Changes of major ion concentrations in melting snow and terrestrial waters from northern Victoria Land, Antarctica.

Concentrations of major ions (Cl-, NO3-, SO42-, Na+, K+,Mg2+, Ca2+) where
measure in melting snow and water samples from stream and lakes in ice-free
areas throughout northern Victoria Land. Most ions in snow and terrestrial
water are derived from the marine environment and their concentrations are
extremely variable in species and time, especially in water systems without
melting snow and ice. The distance from the sea, snow sublimation, changes in
water inflow, evaporative concentrations, weathering and drainage processes in
catchment, nesting seabirds and aquatic microbiota are among factors which most
influence ion composition variability. Comparison with data from twelve years
ago in the same lakes indicates that the warming trend detected in Terra Nova
Bay station during this period did not affect the biogeochemistry of water
systems. Water from a lake which recently experienced a lowering of the water
level showed a remarkable increase in SO42- concentrations. We hypothesized
that the differential mobility of sulphate salts in the Antarctic soils, the
biosynthesis of sulphur compounds in the lake, and the progressive decrease of
the water volume are factors involved in the increase of SO42- concentrations.