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| Titel |
Impact of anthropogenic emissions from major population centers on global and regional aerosol budgets |
| VerfasserIn |
Daniel Kunkel, Holger Tost, Mark Lawrence |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250078264
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| Zusammenfassung |
| In urban areas, in particular in major population centers (MPCs), anthropogenic pollutants
can dominate over natural emissions and cause severe air quality problems. We used emission
annihilation scenario simulations in the atmospheric chemistry global circulation model
EMAC to study the individual and cumulative impact of four major aerosol species from
MPCs on the global and regional aerosol budgets. Black carbon, particulate organic
matter, sulphur dioxide (SO2), and nitrogen oxides (NOx) were used to represent
emissions of primary aerosols and of precursors gases for secondary aerosols sulphate
and nitrate, respectively. Moreover, feedbacks resulting from changed emissions
on other atmospheric constituents were assessed and the linearity in the burden
changes due to the emission changes was discussed. Aerosol sulphate showed the
strongest decrease in the global budget and also the most widespread changes in
the tropospheric column density, whereas the smallest global decrease with only
local changes was found for particulate organic matter. The maximum reduction
was found around the emission sources and in downwind regions. The primary
emitted aerosols showed almost no feedback on other species. In contrast, many
gas-aerosol equilibria were affected when the SO2 and NOx emissions were reduced.
In the case with the reduced MPC-NOx emissions, many species participating
in the NOx–ozone (O3) chemistry showed a response in their concentrations. In
particular, ozone changed differently in extra-tropical and tropical cities, which is in
accordance with findings of Butler and Lawrence (2009). Moreover, the oxidation
capacity of the atmosphere was changed. The hydroxyl radical concentration changed
similarly to O3, which lead to an increase in the tropospheric carbon monoxide
concentration and to locally greater SO2 concentrations. Changes in the emissions
for black carbon, particulate organic matter, and SO2 resulted in almost linear
responses of the corresponding atmospheric burdens. However, for NOx and the
aerosol nitrate this was only the case during boreal winter, but not during summer
when the (ammonium-)nitrate burden depended not only on the NOx emissions but
also on the ambient temperature and the available sulphuric acid concentration. |
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