A simplified, data-constrained approach to estimate the permafrost carbon-climate feedback: The PCN Incubation-Panarctic Thermal (PInc-PanTher) Scaling Approach

Thursday, 17 December 2015: 12:05
2004 (Moscone West)
Charles D Koven1, Edward Schuur2, Christina Schaedel2, Theodore J Bohn3, Eleanor Burke4, Guangsheng Chen5, Xiaodong Chen6, Philippe Ciais7, Guido Grosse8, Jennifer W Harden9, Daniel J Hayes10, Gustaf Hugelius11, Elchin E Jafarov12, Gerhard Krinner13, Peter Kuhry11, David M Lawrence14, Andrew MacDougall15, Sergey S Marchenko16, Anthony David McGuire17, Susan Natali18, Dmitry Nicolsky16, David Olefeldt19, Shushi Peng7, Vladimir E Romanovsky16, Kevin M Schaefer20, Jens Strauss8, Claire C Treat16 and Merritt R Turetsky21, (1)Lawrence Berkeley National Laboratory, Berkeley, CA, United States, (2)Northern Arizona University, Flagstaff, AZ, United States, (3)Arizona State University, Tempe, AZ, United States, (4)Met Office Hadley Centre, Exeter, United Kingdom, (5)Oak Ridge National Laboratory, Oak Ridge, TN, United States, (6)University of Washington Seattle Campus, Seattle, WA, United States, (7)LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, France, (8)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Potsdam, Potsdam, Germany, (9)USGS Geological Survey, Menlo Park, CA, United States, (10)University of Maine, Orono, ME, United States, (11)Stockholm University, Stockholm, Sweden, (12)Institute of Arctic and Alpine Research, Boulder, CO, United States, (13)LGGE Laboratoire de Glaciologie et Géophysique de l’Environnement, Saint Martin d'Hères, France, (14)National Center for Atmospheric Research, Boulder, CO, United States, (15)University of Victoria, Victoria, BC, Canada, (16)University of Alaska Fairbanks, Fairbanks, AK, United States, (17)University of Alaska Fairbanks, Institute of Arctic Biology, Fairbanks, AK, United States, (18)Woods Hole Science Center Falmouth, Falmouth, MA, United States, (19)University of Alberta, Edmonton, AB, Canada, (20)University of Colorado, National Snow and Ice Data Center, Boulder, CO, United States, (21)University of Guelph, Guelph, ON, Canada
We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after thaw; and models of soil thermal dynamics in response to climate warming. We call the approach the Permafrost Carbon Network Incubation–Panarctic Thermal scaling approach (PInc–PanTher). The approach assumes that C stocks do not decompose at all when frozen, but once thawed follow set decomposition trajectories as a function of soil temperature. The trajectories are determined according to a 3-pool decomposition model fitted to incubation data using parameters specific to soil horizon types. We calculate litterfall C inputs required to maintain steady-state C balance for the current climate, and hold those inputs constant. Soil temperatures are taken from the soil thermal modules of ecosystem model simulations forced by a common set of future climate change anomalies under two warming scenarios over the period 2010 to 2100.