SCAVENGING OF SO2 AND HCL DURING GROWTH OF ICE CRYSTALS BY VAPOR DIFFUSION

Scavenging of HCl and SO2 during snow-crystal growth by sublimation of water vapour from liquid droplets was studied in a cylindrical chambe r housed in a cold room. The SO2 sorption in crystals appears to be in dependent of the gaseous-phase concentration in the tested 1.2-7.4 ppm v range. The mean sulphur (as sulphate) concentration in crystals was S(VI) = (9.3 +/- 5.5) ppm. A second set of experiments was performed i n the same conditions using HCl. The resulting data indicate that for Cl-liq(-) < 20 ppm all the HCl goes from the droplets into the ice, wh ereas for higher liquid phase Cl- concentrations, the solid phase Cl- decreases to about 0.35 times the value in the initial liquid phase.