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| Titel |
Global observations of glyoxal columns from OMI/Aura and GOME-2/Metop-A sensors and comparison with multi-year simulations by the IMAGES model |
| VerfasserIn |
Christophe Lerot, Trissevgeni Stavrakou, Francois Hendrick, Isabelle De Smedt, Jean-Francois Müller, Rainer Volkamer, Michel Van Roozendael |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250109317
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| Publikation (Nr.) |
 EGU/EGU2015-9219.pdf |
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| Zusammenfassung |
| Volatile organic compounds (VOCs) originating from both natural and human activities play
a key role in air quality. Information on their atmospheric concentrations can be derived using
remote sensing techniques for a limited number of species, including formaldehyde (HCHO)
and glyoxal (CHOCHO). The latter is mostly produced in the atmosphere as an intermediate
product in the oxidation of other non-methane VOCs. It is also directly emitted from fire
events and combustion processes. Owing to its short lifetime, elevated glyoxal concentrations
are observed near emission sources. Measurements of atmospheric glyoxal concentrations
therefore provide quantitative information on the different types of VOC emission and
can help to better assess the quality of current inventories. In addition, glyoxal
is also known to significantly contribute to the total budget of secondary organic
aerosols.
Global observations of glyoxal columns have been realized from different space-borne
spectrometers using the well-known DOAS retrieval technique. In the past, we
developed an algorithm to retrieve glyoxal columns from spectra measured by the
GOME-2 instrument aboard METOP-A (Lerot et al., 2010). Specificities of this
algorithm were an original two-step approach in the DOAS fit to minimize the impact of
spectral interferences with the liquid water absorption as well as the use of a priori
information from the Chemical Transport Model IMAGES in the air mass factor
calculation.
In this work, we present the adaptation of this algorithm to the OMI sensor on the AURA
platform. The time series of glyoxal columns derived from OMI and GOME-2 are compared
in different parts of the world and a high level of consistency is found. The OMI glyoxal data
product is found to be very stable over the entire duration of the mission, in contrast to the
GOME-2 product which is affected by instrumental degradation. We present validation
results using several years of MAX-DOAS glyoxal measurements successively performed in
Beijing and Xianghe, China, since 2008. Also, comparisons of the satellite data sets
with simulations by the IMAGES chemistry transport model show generally good
correlation. Sensitivity tests on the VOC emissions used in the model will also be
discussed.
Lerot, C., Stavrakou, T., De Smedt, I., Müller, J.-F., and Van Roozendael, M.: Glyoxal
vertical columns from GOME-2 backscattered light measurements and comparisons with a
global model, Atmos. Chem. Phys., 10, 12059-12072, doi:10.5194/acp-10-12059-2010,
2010. |
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