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| Titel |
Terrestrial carbon sink observed from space: Sensitivity of atmospheric CO2 growth rates and seasonal cycle amplitudes to surface temperature |
| VerfasserIn |
Oliver Schneising, Maximilian Reuter, Michael Buchwitz, Jens Heymann, Heinrich Bovensmann, John P. Burrows |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250091722
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| Publikation (Nr.) |
 EGU/EGU2014-6030.pdf |
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| Zusammenfassung |
| The terrestrial biosphere is currently acting as a net carbon sink on the global scale,
exhibiting significant interannual variability in strength. To reliably predict the future
strength of the land sink and its role in atmospheric CO2 growth, the underlying
biogeochemical processes and their response to a changing climate need to be well
understood. In particular, better knowledge of the impact of key climate variables
such as temperature on the biospheric carbon reservoir is essential. Global satellite
measurements of column-averaged mole fractions of atmospheric CO2, which offer
complementary information to the accurate and precise but inevitably sparse ground-based
measurements, can contribute to determine characteristics of the terrestrial carbon
sink.
It is demonstrated using nearly a decade of SCIAMACHY nadir measurements that years
with higher temperatures during the growing season can be robustly associated with larger
growth rates in atmospheric CO2 and smaller seasonal cycle amplitudes for northern
mid-latitudes. We find linear relationships between warming and CO2 growth as well as
seasonal cycle amplitude at the 98 % significance level. The quantitative estimates of the
corresponding covariations are consistent with those from the CarbonTracker data assimilated
CO2 product, indicating that the temperature dependence of the model surface fluxes is
realistic.
The derived results suggest that the terrestrial carbon sink is less efficient at higher
temperatures during the analysed time period. Unless the biosphere has the ability to adapt its
carbon storage under warming conditions in the longer term, such a temperature response
entails the risk of potential future sink saturation via a positive carbon-climate feedback. |
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