The composition of acidic meltwaters during snowmelt in the Scottish Highlands

The chemical composition of meltwaters collected within a remote snowpack in the Scottish Highlands was modeled by the mixing of two components. The first component is concentrated and may originate from the solute-rich waters held at the crystal surfaces, whereas the second is dilute and possibly originates from the melting of the solute-poor interiors of snow and ice crystals. The proportional ionic composition of the components differ. In general, meltwaters become more dilute as ablation proceeds, and solute near to the surface of the snowpack is rapidly leached. Meltwaters do not necessarily become more concentrated as they percolate through the snowpack. Snowpack hydrology is likely to be a major control on the depth-concentration relationship. The composition of meltwaters from deeper within the snowpack provides some evidence for the preferential elution of acidic solute (H+, S0₄ ^2- and N0₃ ^-) with respect to sea salt (Na⁺ and Cl^-). However, changes in the ionic concentration of these meltwaters, which are already proportionally enriched in sea salt, brought about by preferential elution are small in comparison to changes in concentration as a result of two component mixing or dilution © 1987 D. Reidel Publishing Company.