Aerosols, Clouds, and Atmospheric Chemistry

Organic aerosols are ubiquitous in the atmos-phere. At low temperatures they are known to become glassy, that is, amorphous, non-crystalline solids. AIDA cloud chamber experiments demonstrate heterogeneous nucleation of ice on glassy citric acid particles (Murray et al., Nature Geoscience 2010).The AIDA campaign ICE-02 in July 2010 will address other organics as well as mixtures of organic and inorganic substances.

In the first global modelling study of heterogeneous ice nucleation by biological particles, Hoose et al. (http://iopscience.iop.org/1748-9326/5/2/024009/fulltext) show that typical atmospheric bacteria, fungal spores and pollen concentrations are too low to make a significant impact for cloud ice and precipitation formation. The research is featured in a news article on environmentalresearchweb. org.

IMK-AAF participates in the new Marsilius Project “The Global Governance of Climate Engineering” which focuses on options and risks in dealing with climate change by technological means. The Marsilius Kolleg was recently established at the University of Heidelberg as a Centre for Advanced Study to promote interdisciplinary dialogue and research.
More about the Climate Engineering Project

The IMK-AAF Atmospheric Nanoscience Group joins a three week measurement campaign at the synchrotron source BESSY II in Berlin. Research objective is the identification of polymorphs of nanometric ironoxide cloud nucleation seeds. Nanoaerosols ablated from meteorites are expected to play a crucial role in the formation of mesospheric noctilucent clouds.

In February, IMK-AAF conducted a feasibility study at the environmental research station Schneefernerhaus (UFS). The aim of the study was to show that the UFS is well suited to measure aerosol - cloud interactions in natural clouds.