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| Titel |
The impact of bark beetle infestations on monoterpene emissions and secondary organic aerosol formation in western North America |
| VerfasserIn |
A. R. Berg, C. L. Heald, K. E. Huff Hartz, A. G. Hallar, A. J. H. Meddens, J. A. Hicke, J.-F. Lamarque, S. Tilmes |
| 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 ; 13, no. 6 ; Nr. 13, no. 6 (2013-03-15), S.3149-3161 |
| Datensatznummer |
250018524
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| Publikation (Nr.) |
 copernicus.org/acp-13-3149-2013.pdf |
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| Zusammenfassung |
Over the last decade, extensive beetle outbreaks in western North America
have destroyed over 100 000 km2 of forest throughout British Columbia
and the western United States. Beetle infestations impact monoterpene
emissions through both decreased emissions as trees are killed (mortality
effect) and increased emissions in trees under attack (attack effect). We
use 14 yr of beetle-induced tree mortality data together with beetle-induced
monoterpene emission data in the National Center for Atmospheric Research
(NCAR) Community Earth System Model (CESM) to investigate the impact of
beetle-induced tree mortality and attack on monoterpene emissions and
secondary organic aerosol (SOA) formation in western North America.
Regionally, beetle infestations may have a significant impact on monoterpene
emissions and SOA concentrations, with up to a 4-fold increase in
monoterpene emissions and up to a 40% increase in SOA concentrations in
some years (in a scenario where the attack effect is based on observed
lodgepole pine response). Responses to beetle attack depend on the extent of
previous mortality and the number of trees under attack in a given year,
which can vary greatly over space and time. Simulated enhancements peak in
2004 (British Columbia) and 2008 (US). Responses to beetle attack are shown
to be substantially larger (up to a 3-fold localized increase in summertime
SOA concentrations) in a scenario based on bark-beetle attack in spruce
trees. Placed in the context of observations from the IMPROVE network, the
changes in SOA concentrations due to beetle attack are in most cases small
compared to the large annual and interannual variability in total organic
aerosol which is driven by wildfire activity in western North America. This
indicates that most beetle-induced SOA changes are not likely detectable in
current observation networks; however, these changes may impede efforts to
achieve natural visibility conditions in the national parks and wilderness
areas of the western United States. |
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