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| Titel |
Inverse modelling of European CH4 and N2O emissions 2006-2012 using different inverse models and improved atmospheric observations |
| VerfasserIn |
Peter Bergamaschi, Ute Karstens, Ernest Koffi, Marielle Saunois, Timothy Arnold, Alistair Manning, Aki Tsuruta, Antoine Berchet, Alex Vermeulen, Greet Janssens-Maenhout, Samuel Hammer, Ingeborg Levin, Martina Schmidt |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250124916
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| Publikation (Nr.) |
 EGU/EGU2016-4423.pdf |
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| Zusammenfassung |
| We present top-down estimates of European CH4 and N2O emissions for 2006-2012, based
on the new quality controlled and harmonized data set from 18 European atmospheric
monitoring stations generated within the European FP7 project InGOS ("Integrated non-CO2
Greenhouse gas Observing System"). We applied an ensemble of 7 different inverse
models for CH4 (and 4 for N2O), and performed four different inversion experiments,
investigating the impact of different sets of stations and the use of ’a priori’ information on
emissions.
The inverse models infer total CH4 emissions of 28.4 ± 6.4 (2σ) Tg CH4 yr−1 for the
EU-28 for 2006-2012 from the 4 inversion experiments. For comparison, total anthropogenic
CH4 emissions reported to UNFCCC (’bottom-up’, based on statistical data and emissions
factors) amount to only 19.0 - 20.9 Tg CH4 yr−1 for the same period. A potential
explanation for the discrepancy between the ’bottom-up’ and ’top-down’ estimates could
be the contribution of natural sources, such as peatlands, wetlands, and wet soils,
which might have been underestimated in previous analyses. The hypothesis of
significant natural emissions is supported by the finding that the inversions yield
significant seasonal cycles of derived CH4 emissions with maximum in summer,
while anthropogenic CH4 emissions are assumed to have much lower seasonal
variability. Furthermore we investigate potential biases of the flux inversions by
comparing model simulations with regular aircraft profiles at 4 European sites and the
’Infrastructure for Measurement of the European Carbon Cycle (IMECC)’ aircraft
campaign.
For N2O, for which uncertainties of bottom-up inventories are very large - typically on
the order of 100% for the total N2O emissions per country (mainly due to N2O emissions
from agricultural soils) - our results demonstrate that atmospheric measurements and inverse
modelling can significantly reduce the uncertainties. Despite the large uncertainties in the
bottom-up inventories, our estimate of total European N2O emissions (EU-28: 1.41 ± 0.54
(2σ) Tg N2O yr−1) agrees relatively well with reported total anthropogenic N2O emissions
(EU-28: 1.08-1.23 Tg N2O yr−1) and an assumed small contribution from natural soils (∼0.1
Tg N2O yr−1). |
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