Evaluation of wetland methane emissions across North America using atmospheric data and inverse modeling
Existing estimates of methane (CH<sub>4</sub>) fluxes from North American wetlands vary widely in both magnitude and distribution. In light of these differences, this study uses atmospheric CH<sub>4</sub> observations from the US and Canada to analyze seven different bottom-u...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-03-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/13/1329/2016/bg-13-1329-2016.pdf |
| Summary: | Existing estimates of methane (CH<sub>4</sub>) fluxes from North American wetlands vary widely
in both magnitude and distribution. In light of these differences, this
study uses atmospheric CH<sub>4</sub> observations from the US and Canada to analyze
seven different bottom-up, wetland CH<sub>4</sub> estimates reported in a recent
model comparison project. We first use synthetic data to explore whether wetland CH<sub>4</sub> fluxes are
detectable at atmospheric observation sites.
We find that the observation network can detect aggregate wetland fluxes from both eastern and western
Canada but generally not from the US. Based upon these results, we then use real data and inverse modeling
results to analyze the magnitude, seasonality, and spatial distribution of each model estimate. The magnitude
of Canadian fluxes in many models is larger than indicated by atmospheric observations. Many models predict a
seasonality that is narrower than implied by inverse modeling results, possibly indicating an oversensitivity to
air or soil temperatures. The LPJ-Bern and SDGVM models have a
geographic distribution that is most consistent with atmospheric observations, depending upon the region and season.
These models utilize land cover maps or dynamic modeling to estimate
wetland coverage while most other models rely primarily on remote sensing inundation data. |
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| ISSN: | 1726-4170 1726-4189 |