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| Titel |
Joint CO2 state and flux estimation with the 4D-Var system EURAD-IM |
| VerfasserIn |
Johannes Klimpt, Hendrik Elbern |
| 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 |
250133263
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| Publikation (Nr.) |
 EGU/EGU2016-13852.pdf |
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| Zusammenfassung |
| Atmospheric CO2 inversion studies seek to improve CO2 surface-atmosphere fluxes
with the usage of adjoint transport models and CO2 concentration measurements.
Terrestrial CO2 fluxes –anthropogenic emissions, photosynthesis, and respiration–
bear large spatial and temporal variability and are highly uncertain. Additionally
to the high uncertainty of the three CO2 fluxes itself, regional inversion studies
suffer from uncertainty of the boundary layer height and atmospheric transport
especially during night, leading to uncertainty of atmospheric CO2 mixing ratios
during sunrise. This study assesses the potential of the 4-dimensional variational
(4D-Var) method to estimate CO2 fluxes and atmospheric CO2 concentrations jointly at
each grid cell on a regional scale. Identical twin experiments are executed with the
nested EURopean Air pollution Dispersion-Inverse Model (EURAD-IM) with 5 km
resolution in Central Europe with synthetic half hourly measurements from eleven
concentration towers. The assimilation window is chosen to start from sunrise for
12 hours. We find that joint estimation of CO2 fluxes and initial states requires a
more careful balance of the background error covariance matrices but enables a
more detailed analysis of atmospheric CO2 and the surface-atmosphere fluxes. |
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