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| Titel |
Peroxy acetyl nitrate (PAN) at Jungfraujoch from different source regions |
| VerfasserIn |
Shubha Pandey, Johannes Staehelin, Stephan Henne, Uwe Weers, Martin Steinbacher, Christoph Zellweger |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250045614
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| Zusammenfassung |
| PAN (Peroxyacetyl nitrate) is a reactive nitrogen species which is formed from NOx and
volatile organic compounds (VOC) by photochemistry. The life time of PAN is highly
temperature dependent therefore, it acts as reservoir for NOx in cold temperatures and
playing key role in transporting nitrogen species and further, enhancing O3 production during
intercontinental transport [Hudman 2004, Zhang 2008]. In our study we present continuous
PAN measurements from year 2009 to 2010 and campaign measurements of 2008 performed
at high alpine observatory, Jungfraujoch (Switzerland, 3580 m asl). Prior to our
measurements, continuous PAN measurements were performed at Jungfraujoch in 1997
-1998 by Zellweger et al. [2000] . Both these measurements indicate that PAN
concentrations tend to be higher in spring and summer. We compared the PAN
measurements and traced the origin of air masses by trajectory analysis for both these time
periods to evaluate the contribution of different continental sources. Trajectories were
calculated at European and hemispheric scale and attributed to different source
regions.
20 day backward trajectories were calculated using Lagranto (Global model, with
horizontal resolution 10 x10) to evaluate the contribution of long range transport from
different continents. Based on the recent boundary layer contact, PAN measurements were
attributed mainly to three source regions; Europe, Asia and North America. The results
showed that contribution of Europe is dominant in all the season especially in spring and
summer while contribution from North America and Asia become significant in the autumn
and winter months.
Further, European continental sources were evaluated using COSMO (Consortium for
Small-scale Modeling) model trajectories which covers European domain on a horizontal
resolution of 7 km x 7 km. 3 days backward trajectories were calculated and analysis was
extended to clustering of trajectories based on the boundary layer contact. Further, these
trajectories were combined with measurements to attribute possible source regions. The
results showed that the air masses coming from northerly advection including Germany and
Po valley in the south contributes to the higher PAN concentrations which were found in
spring seasons.
References:
Hudman, R. C., et al. (2004), Ozone production in transpacific Asian pollution plumes
and implications for ozone air quality in California, J. Geophys. Res., 109, D23S10, 14
pp
Zellweger, C., et al. (2000), Summertime NOyspeciation at the Jungfraujoch, 3580 m
above sea level, J. Geophys. Res., 105, 6655 - 6667 (2000).
Zhang, L., et al. (2008), Transpacific transport of ozone pollution and the effect of recent
Asian emission increases on air quality in North America: an integrated analysis using
satellite, aircraft, ozonesonde, and surface observations, Atmos. Chem. Phys., 8, 6117–6136 |
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