Relocation and Preferential Elution of Acidic Solute through the Snowpack of a Small, Remote, High-Altitude Scottish Catchment

Abstract

This isolated snowpack shows wide spatial variability in composition, with 15 samples from a 700 m transect giving coefficients of variance of more than 50% for most of the major ions. Cations showed somewhat less variability than anions. Preferential elution, i.e. the more rapid loss of some ions from the pack than others, was more readily observed in the composition of meltwaters because of the high variability in snowpack composition. Preferential elution could be found in the snowpack where it was possible to resample a well-defined surface during a period of ablation. The elution sequence established from these surfaces was although the position of the hydrogen and ammonium ions may be affected by buffering. The sequence compares reasonably well with a generalized one assembled from earlier studies, where is usually eluted quickly and sodium and chloride rather slowly. The evolution of the snowpack composition towards solute depletion, but relative richness in chloride, is clearly represented in triangular diagrams.