BIRCH TREES - SOURCES OF ICE-NUCLEATING MACROMOLECULES

9 Jan 2018, 15:05
20m
NO Building, Room C 60 (ETH Zürich, centre)

NO Building, Room C 60

ETH Zürich, centre

Sonneggstrasse 5 8092 Zürich
Talk Ice Binding Proteins

Speaker

Prof. Hinrich Grothe (TU Wien)

Description

Aerosol-cloud interaction is an important part in understanding the Earth radiation balance and thus global climate. The IPCC indicates the level of understanding of this issue as rather low. This is particularly true for mixed phase clouds and ice clouds. In the recent past a broad variety of aerosols has been test for ice nucleation ability. However, there is still little knowledge about the impact of biological ice nuclei. In particular, biological macromolecules have for a long time been neglected by atmospheric scientists. However, plants are known by biologists to produce macromolecular ice nuclei as a part of their low-temperature survival strategy. In the past, it has been shown by us that birch pollen exhibit ice nucleation active macromolecules at their surface. These molecules can be washed off from the pollen grains and nucleate ice independently. Only recently, we found the same ice nuclei also on secondary and primary wood and on leafs of birch trees. The question remains if these biological ice nuclei can be dispersed through the atmosphere and can impact cloud glaciation processes. Here we apply different spectroscopic and microscopic techniques to gain insights into the nucleation mechanisms and into the chemical signatures of the molecular ice nuclei.

Significance statement

We are searching for the perfect heterogeneous ice nucleus

Primary author

Prof. Hinrich Grothe (TU Wien)

Co-authors

Mrs Laura Felgitsch (TU Wien) Mrs Teresa Seifried (TU Wien)

Presentation materials

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