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| Titel |
A European network analysis of oxygen isotopes in tree-rings: Concept and first results |
| VerfasserIn |
Kerstin Treydte, Neil Loader |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250045289
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| Zusammenfassung |
| Oxygen isotopes in tree rings are seen as a powerful tool for the reconstruction of past
atmospheric conditions such as the isotopic composition of precipitation, air temperature,
precipitation amount, relative air humidity, or even atmospheric circulation patterns. There
exist, however, still uncertainties regarding the spatial and temporal stability of
the climate signal. These uncertainties arise from the complex interplay between
signals carried in the source water taken up by the roots and those produced by
evaporative enrichment and (post-) photosynthetic processes at the leaf level and during
downstream metabolism. Besides highly resolved physiological process studies, large data
sets of broad ecological, spatial and temporal range are requested to get the best
estimate under which environmental conditions the climatic signal in tree-ring δ18O is
maximized.
Here we present the currently largest and best replicated tree-ring δ18O network
with 35 European sites ranging from Fennoscandia to the Mediterranean region.
Tree-ring δ18O chronologies from four genera (Quercus, Abies, Cedrus, Pinus)
were included in the analysis. The sampling design considered both, ecologically
extreme sites at the northern and alpine treeline with temperature mainly controlling
tree growth, but also temperate sites where mixed climate signals are recorded in
‘traditional’ growth parameters (ring width and maximum late wood density). All
chronologies are annually resolved and fully cover the 20th century, seventeen
chronologies reach 350 years back in time and at least eight chronologies cover the last
1000 years. We will discuss results from (i) signal strength analyses within the
networks, (ii) spatial network analyses and (iii) calibration of isotopic parameters with
climatic variables such as temperature, precipitation and drought, but also with
indicators of atmospheric circulation patterns. We will detail common variance
within European sub-regions and emphasise the reconstruction potential of annually
resolved δ18O from tree rings with a special focus on variation in European air mass
trajectories. |
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