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| Titel |
GOME-2 observations of oxygenated VOCs: what can we learn from the ratio glyoxal to formaldehyde on a global scale? |
| VerfasserIn |
M. Vrekoussis, F. Wittrock, A. Richter, J. P. Burrows |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 21 ; Nr. 10, no. 21 (2010-11-01), S.10145-10160 |
| Datensatznummer |
250008859
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| Publikation (Nr.) |
 copernicus.org/acp-10-10145-2010.pdf |
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| Zusammenfassung |
| Collocated data sets of glyoxal (CHO.CHO) and formaldehyde (HCHO) were
retrieved for the first time from measurements of the Global Ozone
Monitoring Experiment-2 (GOME-2) during the first two years of operation in
2007 and 2008. Both oxygenated Volatile Organic Compounds, OVOC, are key
intermediate species produced during the oxidation of precursor
hydrocarbons. Their short lifetime of a few hours in the lower troposphere
links them to emission sources and makes them useful tracers of
photochemical activity. The global composite maps of GOME-2 HCHO and CHO.CHO
have strong similarities confirming their common atmospheric and/or surface
sources. The highest column amounts of these OVOCs are recorded over regions
with enhance biogenic emissions (e.g. tropical forests in South America,
Africa and Indonesia). Enhanced OVOC values are also present over areas of
anthropogenic activity and biomass burning (e.g. over China, N. America,
Europe and Australia). The ratio of CHO.CHO to HCHO, RGF, has been
used, for the first time on a global scale, to classify the sources
according to biogenic and/or anthropogenic emissions of the precursors;
RGF between 0.040 to 0.060 point to the existence of biogenic emissions
with the highest values being observed at the highest Enhanced Vegetation
Index, EVI. RGFs below 0.040 are indicative of anthropogenic emissions
and associated with high levels of NO2. This decreasing tendency of
RGF with increasing NO2 is also observed when analyzing data for
individual large cities, indicating that it is a common feature. The results
obtained for RGF from GOME-2 data are compared with the findings based
on regional SCIAMACHY observations showing good agreement. This is explained
by the excellent correlation of the global retrieved column amounts of
CHO.CHO and HCHO from the GOME-2 and SCIAMACHY instruments for the period
2007–2008. |
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