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| Titel |
Contributions of individual reactive biogenic volatile organic compounds to organic nitrates above a mixed forest |
| VerfasserIn |
K. A. Pratt, L. H. Mielke, P. B. Shepson, A. M. Bryan, A. L. Steiner, J. Ortega, R. Daly, D. Helmig, C. S. Vogel, S. Griffith, S. Dusanter, P. S. Stevens, M. Alaghmand |
| 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 ; 12, no. 21 ; Nr. 12, no. 21 (2012-11-05), S.10125-10143 |
| Datensatznummer |
250011557
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| Publikation (Nr.) |
 copernicus.org/acp-12-10125-2012.pdf |
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| Zusammenfassung |
| Biogenic volatile organic compounds (BVOCs) can react in the atmosphere to
form organic nitrates, which serve as NOx (NO + NO2) reservoirs,
impacting ozone and secondary organic aerosol production, the oxidative
capacity of the atmosphere, and nitrogen availability to ecosystems. To
examine the contributions of biogenic emissions and the formation and fate
of organic nitrates in a forest environment, we simulated the oxidation of
57 individual BVOCs emitted from a rural mixed forest in northern Michigan.
Key BVOC-oxidant reactions were identified for future laboratory and field
investigations into reaction rate constants, yields, and speciation of
oxidation products. Of the total simulated organic nitrates, monoterpenes
contributed ~70% in the early morning at ~12 m above the
forest canopy when isoprene emissions were low. In the afternoon, when
vertical mixing and isoprene nitrate production were highest, the simulated
contribution of isoprene-derived organic nitrates was greater than 90% at
all altitudes, with the concentration of secondary isoprene nitrates
increasing with altitude. Notably, reaction of isoprene with NO3
leading to isoprene nitrate formation was found to be significant (~8%
of primary organic nitrate production) during the daytime, and
monoterpene reactions with NO3 were simulated to comprise up
to ~83% of primary organic nitrate production at night. Lastly, forest
succession, wherein aspen trees are being replaced by pine and maple trees,
was predicted to lead to increased afternoon concentrations of
monoterpene-derived organic nitrates. This further underscores the need to
understand the formation and fate of these species, which have different
chemical pathways and oxidation products compared to isoprene-derived
organic nitrates and can lead to secondary organic aerosol formation. |
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