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| Titel |
Exploring the climatic impact of the continental vegetation on the Mezosoic atmospheric CO2 and climate history |
| VerfasserIn |
Y. Donnadieu, Y. Godderis, N. Bouttes |
| 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. 1 ; Nr. 5, no. 1 (2009-03-17), S.85-96 |
| Datensatznummer |
250002248
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| Publikation (Nr.) |
 copernicus.org/cp-5-85-2009.pdf |
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| Zusammenfassung |
| In this contribution, we continue our exploration of the factors
defining the Mesozoic climatic history. We improve the Earth system model
GEOCLIM designed for long term climate and geochemical reconstructions by
adding the explicit calculation of the biome dynamics using the LPJ model.
The coupled GEOCLIM-LPJ model thus allows the simultaneous calculation of
the climate with a 2-D spatial resolution, the coeval atmospheric
CO2, and the continental biome distribution. We found that
accounting for the climatic role of the continental vegetation dynamics
(albedo change, water cycle and surface roughness modulations) strongly
affects the reconstructed geological climate. Indeed the calculated partial
pressure of atmospheric CO2 over the Mesozoic is twice the
value calculated when assuming a uniform constant vegetation. This increase
in CO2 is triggered by a global cooling of the continents,
itself triggered by a general increase in continental albedo owing to the
development of desertic surfaces. This cooling reduces the CO2
consumption through silicate weathering, and hence results in a compensating
increase in the atmospheric CO2 pressure. This study
demonstrates that the impact of land plants on climate and hence on
atmospheric CO2 is as important as their geochemical effect
through the enhancement of chemical weathering of the continental surface.
Our GEOCLIM-LPJ simulations also define a climatic baseline for the Mesozoic,
around which exceptionally cool and warm events can be identified. |
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