ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-8-4911-2008 The role of atmospheric ions in aerosol nucleation – a review Enghoff M. B. 1 Svensmark H. 1 National Space Institute, Technical University of Denmark, Copenhagen, Denmark 27 08 2008 8 16 4911 4923 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/8/4911/2008/acp-8-4911-2008.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/4911/2008/acp-8-4911-2008.pdf

Atmospheric aerosols affect climate and yet the reason for many observed events of new aerosol formation is not understood. One of the theories put forward to explain these events is that the presence of ions can enhance the formation of aerosols. The theory is called Ion Induced Nucleation and in this paper the state of observations, theory and experiments within the field will be reviewed. While evidence for Ion Induced Nucleation is accumulating the exact mechanism is still not known and more research is required to understand and quantify the effect.

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