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| Titel |
SCIAMACHY WFM-DOAS XCO2: Improvements and comparison with FTS measurements |
| VerfasserIn |
J. Heymann, O. Schneising, M. Buchwitz, M. Reuter, H. Bovensmann, J. P. Burrows |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250058566
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| Zusammenfassung |
| Carbon Dioxide (CO2) is the most important anthropogenic greenhouse gas contributing to
global climate change. Column-averaged dry air mole fractions of CO2 (XCO2) as retrieved
from SCIAMACHY on-board ENVISAT (launch 2002) have the potential to provide
important missing global information on regional CO2 surface fluxes. This however requires
to satisfy challenging accuracy requirements. Here, we present results of an inter-comparison
of seven years (2003 - 2009) of SCIAMACHY XCO2 retrievals obtained with version 2.1
(WFMDv2.1) and an updated version (WFMDv2.2) of the WFM-DOAS retrieval algorithm
with FTS measurements from TCCON sites. An improved cloud filtering method has been
applied to the WFMDv2.2 retrievals because scattering by unaccounted clouds,
especially thin cirrus clouds, is an important error source. The filter is based on a
threshold technique using radiances from the saturated water vapour absorption
band at 1.4 μm which is mostly sensitive to thin clouds. The inter-comparison of
the SCIAMACHY WFM-DOAS XCO2 versions with FTS measurements shows
overall better agreements for WFMDv2.2. These results show that the cloud filtering
method successfully improves the SCIAMACHY WFM-DOAS XCO2 data set. |
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