Environmental radionuclides as tracers for transport processes in snow.

Radionuclides are useful tracers for the determination of transport processes from the atmosphere to the hydrosphere by snowfall. Particularly in high altitudinal regions radionuclides released to the environment are efficiently removed from the atmosphere by snow. Once deposited, they will be concentrated in the snow cover due to evaporation and sublimation as long as ambient temperature stays low and no melt water runoff occurs. Short-term releases to surface waters after snowmelt initiation in spring may lead to high concentrations having an impact on water quality. To trace radionuclide transport in the aquatic environments related to snow on Mt. Zugspitze, in addition to their concentrations, comprehensive knowledge about the type of precipitation and the size of the aerosols, they are bound at, the snow cover development, the influence of meteorological conditions on snow alteration and melt water runoff are necessary. A brief description of methods for the investigation of the transport of ubiquitously distributed environmental radionuclides from their atmospheric deposition over their behaviour in the snow cover at Zugspitzplatt to the recovery in the surface water at Partnach spring is given. Applications performed in research projects of the authors’ work group since 2011 on Mt. Zugspitze are introduced and highlight the advantages of the location for studying water and radionuclide budgets related to snow. The results help to trace the pathways of radioactive particles from the atmosphere to aquatic environments. Consequently, in cases of extensive radionuclide releases to snow covered environments, peak discharges and the scope of action for countermeasures can be predicted to mitigate the impact on water quality and human radiation exposure