Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River Delta M. Langer, S. Westermann, K. M. Walter Anthony, K. Wischnewski, and J. Boike Alfred-Wegener-Institut Helmholtz-Zentrum für Polarund Meeresforschung, Periglacial Research Section, Potsdam, Germany University of Oslo, Department of Geography, Oslo, Norway Ce...