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| Titel |
Pure component vapor pressures of organic isomers |
| VerfasserIn |
Caroline Dang, Thomas Bannan, David Topping |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250137725
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| Publikation (Nr.) |
 EGU/EGU2017-530.pdf |
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| Zusammenfassung |
| Atmospheric aerosols affect the Earth’s climate directly through light scattering
and absorption as well as indirectly by affecting cloud formation. There are many
unanswered questions about how material properties of organic aerosols affect
the climate. Predicting the formation of secondary organic aerosol (SOA), arising
from gas to particle partitioning of potentially millions of compounds, remains
one of the most challenging aspects in this regards. Of particular importance on
predicting SOA formation is the saturation vapor pressure of each component. This
property is typically obtained from group contribution methods (GCMs). However, it is
currently unclear as to what level of accuracy is required or attainable from such
techniques. Researchers have recently been able to measure low vapor pressures (lower
limit of 10−8 Pa) experimentally using various techniques, and the University of
Manchester Knudsen Effusion Mass Spectrometer (KEMS) has previously been used to
measure vapor pressure of low volatility organics. Our recent KEMS work shows that
functional group positioning has an effect on vapor pressure that is not accurately
captured with estimation methods, and that experimental vapor pressures are 1-4
orders of magnitudes lower than predictive techniques. This has atmospheric impact
through the variable amount of organic aerosol that is predicted to condense. In
this study we present new measurements from the KEMS that can then be used
to refine different experimental vapor pressure techniques as well as to provide
data sets for building regression models to improve current predictive techniques. |
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