 |
| Titel |
Airborne observations of IEPOX-derived isoprene SOA in the Amazon during SAMBBA |
| VerfasserIn |
J. D. Allan, W. T. Morgan, E. Darbyshire, M. J. Flynn, P. I. Williams, D. E. Oram, P. Artaxo, J. Brito, J. D. Lee, H. Coe |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 20 ; Nr. 14, no. 20 (2014-10-29), S.11393-11407 |
| Datensatznummer |
250119127
|
| Publikation (Nr.) |
 copernicus.org/acp-14-11393-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Isoprene is a potentially highly significant but currently poorly quantified
source of secondary organic aerosols (SOA). This is especially important in
the tropics, where large rainforests act as significant sources of isoprene.
Methylfuran, produced through thermal decomposition during analysis, has
recently been suggested as a marker for isoprene SOA formation through the
isoprene epoxydiol (IEPOX) route, which mostly occurs under low NOx
conditions. This is manifested as a peak at m/z=82 in Aerodyne Aerosol Mass
Spectrometer (AMS) data. Here we present a study of this marker measured
during five flights over the Amazon rainforest on board the UK Facility for
Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft during the
South American Biomass Burning Analysis (SAMBBA) campaign. Cases where this
marker is and is not present are contrasted and linked to the presence of
acidic seed particles, lower NOx concentrations and higher humidities.
There are also data to suggest a role of organic nitrogen in the particulate
composition. Furthermore, an inspection of the vertical trends of the marker
indicates that concentrations are highest at the top of the boundary layer
(possibly due to semivolatile repartitioning) and that upwards through the free
troposphere, the mass spectral profile evolves towards that of low
volatility oxygenated aerosol. These observations offer insights into the
behaviour of IEPOX-derived SOA formation above the Amazon rainforest and the
suitability of methylfuran as a marker for this process. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|