1Danish Meterological Institute, Lyngbyvej 100, 2100 Kbh Ø, Denmark
2Technical University Ilmenau (TUI), Institute for Physics, Postfach 100565, 98684 Ilmenau, Germany
3Karlsruhe Institute of Technology (KIT), Institute for Meteorology and Climate Research, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
Received: 01 Oct 2010 – Discussion started: 02 Nov 2010
Abstract. Atmospheric liquid and solid water particles are stabilized if they are coated with either negative or positive electric charge. The surface charge causes an increase of the partial pressure of water vapour close to the surface of each particle, effectively allowing the particles to remain in their condensed phase even if the environmental relative humidity drops below unity. The theory, briefly presented in this paper, predicts a zero parameter relation between surface charge density and water vapour pressure. This relation was tested in a series of Electrodynamic Balance experiments. The measurements were performed by stabilizing charged droplets of pure water near an ice-surface. We observed a divergence in radius as the temperature approached the freezing point from below. We find that the measurements confirm the theory within the experimental uncertainty. In some cases this generally overlooked effect may have impact on cloud processes and on results produced by Electrodynamic Balance experiments.
Revised: 22 Feb 2011 – Accepted: 28 Feb 2011 – Published: 07 Mar 2011
Nielsen, J. K., Maus, C., Rzesanke, D., and Leisner, T.: Charge induced stability of water droplets in subsaturated environment, Atmos. Chem. Phys., 11, 2031-2037, doi:10.5194/acp-11-2031-2011, 2011.