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| Titel |
Spatial distribution of δ¹⁴CO2 across Eurasia: measurements from the TROICA-8 expedition |
| VerfasserIn |
J. C. Turnbull, J. B. Miller, S. J. Lehman, D. Hurst, W. Peters, P. P. Tans, J. Southon, S. A. Montzka, J. W. Elkins, D. J. Mondeel, P. A. Romashkin, N. Elansky, A. Skorokhod |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 1 ; Nr. 9, no. 1 (2009-01-12), S.175-187 |
| Datensatznummer |
250006638
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| Publikation (Nr.) |
 copernicus.org/acp-9-175-2009.pdf |
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| Zusammenfassung |
Because fossil fuel derived CO2 is the only source of atmospheric
CO2 that is devoid of 14C, atmospheric measurements of Δ14CO2
can be used to constrain fossil fuel emission estimates at
local and regional scales. However, at the continental scale, uncertainties
in atmospheric transport and other sources of variability in Δ14CO2
may influence the fossil fuel detection capability. We
present a set of Δ14CO2 observations from the train-based
TROICA-8 expedition across Eurasia in March–April 2004. Local perturbations
in Δ14CO2 are caused by easily identifiable sources from
nuclear reactors and localized pollution events. The remaining data show an
increase in Δ14CO2 from Western Russia (40° E) to
Eastern Siberia (120° E), consistent with depletion in 14CO2
caused by fossil fuel CO2 emissions in heavily populated Europe, and
gradual dispersion of the fossil fuel plume across Northern Asia.
Other trace gas species which may be correlated with fossil fuel CO2
emissions, including carbon monoxide, sulphur hexafluoride, and
perchloroethylene, were also measured and the results compared with the
Δ14CO2 measurements. The sulphur hexafluoride longitudinal
gradient is not significant relative to the measurement uncertainty. Carbon
monoxide and perchloroethylene show large-scale trends of enriched values in
Western Russia and decreasing values in Eastern Siberia, consistent with
fossil fuel emissions, but exhibit significant spatial variability,
especially near their primary sources in Western Russia.
The clean air Δ14CO2 observations are compared with
simulated spatial gradients from the TM5 atmospheric transport model. We
show that the change in Δ14CO2 across the TROICA transect
is due almost entirely to emissions of fossil fuel CO2, but that the
magnitude of this Δ14CO2 gradient is relatively
insensitive to modest uncertainties in the fossil fuel flux. In contrast,
the Δ14CO2 gradient is more sensitive to the modeled
representation of vertical mixing, suggesting that Δ14CO2
may be a useful tracer for training mixing in atmospheric transport models. |
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