 |
| Titel |
Atmospheric oxidation of isoprene and 1,3-butadiene: influence of aerosol acidity and relative humidity on secondary organic aerosol |
| VerfasserIn |
M. Lewandowski, M. Jaoui, J. H. Offenberg, J. D. Krug, T. E. Kleindienst |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 7 ; Nr. 15, no. 7 (2015-04-08), S.3773-3783 |
| Datensatznummer |
250119618
|
| Publikation (Nr.) |
 copernicus.org/acp-15-3773-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| The effects of acidic seed aerosols on the formation of secondary organic
aerosol (SOA) have been examined in a number of previous studies, several of
which have observed strong linear correlations between the aerosol acidity
(measured as nmol H+ m−3 air sample volume) and the percent change
in secondary organic carbon (SOC). The measurements have used several
precursor compounds representative of different classes of biogenic
hydrocarbons including isoprene, monoterpenes, and sesquiterpenes. To date,
isoprene has displayed the most pronounced increase in SOC, although few
measurements have been conducted with anthropogenic hydrocarbons. In the
present study, we examine several aspects of the effect of aerosol acidity on
the secondary organic carbon formation from the photooxidation of
1,3-butadiene, and extend the previous analysis of isoprene.
The photooxidation products measured in the absence and presence of acidic
sulfate aerosols were generated either through photochemical oxidation of
SO2 or by nebulizing mixtures of ammonium sulfate and sulfuric acid into
a 14.5 m3 smog chamber system. The results showed that, like isoprene
and β-caryophyllene, 1,3-butadiene SOC yields linearly correlate with
increasing acidic sulfate aerosol. The observed acid sensitivity of
0.11% SOC increase per nmol m−3 increase in H+ was
approximately a factor of 3 less than that measured for isoprene. The results
also showed that the aerosol yield decreased with increasing humidity for
both isoprene and 1,3-butadiene, although to different degrees. Increasing
the absolute humidity from 2 to 12 g m−3 reduced the 1,3-butadiene
yield by 45% and the isoprene yield by 85%. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|