The anthropogenic impact on snow chemistry at Colle Gnifetti, Swiss Alps ...

• Main Authors: Wagenbach, D., Münnich, K.O., Schotterer, U., Oeschger, H.
• Format: Text
• Language: unknown
• Published: International Glaciological Society 1988
• Subjects: 530 Physics; ice core
• Online Access: https://dx.doi.org/10.48350/158758; https://boris.unibe.ch/158758/

By chemical analysis of the upper 40 m of a 124 m ice core from a high-altitude Alpine glacier (Colle Gnifetti, Swiss Alps; 4450 m a.s.l.), records of mineral dust, pH, melt-water conductivity, nitrate and sulfate are obtained. The characteristics of the drilling site are discussed, as derived from glacio-meteorological and chemical analysis. As a consequence of high snow-erosion rates (usually during the winter months), annual snow accumulation is dominated by summer precipitation. Clean-air conditions prevail even during summer; however, they are frequently interrupted by polluted air masses or by air masses which are heavily loaded with desert dust. Absolutely dated reference horizons for Saharan dust, together with the position of the broad nuclear-weapon tritium peak, provide the time-scale for the following statements: (1) Since at least the turn of the century the background melt-water conductivity has been rising steadily, as has the mean snow acidity. The trend of increasing background conductivity ...