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| Titel |
Laboratory experiments on pine pollen and their abilities to nucleate ice |
| VerfasserIn |
Fabian Weiss, Philipp Baloh, Karin Whitmore, Hinrich Grothe |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250033112
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| Zusammenfassung |
| Only recently Pratt et al. (2009) have revealed by field measurements with an aerosol mass
spectrometer that an amount of 33% of the matter in upper tropospheric aerosols consists of
biological materials. In contrast to inorganic compounds the properties of the biological
materials have not yet been investigated to the same extent.
As commonly known, aerosols act as cloud nuclei and so affect the climate indirectly.
The IPCC report 2007 presented the impact of the aerosol and cloud interaction
as the largest uncertainty in Earth’s radiation balance. Therefore, the necessity to
investigate biologic material comes into play to improve the knowledge of all influencing
factors.
Pine pollen has been used in this investigation because of various advantages: On one
hand, the pine tree is one of the most common species in northern hemisphere and
therefore its pollen should be available in a sufficient amount in the troposphere. On
the other hand, pollen has a diverse surface structure that might act as good ice
nuclei.
The interaction with oxidizing trace gases in the troposphere might lead to a different surface
chemistry and thus to better nucleation properties. Nitric oxides are among the most reactive
species in the atmosphere. Hence, in our laboratory experiments some pollen samples
were treated with NO2. Finally, those two kinds of pine pollen were investigated by
spectroscopic methods and changes in morphology were observed by SEM. The used
spectroscopic methods were FTIR (ATR and DRIFTS mode) and Raman Spectroscopy. |
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