Permafrost Carbon Network

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Working Group: Upscaling and Modeling of Permafrost Carbon

Background and Objectives:

Important insights about the impact of carbon release from permafrost thaw on future climate have been derived from uncoupled dynamic ecosystem model and coupled carbon-climate model simulations, but there is still a great deal of uncertainty on the future rate of permafrost degradation in response to climate warming. Moreover, our understanding of the responses of the coupled hydrological and carbon cycles to permafrost degradation across spatial and temporal scales is very limited, as is our predictive capability regarding the resulting changes to biogeochemical cycles. Earth System Model (ESM) simulations have suggested that substantial permafrost thaw could happen during the 21st Century, but these results have been controversial due to structural limitations in the class of land models used in ESMs and due to biases in simulated soil temperatures associated with ESM climate biases.

 

Key questions we are adressing in the Model Integration working group are:

  • The need to assess the current state of the models that are attempting to represent permafrost and the interactions among permafrost, hydrology, carbon, and nitrogen dynamics

  • The need to conduct a state-of-the-art assessment on the vulnerability of permafrost carbon that could tie into the IPCC process

  • The production of a synthesis paper on conceptual approaches that should be embraced by coupled permafrost-carbon models.


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    Completed synthesis Products

    Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009

    This project evaluates model projections of vulnerability of the permafrost region by comparing 15 land surface model simulations including carbon cycle processes and permafrost for two time periods. Results from this model intercomparison help evaluate how differences in model structure and parameterization influence projected uptake and release of carbon for the permafrost region in the current and future climate.

    McGuire AD, Koven C, Lawrence DM, Clein JS, Xia J, Beer C, Burke E, Chen G, Chen X, Delire C, Jafarov E, MacDougall AH, Marchenko S, Nicolsky D, Peng S, Rinke A, Saito K, Zhang W, Alkama R, Bohn TJ, Ciais P, Decharme B, Ekici A, Gouttevin I, Hajima T, Hayes DJ, Ji D, Krinner G, Lettenmaier DP, Luo Y, Miller PA, Moore JC, Romanovsky V, Schädel C, Schaefer K, Schuur EAG, Smith B, Sueyoshi T, Zhuang Q (2016) Variability in the sensitivity among model simulations of permafrost and carbon dynamics in the permafrost region between 1960 and 2009. Global Biogeochemical Cycles. doi:10.1002/2016GB005405

     

    A simplified, data-constrained approach to estimate the permafrost carbon–climate feedback

    A team of researchers developed a model that accounts for the atmospheric effect of emissions released from carbon sequestered in thawing permafrost. Compared with Earth system models, which consider much larger amounts of information in a global system, the research team used a simpler model, aiming to find clearer connections between the specific data entered and resulting projections. This modeling approach was highly data-constraint using data from recent syntheses from the Permafrost Carbon Network

    Koven CD, Schuur EAG, Schädel C, Bohn TJ, Burke EJ, Chen G, Chen X, Ciais P, Grosse G, Harden JW, Hayes DJ, Hugelius G, Jafarov EE, Krinner G, Kuhry P, Lawrence DM, Macdougall AH, Marchenko SS, Mcguire AD, Natali SM, Nicolsky DJ, Olefeldt D, Peng S, Romanovsky VE, Schaefer KM, Strauss J, Treat CC, Turetsky M (2015) A simplified, data-constrained approach to estimate the permafrost carbon–climate feedback. Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 373, DOI: 10.1098/rsta.2014.0423


     

    Model Integration products in progress:

    Assessment of the vulnerability of permafrost carbon to projected climate change: A sensitivity analysis among large-scale process-based models. This activity is a comparison of how large-scale models represent permafrost carbon dynamics into the future (2010 – 2299). We are evaluating model sensitivity to spatial and temporal variation in projected climate change.

    Leads: A. David McGuire, David Lawrence

     

    Permafrost Regionalization Map (PeRM) The permafrost regionalization map is an integrated effort that aims to identify and characterize the key environmental controls on carbon vulnerability among different geographic regions across the northern permafrost domain. The map was developed based on the circum-arctic permafrost and ground ice condition map by Brown et al. (1997) and circum-arctic vegetation map developed by Walker et al. (2005). The permafrost regions were defined using different parameters including topography, geographical locations (continentality), types of permafrost present, types of biomes and arctic bioclimatic zones and predominant terrain types. The PeRM will have many uses for the researchers within the RCN and beyond - including data synthesis, model-data integration and model benchmarking - to contribute to an improved understanding of the vulnerability of the permafrost carbon pool to climate change and the implications to the global carbon budget. 

    Leads: Daniel Hayes

     

    For more details on this working group send an email to David A. McGuire

     

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