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Title: WETCHIMP-WSL: Intercomparison of wetland methane emissions models over West Siberia

Wetlands are the world's largest natural source of methane, a powerful greenhouse gas. The strong sensitivity of methane emissions to environmental factors such as soil temperature and moisture has led to concerns about potential positive feedbacks to climate change. This risk is particularly relevant at high latitudes, which have experienced pronounced warming and where thawing permafrost could potentially liberate large amounts of labile carbon over the next 100 years. However, global models disagree as to the magnitude and spatial distribution of emissions, due to uncertainties in wetland area and emissions per unit area and a scarcity of in situ observations. Recent intensive field campaigns across the West Siberian Lowland (WSL) make this an ideal region over which to assess the performance of large-scale process-based wetland models in a high-latitude environment. Here we present the results of a follow-up to the Wetland and Wetland CH4 Intercomparison of Models Project (WETCHIMP), focused on the West Siberian Lowland (WETCHIMP-WSL). We assessed 21 models and 5 inversions over this domain in terms of total CH4 emissions, simulated wetland areas, and CH4 fluxes per unit wetland area and compared these results to an intensive in situ CH4 flux data set, several wetland maps, and twomore » satellite surface water products. We found that (a) despite the large scatter of individual estimates, 12-year mean estimates of annual total emissions over the WSL from forward models (5.34 ± 0.54 Tg CH4 yr⁻¹), inversions (6.06 ± 1.22 Tg CH4 yr⁻¹), and in situ observations (3.91 ± 1.29 Tg CH4 yr⁻¹) largely agreed; (b) forward models using surface water products alone to estimate wetland areas suffered from severe biases in CH4 emissions; (c) the interannual time series of models that lacked either soil thermal physics appropriate to the high latitudes or realistic emissions from unsaturated peatlands tended to be dominated by a single environmental driver (inundation or air temperature), unlike those of inversions and more sophisticated forward models; (d) differences in biogeochemical schemes across models had relatively smaller influence over performance; and (e) multiyear or multidecade observational records are crucial for evaluating models' responses to long-term climate change.« less
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [4] ;  [12] ;  [13] ;  [14] ;  [15] ;  [16] ;  [17] ;  [18] ;  [18] more »;  [7] ;  [19] ;  [20] « less
  1. Arizona State Univ., Tempe, AZ (United States)
  2. Canadian Centre for Climate Modelling and Analysis, Victoria (Canada)
  3. National Institute for Environmental Studies, Tsukuba (Japan)
  4. Max Planck Institute for Meteorology, Hamburg (Germany)
  5. Univ. of Bern, Bern (Switzerland)
  6. Univ. of Bern, Bern (Switzerland); Imperial College, Ascot (United Kingdom)
  7. Auburn Univ., Auburn, AL (United States)
  8. Purdue Univ., West Lafayette, IN (United States); Colorado State Univ., Fort Collins, CO (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  9. City Univ. of New York, New York, NY (United States); Univ. of Hohenheim, Stuttgart (Germany)
  10. Moscow State Univ., Moscow (Russian Federation); Russain Academy of Sciences, Uspenskoe (Russia); Tomsk State Univ., Tomsk (Russia); Yugra State Univ., Khanty-Mantsiysk (Russia)
  11. National Institute for Environmental Studies, Tsukuba (Japan); Tomsk State Univ., Tomsk (Russia)
  12. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  13. Russian Academy of Sciences (RAS), Moscow (Russian Federation)
  14. Russian Academy of Sciences (RAS), Moscow (Russian Federation); Kazan Federal Univ., Kazan (Russia)
  15. Univ. of Exeter, Exeter (United Kingdom)
  16. City Univ. of New York, New York, NY (United States)
  17. Univ. of Massachusetts, Amherst, MA (United States)
  18. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
  19. Purdue Univ., West Lafayette, IN (United States)
  20. Univ. of Lausanne, Lausanne (Switzerland)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
SC0007007; AC02-05CH11231
Accepted Manuscript
Journal Name:
Biogeosciences (Online)
Additional Journal Information:
Journal Name: Biogeosciences (Online); Journal Volume: 12; Journal Issue: 11; Journal ID: ISSN 1726-4189
European Geosciences Union
Research Org:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Org:
Country of Publication:
United States