INTERCOMPARISON OF SNOW SAMPLING AND ANALYSIS WITHIN THE ALPINE-WIDE SNOWPACK INVESTIGATION (SNOSP)

In order to investigate the seasonal and geographical distribution of snow concentrations and deposition fluxes of environmentally relevant ionic species in the Alps, the international program SNOSP was initiat ed. In the framework of this program, intercomparisons of snow samplin g techniques and analytical methods to determine the ionic species Cl- , NO3-, SO42-, K+, Na+, NH4+, Mg2+, and Ca2+, as well as the pH and th e specific conductivity were performed. The concentrations of these sp ecies in the snow samples collected in the SNOSP program varied by ord ers of magnitude with, e.g., concentrations of NO3-, SO42-, and NH4+ r anging from 0.2-60, 0.2-90, and 0.1-60 mu eq L(-1), respectively. The intercomparisons revealed a reasonable agreement of the determinations of the species Cl-, NO3-, SO42-, Na+, and NH4+ in snow. Results were less satisfactory for K+, Mg2+, Ca2+, and H+, mainly due to the very l ow concentrations. In conclusion, recommendations are formulated for t he reliable derivation of chemical inventories from snow packs.