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| Titel |
Providing Space-Based Constraints on the Chemical Composition of Aerosols |
| VerfasserIn |
J. P. Veefkind, B. Veihelmann, K. F. Boersma, T. Kurosu, P. F. Levelt |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250025246
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| Zusammenfassung |
| Human activities around the globe cause the emission of gases such as SO2, NOx and VOCs.
In the atmosphere, these gases are transformed to secondary fine mode aerosol particles.
Understanding sources of anthropogenic aerosols and their precursor gases is relevant for
climate change as well as for air quality. To predict how the aerosol load responds on
changing emissions, knowledge of the chemical composition of aerosol particles is
necessary.
Over the last decade, accurate satellite data on aerosol optical thickness (AOT) and
tropospheric columns of NO2, SO2 and formaldehyde (HCHO) have become available. In
this contribution we use AOT from MODIS on the NASA EOS Aqua satellite and NO2, SO2
and HCHO data from OMI on the NASA EOS Aura satellite, which are both part of the
A-Train satellite constellation. Whereas the trace gas tropospheric columns are a direct
measure of the concentration, the AOT is an optical parameter, which is not directly linked to
the physical and chemical properties of the aerosol particles. To establish the link between
the AOT and its precursor gases, we have investigated the spatial correlation of
AOT and the trace gas columns in multi-year averages for different regions and
seasons.
The results show that in regions where the aerosol is dominated by anthropogenic
sources, there is a strong spatial correlation between AOT and tropospheric NO2. HCHO
columns correlated with AOT for biomass burning regions and industrial regions in Asia.
Also strong correlation is observed between AOT and HCHO over the Southeast of
the USA in the summer season, which can be attributed to aerosols from biogenic
sources.
We show that the corresponding slope between the AOT and NO2 varies strongly between
source regions and contains information on the chemical composition of the aerosol particles.
For example, we find that the AOT- NO2 slope is comparable between Northwestern Europe
and the US East coast, but deviates from the slope over Eastern Europe. This difference in
slope can be explained by difference in the sulfate to nitrate ratio of the aerosol
particles. |
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