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| Titel |
Summer ammonia measurements in a densely populated Mediterranean city |
| VerfasserIn |
M. Pandolfi, F. Amato, C. Reche, A. Alastuey, R. P. Otjes, M. J. Blom, X. Querol |
| 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. 16 ; Nr. 12, no. 16 (2012-08-20), S.7557-7575 |
| Datensatznummer |
250011403
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| Publikation (Nr.) |
 copernicus.org/acp-12-7557-2012.pdf |
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| Zusammenfassung |
| Real-time measurements of ambient concentrations of gas-phase ammonia
(NH3) were performed in Barcelona (NE Spain) in summer between May and
September 2011. Two measurement sites were selected: one in an urban
background traffic-influenced area (UB) and the other in the historical city
centre (CC). Levels of NH3 were higher at CC (5.6 ± 2.1 μg m−3
or 7.5 ± 2.8 ppbv) compared with UB (2.2 ± 1.0 μg m−3
or 2.9 ± 1.3 ppbv). This difference is attributed to the
contribution from non-traffic sources such as waste containers, sewage
systems, humans and open markets more dense in the densely populated
historical city centre. Under high temperatures in summer these sources had
the potential to increase the ambient levels of NH3 well above the
urban-background-traffic-influenced UB measurement station. Measurements
were used to assess major local emissions, sinks and diurnal evolution of
NH3. The measured levels of NH3, especially high in the old city,
may contribute to the high mean annual concentrations of secondary sulfate
and nitrate measured in Barcelona compared with other cities in Spain
affected by high traffic intensity. Ancillary measurements, including
PM10, PM2.5, PM1 levels (Particulate Matter with aerodynamic
diameter smaller than 10 μm, 2.5 μm, and 1 μm), gases and
black carbon concentrations and meteorological data, were performed during
the measurement campaign. The analysis of specific periods (3 special cases)
during the campaign revealed that road traffic was a significant source of
NH3. However, its effect was more evident at UB compared with CC where
it was masked given the high levels of NH3 from non-traffic sources
measured in the old city. The relationship between SO42− daily
concentrations and gas-fraction ammonia (NH3/(NH3 + NH4+))
revealed that the gas-to-particle phase partitioning (volatilization or
ammonium salts formation) also played an important role in the evolution of
NH3 concentration in summer in Barcelona. |
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