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| Titel |
Simultaneous measurements of peroxyacetyl nitrate and peroxyacetic acid by Chemical Ionization Mass Spectrometry (CIMS): contrasting boreal forest with rural continental Europe |
| VerfasserIn |
G. J. Phillips, N. Pouvesle, J. Thieser, R. Axinte, G. Schuster, H. Fischer, J. Williams, J. N. Crowley |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250066581
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| Zusammenfassung |
| The peroxyacetyl radical (PA) is formed via the photochemical oxidation of a number of
different VOCs. PA radical acts as the source of peroxyacetyl nitrate (PAN), via the reaction
with NO2, and peroxyacetic acid (PAA), via reaction with the HO2 radical. PAN can act
as a temporary reservoir of both PA radical and NO2 transporting NOx far from
source regions, whereas PAA lifetimes, dominated by deposition, are shorter. We
present simultaneous measurements of PAN and PAA in different environments and
study the chemistry of the PA radical in contrasting chemical and meteorological
conditions.
PAN and PAA were measured simultaneously using CIMS during two field intensives
with contrasting meteorological and chemical conditions. The HUMPPA-COPEC 2010
campaign took place during July-August 2010 at the SMEAR II field site, located in boreal
forest near Hyytiälä, Finland [1]. The campaign was characterised by above average
temperatures with large emissions of BVOCs from the boreal forest. The Particles and
Radicals: Diel observations of the impact of urban and biogenic Emissions (PARADE)
campaign took place during August-September 2011 at the mountaintop fieldsite on
the Kleiner Feldberg, Hessen, Germany, approximately 10 km north of Frankfurt.
Temperatures were markedly lower during PARADE compared to HUMPPA and the site
had much lower impact from VOCs and a much larger impact from anthropogenic
emissions.
PAA was found to be a large proportion of ΣPA(PAA+PAN) during the HUMPPA
campaign, approaching 50% on occasion. In addition, PAA was found to make up a
significant fraction of the total organic peroxides. In contrast, ΣPA(PAA+PAN)during
PARADE was dominated by PAN reflecting the lower temperatures and NOx levels.
[1] J. Williams et al, 2011, Atmos. Chem. Phys., 11, 10599-10618 |
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