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Titel |
Forward modelling of tree-ring width and comparison with a global network of tree-ring chronologies |
VerfasserIn |
P. Breitenmoser, S. Brönnimann, D. Frank |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1814-9324
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Digitales Dokument |
URL |
Erschienen |
In: Climate of the Past ; 10, no. 2 ; Nr. 10, no. 2 (2014-03-11), S.437-449 |
Datensatznummer |
250116931
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Publikation (Nr.) |
copernicus.org/cp-10-437-2014.pdf |
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Zusammenfassung |
We investigate relationships between climate and tree-ring data on a global
scale using the process-based Vaganov–Shashkin Lite (VSL) forward model of
tree-ring width formation. The VSL model requires as inputs only latitude,
monthly mean temperature, and monthly accumulated precipitation. Hence, this
simple, process-based model enables ring-width simulation at any location
where monthly climate records exist. In this study, we analyse the growth
response of simulated tree rings to monthly climate conditions obtained from
the CRU TS3.1 data set back to 1901. Our key aims are (a) to assess the VSL
model performance by examining the relations between simulated and observed
growth at 2287 globally distributed sites, (b) indentify optimal growth
parameters found during the model calibration, and (c) to evaluate the
potential of the VSL model as an observation operator for
data-assimilation-based reconstructions of climate from tree-ring width. The assessment of the
growth-onset threshold temperature of approximately 4–6 °C for
most sites and species using a Bayesian estimation approach complements
other studies on the lower temperature limits where plant growth may be
sustained. Our results suggest that the VSL model skilfully simulates site
level tree-ring series in response to climate forcing for a wide range of
environmental conditions and species. Spatial aggregation of the tree-ring
chronologies to reduce non-climatic noise at the site level yielded notable
improvements in the coherence between modelled and actual growth. The
resulting distinct and coherent patterns of significant relationships
between the aggregated and simulated series further demonstrate the VSL
model's ability to skilfully capture the climatic signal contained in
tree-ring series. Finally, we propose that the VSL model can be used as an
observation operator in data assimilation approaches to reconstruct past
climate. |
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