 |
| Titel |
In-situ ambient quantification of monoterpenes, sesquiterpenes, and related oxygenated compounds during BEARPEX 2007: implications for gas- and particle-phase chemistry |
| VerfasserIn |
N. C. Bouvier-Brown, A. H. Goldstein, J. B. Gilman, W. C. Kuster, J. A. Gouw |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 15 ; Nr. 9, no. 15 (2009-08-05), S.5505-5518 |
| Datensatznummer |
250007556
|
| Publikation (Nr.) |
 copernicus.org/acp-9-5505-2009.pdf |
|
|
|
|
|
| Zusammenfassung |
| We quantified ambient mixing ratios of 9 monoterpenes, 6 sesquiterpenes,
methyl chavicol, the oxygenated terpene linalool, and nopinone using an
in-situ gas chromatograph with a quadrupole mass spectrometer (GC-MS). These
measurements were a part of the 2007 Biosphere Effects on AeRosols and
Photochemistry EXperiment (BEARPEX) at Blodgett Forest, a ponderosa pine
forest in the Sierra Nevada Mountains of California. To our knowledge, these
observations represent the first direct in-situ ambient quantification of
the sesquiterpenes α-bergamotene, longifolene, α-farnesene,
and β-farnesene. From average diurnal mixing ratio profiles, we show
that α-farnesene emissions are dependent mainly on temperature
whereas α-bergamotene and β-farnesene emissions are
temperature- and light-dependent. The amount of sesquiterpene mass
quantified above the canopy was small (averaging a total of 3.3 ppt during
the day), but nevertheless these compounds contributed 7.6% to the
overall ozone-olefin loss rate above the canopy. Assuming that the
monoterpene-to-sesquiterpene emission rate in the canopy is similar to that
observed in branch enclosure studies at the site during comparable weather
conditions, and the average yield of aerosol mass from these sesquiterpenes
is 10–50%, the amount of sesquiterpene mass reacted within the Blodgett
Forest canopy alone accounts for 6–32% of the total organic aerosol mass
measured during BEARPEX. The oxygenated monoterpene linalool was also
quantified for the first time at Blodgett Forest. The linalool mass
contribution was small (9.9 ppt and 0.74 ppt within and above the canopy,
respectively), but it contributed 1.1% to the total ozone-olefin loss
rate above the canopy. Reactive and semi-volatile compounds, especially
sesquiterpenes, significantly impact the gas- and particle-phase chemistry
of the atmosphere at Blodgett Forest and should be included in both biogenic
volatile organic carbon emission and atmospheric chemistry models. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|