Transfer of atmospheric constituents into an alpine snow field

Abstract

Simultaneous aerosol and snow sampling was performed during a field campaign at the Alpine site Weissfluhjoch Davos, Switzerland (2540 m a.s.1.) from 1 January through 30 March 1988. In addition, a snow pit was sampled on 30 March 1988. Very good agreement between the new snow and pit snow samples was found for the measured major ions as well as for the stable isotopes δ 18O and δD. Thus, snow pit samples obtained at this site during the winter months yield representative deposition patterns with a conserved stratigraphy. Generally, concentrations in snow were very low, with 3.5, 8.5, 5.2 and 2.4 μeq ℓ −1 for Cl −, NO 3 −, SO 4 2−, respectively. The 36Cl and 10Be concentrations as well as the 10Be/ 36Cl ratios were comparable to the ones measured at Arctic sites. With the exception of NO 3 −, no linear relation was obtained between atmospheric and snow concentrations, showing that the concept of scavenging ratios must be used with caution when looking at single snowfall events. The following precipitation-weighted mean scavenging ratios were found: 300 for NH 4 +, 350 for SO 4 2−, 940 for total NO 3 −(NO 3 −+HNO 3), 175 for 210Pb, and 750 for 10Be.