Atmospheric peroxyacetyl nitrate (PAN)H. B. Singh
, A. Roiger
, Katja Džepina
, D. B. Millet
, Jiandong Mao
, F. Paulot
, R. M. Yantosca
, M. P. Sulprizio
, E. V. Fischer
, D. J. Jacob
, 2014, original scientific article
Abstract: 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.
Found in: ključnih besedah
Summary of found: ...remote troposphere with major implications for the global distributions of ozone and OH, the main... ...representation of NMVOCs in a global 3-D chemical
transport model (GEOS-Chem) and show that it can... ...of PAN is a challenge for global models because of the dependence
of PAN on vertical...
Keywords: peroxyacetyl nitrate, non-methane volatile organic compounds, global 3-D chemical transport model, GEOS-chem
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