1. Department of Physical Geography and Ecosystem ScienceLund University Lund Sweden
2. Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource ManagementUniversity of Copenhagen Copenhagen Denmark
3. Rossby CentreSwedish Meteorological and Hydrological Institute Norrköping Sweden
4. Environmental Sciences Division and Climate Change Science InstituteOak Ridge National Laboratory Oak Ridge TN USA