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| Titel |
Sensitivity of atmospheric CO2 and climate to explosive volcanic eruptions |
| VerfasserIn |
T. L. Frölicher, F. Joos, C. C. Raible |
| 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 ; 8, no. 8 ; Nr. 8, no. 8 (2011-08-24), S.2317-2339 |
| Datensatznummer |
250006086
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| Publikation (Nr.) |
 copernicus.org/bg-8-2317-2011.pdf |
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| Zusammenfassung |
| Impacts of low-latitude, explosive volcanic eruptions on climate and the
carbon cycle are quantified by forcing a comprehensive, fully coupled carbon
cycle-climate model with pulse-like stratospheric aerosol optical depth
changes. The model represents the radiative and dynamical response of the
climate system to volcanic eruptions and simulates a decrease of global and
regional atmospheric surface temperature, regionally distinct changes in
precipitation, a positive phase of the North Atlantic Oscillation, and a
decrease in atmospheric CO2 after volcanic eruptions. The volcanic-induced
cooling reduces overturning rates in tropical soils, which dominates over
reduced litter input due to soil moisture decrease, resulting in higher land
carbon inventories for several decades. The perturbation in the ocean carbon
inventory changes sign from an initial weak carbon sink to a carbon source.
Positive carbon and negative temperature anomalies in subsurface waters last
up to several decades. The multi-decadal decrease in atmospheric CO2
yields a small additional radiative forcing that amplifies the cooling and
perturbs the Earth System on longer time scales than the atmospheric
residence time of volcanic aerosols. In addition, century-scale global
warming simulations with and without volcanic eruptions over the historical
period show that the ocean integrates volcanic radiative cooling and responds
for different physical and biogeochemical parameters such as steric sea level
or dissolved oxygen. Results from a suite of sensitivity simulations with
different magnitudes of stratospheric aerosol optical depth changes and from
global warming simulations show that the carbon cycle-climate sensitivity
γ, expressed as change in atmospheric CO2 per unit change in global
mean surface temperature, depends on the magnitude and temporal evolution of
the perturbation, and time scale of interest. On decadal time scales, modeled
γ is several times larger for a Pinatubo-like eruption than for the
industrial period and for a high emission, 21st century scenario. |
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