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| Titel |
Influence of the linear-k method on the accuracy and computational efficiency of GOSAT BESD XCO2 retrievals |
| VerfasserIn |
Michael Hilker, Maximilian Reuter, Jens Heymann, Oliver Schneising, Michael Buchwitz, Heinrich Bovensmann, John 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 |
250086950
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| Publikation (Nr.) |
 EGU/EGU2014-896.pdf |
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| Zusammenfassung |
| Carbon dioxide (CO2) is the most important anthropogenic greenhouse gas contributing to
global climate change but there are still large uncertainities of its sources and sinks.
Global measurements of CO2 concentrations from satellites have the potential to
reduce these uncertainities. This however requires to meet challenging accuracy
requirements.
The Bremen Optimal Estimation - DOAS (BESD) retrieval algorithm has been developed
to retrieve column-averaged dry air mole fractions of CO2 (XCO2) from measurements of the
SCIAMACHY instrument onboard ENVISAT. After the end of the ENVISAT mission in
March 2012, TANSO onboard GOSAT is the only satellite instrument with high sensitivity
near the surface. To obtain a consistent global long-term XCO2 data set from these two
instruments, a modified version of the BESD algorithm is also used for the retrieval of XCO2
from GOSAT. BESD requires computational expensive online radiative transfer calculations
with high spectral resolution for an absorbing and scattering atmosphere. Due to higher
spectral resolution of TANSO, approximations used to reduce computation time for
SCIAMACHY retrievals are no longer valid. In order to improve the computational
efficiency, a modified linear-k method is used. Implemented modifications and
first results of a validation with line-by-line based BESD retrievals are presented. |
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