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| Titel |
Impacts of East Mediterranean megacity emissions on air quality |
| VerfasserIn |
U. Im, M. Kanakidou |
| 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 ; 12, no. 14 ; Nr. 12, no. 14 (2012-07-23), S.6335-6355 |
| Datensatznummer |
250011331
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| Publikation (Nr.) |
 copernicus.org/acp-12-6335-2012.pdf |
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| Zusammenfassung |
Megacities are large urban agglomerations with intensive anthropogenic
emissions that have significant impacts on local and regional air quality.
In the present mesoscale modeling study, the impacts of anthropogenic
emissions from the Greater Istanbul Area (GIA) and the Greater Athens Area
(GAA) on the air quality in GIA, GAA and the entire East Mediterranean are
quantified for typical wintertime (December 2008) and summertime (July 2008)
conditions. They are compared to those of the regional anthropogenic and
biogenic emissions that are also calculated. Finally, the efficiency of
potential country-based emissions mitigation in improving air quality is
investigated.
The results show that relative contributions from both cities to surface
ozone (O3) and aerosol levels in the cities' extended areas are
generally higher in winter than in summer. Anthropogenic emissions from GIA
depress surface O3 in the GIA by ~ 60% in winter and
~ 20% in summer while those from GAA reduce the surface
O3 in the GAA by 30% in winter and by 8% in summer. GIA and GAA
anthropogenic emissions contribute to the fine particulate matter
(PM2.5) levels inside the cities themselves by up to 75% in winter
and by 50% (GIA) and ~ 40% (GAA), in summer. GIA
anthropogenic emissions have larger impacts on the domain-mean surface
O3 (up to 1%) and PM2.5 (4%) levels compared to GAA
anthropogenic emissions (<1% for O3 and ≤2% for
PM2.5) in both seasons. Impacts of regional anthropogenic emissions on
the domain-mean surface pollutant levels (up to 17% for summertime
O3 and 52% for wintertime fine particulate matter, PM2.5) are
much higher than those from Istanbul and Athens together (~ 1% for
O3 and ~ 6% for PM2.5, respectively).
Regional biogenic emissions are found to limit the production of secondary
inorganic aerosol species in summer up to 13% (non-sea-salt sulfate
(nss-SO42−) in rural Athens) due to their impact on oxidant levels
while they have negligible impact in winter.
Finally, the responses to country-based anthropogenic emission mitigation
scenarios inside the studied region show increases in O3 mixing ratios
in the urban areas of GIA and GAA, higher in winter (~ 13%
for GIA and 2% for GAA) than in summer (~ 7% for GIA and
<1% for GAA). On the opposite PM2.5 concentrations decrease
by up to 30% in GIA and by 20% in GAA with the highest improvements
computed for winter. The emission reduction strategy also leads to
domain-wide decreases in most primary pollutants like carbon monoxide (CO)
or nitrogen oxides (NOx) for both seasons. The results show the
importance of long range transport of pollutants for the air quality in the
East Mediterranean. Thus, improvements of air quality in the East
Mediterranean require coordinated efforts inside the region and beyond. |
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