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| Titel |
High resolution climate and vegetation simulations of the Late Pliocene, a model-data comparison over western Europe and the Mediterranean region |
| VerfasserIn |
A. Jost, S. Fauquette, M. Kageyama, G. Krinner, G. Ramstein, J.-P. Suc, S. Violette |
| 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 ; 5, no. 4 ; Nr. 5, no. 4 (2009-10-12), S.585-606 |
| Datensatznummer |
250002690
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| Publikation (Nr.) |
 copernicus.org/cp-5-585-2009.pdf |
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| Zusammenfassung |
Here we perform a detailed comparison between climate model results
and climate reconstructions in western Europe and the Mediterranean
area for the mid-Piacenzian warm interval (ca 3 Myr ago) of the
Late Pliocene epoch.
This region is particularly well suited for such a comparison as
several quantitative climate estimates from local pollen records
are available. They show evidence for temperatures significantly
warmer than today over the whole area, mean annual precipitation
higher in northwestern Europe and equivalent to modern values in its
southwestern part. To improve our comparison, we have performed high
resolution simulations of the mid-Piacenzian climate using the LMDz
atmospheric general circulation model (AGCM) with a stretched grid
which allows a finer resolution over Europe. In a first step, we
applied the PRISM2 (Pliocene Research, Interpretation, and Synoptic
Mapping) boundary conditions except that we used modern terrestrial
vegetation. Second, we simulated the vegetation for this period by
forcing the ORCHIDEE (Organizing Carbon and Hydrology in Dynamic
Ecosystems) dynamic global vegetation model (DGVM) with the climatic
outputs from the AGCM. We then supplied this simulated terrestrial
vegetation cover as an additional boundary condition in a second AGCM
run. This gives us the opportunity to investigate the model's
sensitivity to the simulated vegetation changes in a global warming
context.
Model results and data show a great consistency for mean annual
temperatures, indicating increases by up to 4°C in the
study area, and some disparities, in particular in the northern
Mediterranean sector, as regards winter and summer temperatures.
Similar continental mean annual precipitation and
moisture patterns are predicted by the model, which broadly
underestimates the wetter conditions indicated by the data in
northwestern Europe.
The biogeophysical effects due to the changes in vegetation simulated
by ORCHIDEE are weak, both in terms of the hydrological cycle and of
the temperatures, at the regional scale of the European and
Mediterranean mid-latitudes. In particular, they do not contribute to
improve the model-data comparison. Their main influence concerns
seasonal temperatures, with a decrease of the temperatures of the
warmest month, and an overall reduction of the intensity of the
continental hydrological cycle. |
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