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| Titel |
Influence of meteorology on PM10 trends and variability in Switzerland from 1991 to 2008 |
| VerfasserIn |
I. Barmpadimos, C. Hueglin, J. Keller, S. Henne, A. S. H. Prévôt |
| 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 ; 11, no. 4 ; Nr. 11, no. 4 (2011-02-28), S.1813-1835 |
| Datensatznummer |
250009379
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| Publikation (Nr.) |
 copernicus.org/acp-11-1813-2011.pdf |
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| Zusammenfassung |
| Measurements of airborne particles with aerodynamic diameter of 10 μm
or less (PM10) and meteorological observations are available from 13
stations distributed throughout Switzerland and representing different site
types. The effect of all available meteorological variables on PM10
concentrations was estimated using Generalized Additive Models. Data from
each season were treated separately. The most important variables affecting
PM10 concentrations in winter, autumn and spring were wind gust, the
precipitation rate of the previous day, the precipitation rate of the
current day and the boundary layer depth. In summer, the most important
variables were wind gust, Julian day and afternoon temperature. In addition,
temperature was important in winter. A "weekend effect" was identified due
to the selection of variable "day of the week" for some stations. Thursday
contributes to an increase of 13% whereas Sunday contributes to a
reduction of 12% of PM10 concentrations compared to Monday on average
over 9 stations for the yearly data. The estimated effects of meteorological
variables were removed from the measured PM10 values to obtain the PM10
variability and trends due to other factors and processes, mainly PM10
emissions and formation of secondary PM10 due to trace gas emissions. After
applying this process, the PM10 variability was much lower, especially in
winter where the ratio of adjusted over measured mean squared error was 0.27
on average over all considered sites. Moreover, PM10 trends in winter were
more negative after the adjustment for meteorology and they ranged between
−1.25 μg m−3 yr−1 and 0.07 μg m−3 yr−1. The
adjusted trends for the other seasons ranged between −1.34 μg m−3 yr−1 and −0.26 μg m−3 yr−1 in spring,
−1.40 μg m−3 yr−1 and −0.28 μg m−3 yr−1 in summer and −1.28 μg m−3 yr−1 and
−0.11 μg m−3 yr−1 in autumn.
The estimated trends of meteorologically adjusted PM10 were in general
non-linear. The two urban street sites considered in the study, Bern and
Lausanne, experienced the largest reduction in measured and adjusted PM10
concentrations. This indicates a verifiable effect of traffic emission
reduction strategies implemented during the past two decades. The average
adjusted yearly trends for rural, urban background and urban street stations
were −0.37, −0.53 and −1.2 μg m−3 yr−1 respectively. The
adjusted yearly trends for all stations range from
−0.15 μg m−3 yr−1 to −1.2 μg m−3 yr−1 or −1.2% yr−1 to −3.3% yr−1. |
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