Title Freezing of water droplets colliding with kaolinite particles
Author Svensson, E.A.; Delval, C.; von Hessberg, P.; Johnson, M.S.; Pettersson, J.B.C.
Author Affil Svensson, E.A., University of Goteborg, Department of Chemistry, Atmospheric Science, Goteborg, Sweden. Other: University of Copenhagen, Denmark; Ecole Polytechnique Fédérale de Lausanne, Switzerland
Source Atmospheric Chemistry and Physics, 9(13), p.4295-4300, . Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1680- 7316
Publication Date 2009
Notes In English. Published in Atmospheric Chemistry and Physics Discussions: 27 January 2009, http://www.atmos-chem-phys- discuss.net/9/2417/2009/acpd-9-2417-2009.html ; accessed in Apr. 2011. 36 refs. GeoRef Acc. No: 310521
Index Terms aerosols; clay minerals; clouds (meteorology); condensation; cooling; crystals; dust; experimentation; freezing; humidity; ice; ice crystals; particles; sediments; temperature; water; water temperature; clastic sediments; clouds; experimental studies; heterogeneous materials; kaolinite; laboratory studies; sheet silicates; silicates
Abstract Contact freezing of single supercooled water droplets colliding with kaolinite dust particles has been investigated. The experiments were performed with droplets levitated in an electrodynamic balance at temperatures from 240 to 268 K. Under relatively dry conditions (when no water vapor was added) freezing was observed to occur below 249 K, while a freezing threshold of 267 K was observed when water vapor was added to the air in the chamber. The effect of relative humidity is attributed to an influence on the contact freezing process for the kaolinite-water droplet system, and it is not related to the lifetime of the droplets in the electrodynamic balance. Freezing probabilities per collision were derived assuming that collisions at the lowest temperature employed had a probability of unity. Mechanisms for contact freezing are briefly discussed.
URL http://www.atmos-chem-phys.net/9/4295/2009/acp-9-4295-2009.pdf
Publication Type journal article
Record ID 65007080