Influence of the ice growth rate on the incorporation of gaseous HCl F. Domine1 and C. Rauzy1,2 1CNRS, Laboratoire de Glaciologie et Geophysique de l’Environnement, BP 96, 38402 Saint Martin d’Hères cedex, France 2now at: Department of Chemistry, University of Fribourg, CH-1700 Fribourg, Switzerland
Abstract. Ice crystals were grown in the laboratory at −15°C, at different growth
rates and in the presence of a partial pressure of HCl of 1.63×10-3 Pa, to test whether the ice growth rate influences the amount of HCl taken
up, XHCl, as predicted by the ice growth mechanism of Domine and Thibert
(1996). The plot of HCl concentration in
ice as a function of growth rate has the aspect predicted by that mechanism:
XHCl decreases with increasing growth rate, from a value that depends
on thermodynamic equilibrium to a value that depends only on kinetic
factors. The height of the growth steps of the ice crystals is determined to
be about 150 nm from these experiments. We discuss that the application of
these laboratory experiments to cloud ice crystals and to snow metamorphism
is not quantitatively possible at this stage, because the physical variables
that determine crystal growth in nature, and in particular the step height,
are not known. Qualitative applications are attempted for HCl and HNO3
incorporation in cloud ice and snowpack crystals.
Citation: Domine, F. and Rauzy, C.: Influence of the ice growth rate on the incorporation of gaseous HCl, Atmos. Chem. Phys., 4, 2513-2519, doi:10.5194/acp-4-2513-2004, 2004.