|
Titel |
North American acetone sources determined from tall tower measurements and inverse modeling |
VerfasserIn |
L. Hu, D. B. Millet, S. Y. Kim, K. C. Wells, T. J. Griffis, E. V. Fischer, D. Helmig, J. Hueber, A. J. Curtis |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1680-7316
|
Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 13, no. 6 ; Nr. 13, no. 6 (2013-03-25), S.3379-3392 |
Datensatznummer |
250018538
|
Publikation (Nr.) |
copernicus.org/acp-13-3379-2013.pdf |
|
|
|
Zusammenfassung |
We apply a full year of continuous atmospheric acetone measurements from the
University of Minnesota tall tower Trace Gas Observatory (KCMP tall tower;
244 m a.g.l.), with a 0.5° × 0.667° GEOS-Chem
nested grid simulation to develop quantitative new constraints on seasonal
acetone sources over North America. Biogenic acetone emissions in the model
are computed based on the MEGANv2.1 inventory. An inverse analysis of the
tall tower observations implies a 37% underestimate of emissions from
broadleaf trees, shrubs, and herbaceous plants, and an offsetting 40%
overestimate of emissions from needleleaf trees plus secondary production
from biogenic precursors. The overall result is a small (16%) model
underestimate of the total primary + secondary biogenic acetone source in
North America. Our analysis shows that North American primary + secondary
anthropogenic acetone sources in the model (based on the EPA NEI 2005
inventory) are accurate to within approximately 20%. An optimized
GEOS-Chem simulation incorporating the above findings captures 70% of the
variance (R = 0.83) in the hourly measurements at the KCMP tall tower, with
minimal bias. The resulting North American acetone source is 11 Tg a−1,
including both primary emissions (5.5 Tg a−1) and secondary
production (5.5 Tg a−1), and with roughly equal contributions from
anthropogenic and biogenic sources. The North American acetone source alone
is nearly as large as the total continental volatile organic compound (VOC)
source from fossil fuel combustion. Using our optimized source estimates as
a baseline, we evaluate the sensitivity of atmospheric acetone and
peroxyacetyl nitrate (PAN) to shifts in natural and anthropogenic acetone
sources over North America. Increased biogenic acetone emissions due to
surface warming are likely to provide a significant offset to any future
decrease in anthropogenic acetone emissions, particularly during summer. |
|
|
Teil von |
|
|
|
|
|
|