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Titel |
Atmospheric peroxyacetyl nitrate (PAN): a global budget and source attribution |
VerfasserIn |
E. V. Fischer, D. J. Jacob, R. M. Yantosca, M. P. Sulprizio, D. B. Millet, J. Mao, F. Paulot, H. B. Singh, A. Roiger, L. Ries, R. W. Talbot, K. Dzepina, S. Pandey Deolal |
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. 5 ; Nr. 14, no. 5 (2014-03-14), S.2679-2698 |
Datensatznummer |
250118485
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Publikation (Nr.) |
copernicus.org/acp-14-2679-2014.pdf |
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Zusammenfassung |
Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane
volatile organic compounds (NMVOCs) is the principal tropospheric reservoir
for nitrogen oxide radicals (NOx = NO + NO2). PAN enables
the transport and release of NOx to the remote troposphere with
major implications for the global distributions of ozone and OH, the main
tropospheric oxidants. Simulation of PAN is a challenge for global models
because of the dependence of PAN on vertical transport as well as complex and
uncertain NMVOC sources and chemistry. Here we use an improved representation
of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that
it can simulate PAN observations from aircraft campaigns worldwide. The
immediate carbonyl precursors for PAN formation include acetaldehyde (44%
of the global source), methylglyoxal (30%), acetone (7%), and a suite
of other isoprene and terpene oxidation products (19%). A diversity of
NMVOC emissions is responsible for PAN formation globally including isoprene
(37%) and alkanes (14%). Anthropogenic sources are dominant in the
extratropical Northern Hemisphere outside the growing season. Open fires
appear to play little role except at high northern latitudes in spring,
although results are very sensitive to plume chemistry and plume rise.
Lightning NOx is the dominant contributor to the observed PAN
maximum in the free troposphere over the South Atlantic. |
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