1. Laboratory of Environmental ChemistryPaul Scherrer Institute Villigen Switzerland
2. Department of Chemistry and BiochemistryUniversity of Bern Bern Switzerland
3. Oeschger Centre for Climate Change ResearchUniversity of Bern Bern Switzerland
4. WSL‐Institute for Snow and Avalanche Research SLF Davos Dorf Switzerland
5. Department of Environmental Systems ScienceETH Zurich Zürich Switzerland