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 Jafarov1, Kevin Schaefer1 and Jennifer Watts2

1National Snow and Ice Data Center, CIRES, University of Colorado Boulder 2Flathead Lake Biological Station, University of Montana

May 20, 2014

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Permafrost Permafrost Carbon Feedback Permafrost Distribution Ground temperature schematics Secondary source: Schuur et al. (2008)

Permafrost spatial distribution

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Permafrost Permafrost Carbon Feedback Permafrost Distribution Ground temperature schematics

Schematic representation of permafrost temperature

http://en.wikipedia.org/wiki/Active_layer 3 / 13

Permafrost Permafrost Carbon Feedback Overview Challenges Method Results Conclusions

Permafrost Carbon Feedback

Schaefer et al., 2012. Policy Implications of Warming Permafrost. 4 / 13

Permafrost Permafrost Carbon Feedback Overview Challenges Method 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

Permafrost Permafrost Carbon Feedback Overview Challenges Method Results Conclusions

Global Permafrost Area CMIP5

Koven et al., (2013) 6 / 13

Permafrost Permafrost Carbon Feedback Overview Challenges Method 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

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Permafrost Permafrost Carbon Feedback Overview Challenges Method Results Conclusions

100 200 300 400 500 600 700

NCSCDv2 Circumarctic 100cm SOCC 05deg

120oW 60oW 0o 60oE 120oE 180oW 54oN 63oN 72oN 81oN

Initialization of the Soil Carbon

Soil organic carbon storage up to 1 m depth in kg · C · m−2 (Hugelius et al., 2013). 8 / 13

Permafrost Permafrost Carbon Feedback Overview Challenges Method Results Conclusions

SiBCASA Terrestrial Ecosystem Model

Schaefer et al., (2008) 9 / 13

Permafrost Permafrost Carbon Feedback Overview Challenges Method Results Conclusions

1800 1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 5 6 7 8 9 10 11 12 13 14 15 time[years] million of km2 MPI−ESM−LR RCP45 RCP85

Permafrost area extent modeled by the SiBCASA model

The near-surface (up to 2m) permafrost extent driven by historical datasets and trends from MPI-ESM-LR climate model. 10 / 13

Permafrost Permafrost Carbon Feedback Overview Challenges Method Results Conclusions

1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 50 100 150 200 250 Time [years] Cumulative Perm Flux [Gt C] RCP4.5 PRC8.5

Total Cumulative Permafrost Carbon Flux

After a year 2100 the carbon flux indicate ∼50% of carbon release for RCP45 and ∼76% release of carbon for RCP85. 11 / 13

Permafrost Permafrost Carbon Feedback Overview Challenges Method Results Conclusions

1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 −200 −150 −100 −50 50 Time [years] Cumulative Net Ecosystem Exchange [Gt C] RCP4.5 with PCF RCP8.5 with PCF RCP4.5 without PCF RCP8.5 without PCF

Total Cumulative NEE

Total cumulative NEE for RCP45 and RCP85 with and without permafrost carbon flux. The gray bars represent uncertainties. 12 / 13

Permafrost Permafrost Carbon Feedback Overview Challenges Method 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

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