subject: Re: HOLIVAR poster session 3
to: "Sonechkin D.M." <dsonech@mecom.ru>

   Thanks!
   Tim
   At 11:15 31/05/2006, you wrote:

     Dear Tim,
     I shall show a new technique of tree-ring-based reconstruction with
     an illustration on the known Tornetrask tree-ring set
     (this research is in collaboration with my colleague Nina Datsenko
     from HydroMeteoCenter of Russia, and with H.grudd and a. Moberg from the Stockholm
     University).
     The essence consists of the use a new index dR(t)*R(t)-Mean(dR(100)*R(100))
     where dR(t) - ring width of the year t, R(t) - the inner radius of this ring,
     Mean(dR(100)*R(100)) - mean value of the product for 100-year old trees
     calculated for consequent time intervals of 200 or 500 years in their length.
     This quantity is a characteristic of general environmental conditions during respective
     time intervals,
     and so it admits to represent lower-frequency responses of trees to varying climatic and
     environmental conditions.
     Note, our index is similar to the know basal area increment index, but it is robust to
     deviations of the stem geometry
     from ideal circle.
     Our index is age-insensitive for mature trees (.100 year old).
     The first of attached reconstruction (they cover more than the latest 2000 y)
     is created with use all mature trees from the Tornetrsk set.
     One can see that the MWP and the Roman warm epoch were warmer then the current climate.
     But one can see some delta-like peaks in the reconstruction by the reasn of poor
     sampling for respective time moments.
     Therefore, the second and third reconstruction are created with use the only cases when
     more than 3 or 5 tree-rings
     exist for a year. All peaks are absent in the third reconstruction, but some gaps exist.
     Green line shown in the third reconstruction represent an estimation of temperature
     variations BP
     published by a Swedish paleoclimatologist Moerner (1976). He used dO18 in sediments of
     the Tingstedetrask lake
     (Gotland).
     One can see the third reconstruction cartch rather well the manycentennial temperature
     variations indeed.
     Dmitry Sonechkin
     Tim Osborn wrote:

     Hi everyone,
     sorry for the mass posting, but as there are so many of you I couldn't send out
     individual requests.
     I have the honor of introducing the poster session for theme 3 (Climate variability in
     the last 2000 years) of the HOLIVAR conference, for which you are all listed as
     presenting posters.
     In my 15 minute slot I will try to mention as many of your posters as possible, or at
     least groupings of those in common themes.
     It would be nice if I could show a figure from many of the posters to induce the
     audience's curiosity so that they go and find out more from you/your poster.  Obviously
     I wouldn't have time to explain anything in detail.
     If you would be willing, then please send me one figure from your poster (JPEG, GIF,
     PNG, PDF etc. including caption) and I will try to include it.
     If you have not yet made your poster, then it does not matter too much if you send a
     figure which is not identical to your final choice for your poster... as I said it is
     just to whet the audience's appetite.
     Best regards
     Tim
     Dr Timothy J Osborn, Academic Fellow
     Climatic Research Unit
     School of Environmental Sciences, University of East Anglia
     Norwich  NR4 7TJ, UK
     e-mail:   t.osborn@uea.ac.uk
     phone:    +44 1603 592089
     fax:      +44 1603 507784
     web:      [1]http://www.cru.uea.ac.uk/~timo/
     sunclock: [2]http://www.cru.uea.ac.uk/~timo/sunclock.htm