Estimation of the Permafrost Carbon Feedback Using The SiBCASA - PowerPoint PPT Presentation

Permafrost Permafrost Carbon Feedback Estimation of the Permafrost Carbon Feedback Using The SiBCASA Terrestrial Carbon Cycle Model Elchin Jafarov 1 , Kevin Schaefer 1 and Jennifer Watts 2 1 National Snow and Ice Data Center, CIRES, University of Colorado Boulder 2 Flathead Lake Biological Station, University of Montana May 20, 2014 1 / 13

Permafrost Permafrost Distribution Permafrost Carbon Feedback Ground temperature schematics Permafrost spatial distribution Secondary source: Schuur et al. (2008) 2 / 13

Permafrost Permafrost Distribution Permafrost Carbon Feedback Ground temperature schematics Schematic representation of permafrost temperature http://en.wikipedia.org/wiki/Active_layer 3 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Permafrost Carbon Feedback Schaefer et al., 2012. Policy Implications of Warming Permafrost. 4 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Permafrost Carbon Feedback previous studies [Schaefer et al., 2014]. The ensemble mean estimate is 120 ± 89 Gt of carbon by 2100. 5% to 39% of anthropogenic emissions 5 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Global Permafrost Area CMIP5 Koven et al., (2013) 6 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Challenges in quantifying PCF 1. Initialization of frozen carbon 2. Frozen biogeochemistry 3. Soil development process (simulation of the soil organic layer) 4. Representation of methane emission from wetlands 7 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Initialization of the Soil Carbon NCSCDv2 Circumarctic 100cm SOCC 05deg 0 o 54 o N 700 60 o E 60 o W 63 o N 600 72 o N 500 81 o N 400 300 120 o W 120 o E 200 100 0 180 o W Soil organic carbon storage up to 1 m depth in kg · C · m − 2 (Hugelius et al., 2013). 8 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions SiBCASA Terrestrial Ecosystem Model Schaefer et al., (2008) 9 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Permafrost area extent modeled by the SiBCASA model MPI−ESM−LR 15 14 13 12 11 million of km 2 10 9 8 7 RCP45 6 RCP85 5 1800 1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 time[years] The near-surface (up to 2m) permafrost extent driven by historical datasets and trends from MPI-ESM-LR climate model. 10 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Total Cumulative Permafrost Carbon Flux 250 RCP4.5 PRC8.5 200 Cumulative Perm Flux [Gt C] 150 100 50 0 1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 Time [years] After a year 2100 the carbon flux indicate ∼ 50% of carbon release for RCP45 and ∼ 76% release of carbon for RCP85. 11 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Total Cumulative NEE 50 Cumulative Net Ecosystem Exchange [Gt C] 0 −50 −100 −150 RCP4.5 with PCF RCP8.5 with PCF RCP4.5 without PCF RCP8.5 without PCF −200 1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 Time [years] Total cumulative NEE for RCP45 and RCP85 with and without permafrost carbon flux. The gray bars represent uncertainties. 12 / 13

Overview Challenges Permafrost Method Permafrost Carbon Feedback Results Conclusions Conclusions 1. Our preliminary results indicate 50 Gt of carbon release for both RCPs by a year 2100, and 100 Gt for RCP45, and 220 Gt for RCP85 by a year 2300 with 25% of the initial bias. 2. Most of the permafrost carbon releases after 2100, which changes the Arctic from sink to source. 3. Introduction of the dynamic organic layer into the SibCasa’s soil model improves the overall permafrost thermal dynamics 4. Work is needed to better address methane emission from wetlands and reduce cumulative permafrost carbon flux bias 13 / 13