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| Titel |
Estimating impact of different GOSAT CH4 retrievals and OH concentrations on CH4 flux inversions |
| VerfasserIn |
Ilya Stanevich, Kimberly Strong, Dylan Jones, Feng Deng, Kevin Wecht, André Butz, Robert Parker, Paul Wennberg, Debra Wunch, Coleen Roehl |
| 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 |
250130939
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| Publikation (Nr.) |
 EGU/EGU2016-11270.pdf |
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| Zusammenfassung |
| Identifying global CH4 sources and their emissions is important for understanding the
processes that govern the increase of CH4 in the atmosphere. Differences between satellite
retrievals used in inversion analyses can provide varying estimates of global CH4 emissions.
Although the lifetime of CH4 is about 10 years, discrepancies in the distribution of the
hydroxyl radical (OH), will also influence optimized CH4 emissions. Inversion analyses
using the GEOS-Chem four-dimensional variational (4D-Var) data assimilation system are
performed for the period from January to December 2010 to assess the impact of the GOSAT
CH4 Full Physics and Proxy retrievals and discrepancies in OH fields in GEOS-Chem on
regional CH4 emission estimates. We compare the performance of the retrievals and show the
sensitivity of the inferred emissions to the spatial coverage of the retrievals. We also
show that the seasonality of the emission estimates is sensitive to the imposed OH
distribution. We find that neither retrieval product corrects well for regional biases
between measurements and the optimized CH4 fields, particularly, in winter months at
high latitudes with sparse retrieval coverage. The latter highlights the challenge of
quantifying CH4 emissions at subcontinental scales with the current observing network. |
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