Snow accumulation, firn temperature and solar radiation in the area of the Colle Gnifetti core drilling site (Monte Rosa, Swiss Alps): Distribution patterns and interrelationships

Abstract

Distributional patterns of glaciological parameters at the Colle Gnifetti core drilling site are described and their interrelationships are briefly discussed. Observations within a stake network established in 1980 furnish information about snow accumulation (short term balance), submergence velocity of ice flow (long term balance), ram hardness (melt layer stratigraphy), and firn temperature. In addition, a numerical model was used to estimate local variations of available radiant energy. Melt layer formation is considerably more intensive on the south facing parts of the firn saddle where incoming radiation is high. These melt layers seem to effectively protect some of the fallen snow from wind erosion. As a result, balance is up to one order of magnitude larger on south facing slopes. Heat applied to the surface is therefore positively correlated with balance, whereas the relation between solar radiation and firn temperature is less clear. Distributional patterns of submergence velocity confirm that the observed spatial variability of surface balance is representative for longer time periods and greatly influences the time scale and the stratigraphy of firn and ice cores from Colle Gnifetti.