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| Titel |
Lessons learnt from the first EMEP intensive measurement periods |
| VerfasserIn |
W. Aas, S. Tsyro, E. Bieber, R. Bergstrom, D. Ceburnis, T. Ellermann, H. Fagerli, M. Frölich, R. Gehrig, U. Makkonen, E. Nemitz, R. Otjes, N. Pérez, C. Perrino, A. S. H. Prévôt, J.-P. Putaud, D. Simpson, G. Spindler, M. Vana, K. E. Yttri |
| 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. 17 ; Nr. 12, no. 17 (2012-09-10), S.8073-8094 |
| Datensatznummer |
250011435
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| Publikation (Nr.) |
 copernicus.org/acp-12-8073-2012.pdf |
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| Zusammenfassung |
The first EMEP intensive measurement periods were held in June 2006 and
January 2007. The measurements aimed to characterize the aerosol chemical
compositions, including the gas/aerosol partitioning of inorganic compounds.
The measurement program during these periods included daily or hourly
measurements of the secondary inorganic components, with additional
measurements of elemental- and organic carbon (EC and OC) and mineral dust
in PM1, PM2.5 and PM10. These measurements have provided
extended knowledge regarding the composition of particulate matter and the
temporal and spatial variability of PM, as well as an extended database for
the assessment of chemical transport models. This paper summarise the first
experiences of making use of measurements from the first EMEP intensive
measurement periods along with EMEP model results from the updated model
version to characterise aerosol composition. We investigated how the PM
chemical composition varies between the summer and the winter month and
geographically.
The observation and model data are in general agreement regarding the main
features of PM10 and PM2.5 composition and the relative
contribution of different components, though the EMEP model tends to give
slightly lower estimates of PM10 and PM2.5 compared to
measurements. The intensive measurement data has identified areas where
improvements are needed. Hourly concurrent measurements of gaseous and
particulate components for the first time facilitated testing of modelled
diurnal variability of the gas/aerosol partitioning of nitrogen species. In
general, the modelled diurnal cycles of nitrate and ammonium aerosols are in
fair agreement with the measurements, but the diurnal variability of ammonia
is not well captured. The largest differences between model and observations
of aerosol mass are seen in Italy during winter, which to a large extent may
be explained by an underestimation of residential wood burning sources. It
should be noted that both primary and secondary OC has been included in the
calculations for the first time, showing promising results. Mineral dust is
important, especially in southern Europe, and the model seems to capture the
dust episodes well. The lack of measurements of mineral dust hampers the
possibility for model evaluation for this highly uncertain PM component.
There are also lessons learnt regarding improved measurements for future
intensive periods. There is a need for increased comparability between the
measurements at different sites. For the nitrogen compounds it is clear that
more measurements using artefact free methods based on continuous
measurement methods and/or denuders are needed. For EC/OC, a reference
methodology (both in field and laboratory) was lacking during these periods
giving problems with comparability, though measurement protocols have
recently been established and these should be followed by the Parties to the
EMEP Protocol. For measurements with no defined protocols, it might be a
good solution to use centralised laboratories to ensure comparability across
the network. To cope with the introduction of these new measurements, new
reporting guidelines have been developed to ensure that all proper
information about the methodologies and data quality is given. |
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