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Titel |
Impact of an extremely large magnitude volcanic eruption on the global climate and carbon cycle estimated from ensemble Earth System Model simulations |
VerfasserIn |
J. Segschneider, A. Beitsch, C. Timmreck, V. Brovkin, T. Ilyina, J. Jungclaus, S. J. Lorenz, K. D. Six, D. Zanchettin |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 10, no. 2 ; Nr. 10, no. 2 (2013-02-01), S.669-687 |
Datensatznummer |
250017495
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Publikation (Nr.) |
copernicus.org/bg-10-669-2013.pdf |
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Zusammenfassung |
The response of the global climate-carbon cycle system to an extremely large Northern Hemisphere
mid-latitude volcanic eruption is investigated using ensemble integrations with the comprehensive
Earth System Model MPI-ESM. The model includes dynamical compartments of the atmosphere and ocean and
interactive modules of the terrestrial biosphere as well as ocean biogeochemistry. The MPI-ESM was
forced with anomalies of aerosol optical depth and effective radius of aerosol particles corresponding to
a super eruption of the Yellowstone volcanic system. The model experiment consists of an ensemble of
fifteen model integrations that are started at different pre-ENSO states of a control experiment and
run for 200 years after the volcanic eruption. The climate response to the volcanic eruption is a
maximum global monthly mean surface air temperature cooling of 3.8 K for the ensemble mean and from
3.3 K to 4.3 K for individual ensemble members. Atmospheric pCO2 decreases by a maximum of 5 ppm for
the ensemble mean and by 3 ppm to 7 ppm for individual ensemble members approximately 6 years after
the eruption. The atmospheric carbon content only very slowly returns to near pre-eruption level at year
200 after the eruption. The ocean takes up carbon shortly after the eruption in response to the cooling,
changed wind fields and ice cover. This physics-driven uptake is weakly counteracted by a reduction of
the biological export production mainly in the tropical Pacific. The land vegetation pool shows a decrease
by 4 GtC due to reduced short-wave radiation that has not been present in a smaller scale eruption. The
gain of the soil carbon pool determines the amplitude of the CO2 perturbation and the long-term
behaviour of the overall system: an initial gain caused by reduced soil respiration is followed by
a rather slow return towards pre-eruption levels. During this phase, the ocean compensates partly for
the reduced atmospheric carbon content in response to the land's gain. In summary, we find that the
volcanic eruption has long-lasting effects on the carbon cycle: After 200 years, the ocean and the
land carbon pools are still different from the pre-eruption state by 3 GtC and 4 GtC, respectively,
and the land carbon pools (vegetation and soil) show some long-lasting local anomalies that are only
partly visible in the global signal. |
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