Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 12, 8645-8661, 2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
25 Sep 2012
Bacteria in the ECHAM5-HAM global climate model
A. Sesartic1, U. Lohmann1, and T. Storelvmo2 1ETH Zurich, Institute for Atmospheric and Climate Science, 8092 Zurich, Switzerland
2Department of Geology and Geophysics, Yale University, New Haven (CT), USA
Abstract. Some bacteria are among the most active ice nuclei found in nature due to the ice nucleation active proteins on their surface, which serve as active sites for ice nucleation. Their potential impact on clouds and precipitation is not well known and needs to be investigated. Bacteria as a new aerosol species were introduced into the global climate model (GCM) ECHAM5-HAM. The inclusion of bacteria acting as ice nuclei in a GCM leads to only minor changes in cloud formation and precipitation on a global level, however, changes in the liquid water path and ice water path are simulated, specifically in the boreal regions where tundra and forests act as sources of bacteria. Although bacteria contribute to heterogeneous freezing, their impact is reduced by their low numbers compared to other heterogeneous IN. This result confirms the outcome of several previous studies.

Citation: Sesartic, A., Lohmann, U., and Storelvmo, T.: Bacteria in the ECHAM5-HAM global climate model, Atmos. Chem. Phys., 12, 8645-8661,, 2012.
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