Atmos. Chem. Phys. Discuss., 11, 21171-21200, 2011
www.atmos-chem-phys-discuss.net/11/21171/2011/
doi:10.5194/acpd-11-21171-2011
© Author(s) 2011. This work is distributed
under the Creative Commons Attribution 3.0 License.
Review Status
This discussion paper has been under review for the journal Atmospheric Chemistry and Physics (ACP). Please refer to the corresponding final paper in ACP.
Deposition freezing on mineral dust particles: a case against classical nucleation theory with the assumption of a single contact angle
M. J. Wheeler and A. K. Bertram
Department of Chemistry, University of British Columbia, Vancouver, BC CAN V6T 1Z1, Canada

Abstract. Deposition freezing on two mineral species, kaolinite and illite, was studied using a flow cell coupled to an optical microscope at ∼240 K. The results show that the onset Sice (defined as the Sice conditions when ice first nucleated) is a strong function of the surface area available for nucleation, varying from 100 % to 125 %. The surface area dependent data could not be described accurately using classical nucleation theory and the assumption of a single contact angle (defined here as the single-α model). These results suggest that caution should be applied when using contact angles determined from onset Sice data and the single-α model. In contrast to the single-α model, the active site model, the deterministic model, and a model with a normal distribution of contact angles fit the data within experimental uncertainties. Parameters from the fits to the data are presented.

Citation: Wheeler, M. J. and Bertram, A. K.: Deposition freezing on mineral dust particles: a case against classical nucleation theory with the assumption of a single contact angle, Atmos. Chem. Phys. Discuss., 11, 21171-21200, doi:10.5194/acpd-11-21171-2011, 2011.
 
Search ACPD
Discussion Paper
    XML
    Citation
    Final Revised Paper
    Share