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| Titel |
Long-term in situ measurements of NOx and NOy at Jungfraujoch 1998-2009: time series analysis and evaluation |
| VerfasserIn |
S. Pandey Deolal, D. Brunner, M. Steinbacher, U. Weers, J. Staehelin |
| 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. 5 ; Nr. 12, no. 5 (2012-03-07), S.2551-2566 |
| Datensatznummer |
250010862
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| Publikation (Nr.) |
 copernicus.org/acp-12-2551-2012.pdf |
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| Zusammenfassung |
| We present an analysis of the NOy (NOx + other oxidized species)
measurements at the high alpine site Jungfraujoch (JFJ, 3580 m a.s.l.) for the
period 1998–2009, which is the longest continous NOy data set reported
from the lower free troposphere worldwide. Due to stringent emission control
regulations, nitrogen oxides (NOx) emissions have been reduced
significantly in Europe since the late 1980s as well as during the
investigation period. However, the time series of NOy at JFJ does not
show a consistent trend but a maximum during 2002 to 2004 and a decreasing
tendency thereafter. The seasonal cycle of NOy exhibits a maximum in
the warm season and a minimum in the cold months, opposite to measurements
in the PBL, reflecting the seasonal changes in vertical transport and
mixing. Except for summer, the seasonal mean NOx concentrations at JFJ
show a high year-to-year variability which is strongly controlled by short
episodic pollution events obscuring any long-term trends. The low
variability in mean and median NOx values in summer is quite remarkable
indicating rapid photochemical conversion of NOx to higher oxidized
species (NOz) of the NOy family on a timescale shorter than the
time required to transport polluted air from the boundary layer to JFJ. In
order to evaluate the quality of the NOy data series, an in-situ
intercomparison with a second collocated NOy analyzer with a separate
inlet was performed in 2009–2010 which showed an overall agreement within
10% including all uncertainties and errors. |
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