Purdue Climate Change Research Center

Synthesis of Arctic System Carbon Cycle Research through Model-Data Fusion Studies Using Atmospheric Inversion and Process-Based Approaches

Funded by the National Science Foundation

To improve how we simulate and predict carbon dynamics in high latitudes, this project seeks to comprehensively analyze the carbon cycle of the Arctic system. An important factor to consider is wildfire frequency, and the team has made progress in this area, as reported in their paper, “Characterization of Wildfire Regimes in Canadian Boreal Terrestrial Ecosystems.” The authors find that regional wildfires exhibit a robust power law relationship between the number of fires and burn area, which allowed for the estimation of fire return intervals for each spatial unit (ecozone).

Using a biogeochemistry model (the Terrestrial Ecosystem Model), the team also estimated net methane emissions from Arctic wetlands. Emissions from the entire Pan-Arctic region (45oN) during the period 1996-2006 were 51 Tg CH4/year, with emissions of 11 Tg CH4/year from Boreal North America and 29 Tg CH4/year from Boreal Asia. The Arctic Basin releases approximately 38 Tg CH4/year to the atmosphere, and the emissions grew on average by 0.5 Tg CH4/year over the decade of analysis. Terrestrial methane emissions due to wildfires were 3.5 and 5 Tg CH4/year for the Basin and the Pan-Arctic region, respectively. There is significant interannual variation in total emissions over the simulation period, with a peak in 1998 and the lowest emissions in 1997. In Boreal Asia, there is an increase trend while the emissions are stable in Boreal North America since 2001. Peak methane emissions consistently occur in July for the whole Pan-Arctic region. These process model simulations are in agreement with estimates obtained using a 3D inverse model methodology for the North American and Eurasian Arctic sectors.


  • Qianlai Zhuang, EAS and Agronomy
  • University of Alaska, Fairbanks
  • J. Melillo, Marine Biological Laboratory
  • M. Follows, Massachusetts Institute of Technology

Contact Information

Purdue University
203 S. Martin Jischke Drive
MANN 105
West Lafayette, IN 47907