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| Titel |
Ice nucleation activity of polysaccharides |
| VerfasserIn |
Magdalena Bichler, Laura Felgitsch, Thomas Haeusler, Verena Seidl-Seiboth, Hinrich Grothe |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250102481
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| Publikation (Nr.) |
 EGU/EGU2015-1805.pdf |
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| Zusammenfassung |
| Heterogeneous ice nucleation is an important process in the atmosphere. It shows direct
impact on our climate by triggering ice cloud formation and therefore it has much influence
on the radiation balance of our planet (Lohmann et al. 2002; Mishchenko et al. 1996).
The process itself is not completely understood so far and many questions remain
open.
Different substances have been found to exhibit ice nucleation activity (INA). Due to their
vast differences in chemistry and morphology it is difficult to predict what substance will
make good ice nuclei and which will not. Hence simple model substances must be found and
be tested regarding INA.
Our work aims at gaining to a deeper understanding of heterogeneous ice nucleation.
We intend to find some reference standards with defined chemistry, which may
explain the mechanisms of heterogeneous ice nucleation. A particular focus lies on
biological carbohydrates in regards to their INA. Biological carbohydrates are widely
distributed in all kingdoms of life. Mostly they are specific for certain organisms and
have well defined purposes, e.g. structural polysaccharides like chitin (in fungi and
insects) and pectin (in plants), which has also water-binding properties. Since they are
widely distributed throughout our biosphere and mostly safe to use for nutrition
purposes, they are well studied and easily accessible, rendering them ideal candidates as
proxies.
In our experiments we examined various carbohydrates, like the already mentioned chitin
and pectin, as well as their chemical modifications.
Lohmann U.; A Glaciation Indirect Aerosol Effect Caused by Soot Aerosols; J. Geoph.
Res.; Vol. 24 No.4; pp 11-1 - 11-4; 2002
Mishchenko M.I., Rossow W.B., Macke A., Lacis A. A.; Sensitivity of Cirrus Cloud
Albedo, Bidirectional Reflectance and Optical Thickness Retrieval Accuracy to
Ice Particle Shape, J. Geoph. Res.; Vol. 101, No D12; pp. 16,973 - 16,985; 1996 |
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