Large-Scale Controls of Methanogenesis Inferred from Methane and Gravity Spaceborne Data
Wetlands are the largest individual source of methane (CH_4), but the magnitude and distribution of this source are poorly understood on continental scales. We isolated the wetland and rice paddy contributions to spaceborne CH_4 measurements over 2003–2005 using satellite observations of gravity ano...
| Published in: | Science |
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| Main Authors: | , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
American Association for the Advancement of Science
2010
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| Subjects: | |
| Online Access: | https://authors.library.caltech.edu/57435/ https://authors.library.caltech.edu/57435/2/Bloom.SOM.pdf https://resolver.caltech.edu/CaltechAUTHORS:20150512-091007483 |
| Summary: | Wetlands are the largest individual source of methane (CH_4), but the magnitude and distribution of this source are poorly understood on continental scales. We isolated the wetland and rice paddy contributions to spaceborne CH_4 measurements over 2003–2005 using satellite observations of gravity anomalies, a proxy for water-table depth Γ, and surface temperature analyses T_S. We find that tropical and higher-latitude CH_4 variations are largely described by Γ and T_S variations, respectively. Our work suggests that tropical wetlands contribute 52 to 58% of global emissions, with the remainder coming from the extra-tropics, 2% of which is from Arctic latitudes. We estimate a 7% rise in wetland CH_4 emissions over 2003–2007, due to warming of mid-latitude and Arctic wetland regions, which we find is consistent with recent changes in atmospheric CH_4. |
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