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| Titel |
Long-term trends in aerosol optical characteristics in the Po Valley, Italy |
| VerfasserIn |
J. P. Putaud, F. Cavalli, S. Martins dos Santos, A. Dell'Acqua |
| 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 ; 14, no. 17 ; Nr. 14, no. 17 (2014-09-05), S.9129-9136 |
| Datensatznummer |
250119005
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| Publikation (Nr.) |
 copernicus.org/acp-14-9129-2014.pdf |
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| Zusammenfassung |
| Aerosol properties have been monitored by ground-based in situ and remote sensing
measurements at the station for atmospheric research located in Ispra, on the
edge of the Po Valley, for almost one decade. In situ measurements are performed
according to Global Atmosphere Watch recommendations, and quality is assured
through the participation in regular inter-laboratory comparisons. Sun-photometer data are produced by the Aerosol Robotic Network (AERONET). Data show significant decreasing
trends over the 2004–2010 period for a number of variables, including particulate
matter (PM) mass concentration, aerosol scattering, backscattering and
absorption coefficients, and aerosol optical thickness (AOT). In situ measurement
data show no significant trends in the aerosol backscatter ratio, but they do show a
significant decreasing trend of about −0.7 ± 0.3% yr−1 in the
aerosol single scattering albedo (SSA) in the visible light range. Similar
trends are observed in the SSA retrieved from sun-photometer measurements.
Correlations appear between in situ PM mass concentration
and aerosol scattering coefficient, on the one hand, and elemental
carbon (EC) concentration and aerosol absorption coefficient, on the other hand. However, no increase in the EC / PM
ratio was observed, which could have explained the decrease in SSA. The
application of a simple approximation to calculate the direct radiative
forcing by aerosols suggests a significant diminution in their cooling
effect, mainly due to the decrease in AOT. Applying the methodology we
present to those sites, where the necessary suite of measurements is
available, would provide important information to inform future policies for
air-quality enhancement and fast climate change mitigation. |
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