Chapter 8 Permafrost – Physical Aspects, Carbon Cycling, Databases and Uncertainties

• Main Authors: Julia Boike, Moritz Langer, Hugues Lantuit, Sina Muster, A. David Mcguire, J. Boike, M. Langer, H. Lantuit, S. Muster, P. Overduin, K. Roth, T. Sachs, S. Westermann, A. D. Mcguire
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: models • Soil organic matter • Soil organic carbon • Methane • Active layer; permafrost; Thermokarst
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.296.7690; http://www.lter.uaf.edu/pdf/1626_Boike_Langer_2012.pdf

Abstract Permafrost is defined as ground that remains below 0°C for at least 2 consecutive years. About 24 % of the northern hemisphere land area is underlain by permafrost. The thawing of permafrost has the potential to influence the climate system through the release of carbon (C) from northern high latitude terrestrial ecosystems, but there is substantial uncertainty about the sensitivity of the C cycle to thawing permafrost. Soil C can be mobilized from permafrost in response to changes in air temperature, directional changes in water balance, fire, thermokarst, and flooding. Observation networks need to be implemented to understand responses of permafrost and C at a range of temporal and spatial scales. The understanding