Isotopic Ratios of Tropical Methane Emissions by Atmospheric Measurement

Rebecca Brownlow, David Lowry, Rebecca Fisher, James France, Mathias Lanoiselle, Barbara White, Martin Wooster, Zhang T, Euan Nisbet

Research output: Contribution to journalArticlepeer-review

Abstract

Tropical methane sources are an important part of the global methane budget and include natural wetlands, rice agriculture, biomass burning, ruminants, fossil fuels and waste. δ13CCH4 can provide strong constraints on methane source apportionment. For example, tropical wetlands in this study give δ13CCH4 values between -61.5 ±2.9 ‰ and -53.0 ±0.4 ‰ and in general are more enriched in 13C than temperate and boreal wetlands. However, thus far, relatively few measurements of δ13CCH4 in methane-enriched air have been made in the tropics. In this study samples have been collected from tropical wetland, rice, ruminant, and biomass burning emissions to the atmosphere. Regional isotopic signatures vary greatly as different processes and source material affect methane signatures. Measurements were made to determine bulk source inputs to the atmosphere, rather than to study individual processes. These measurements provide inputs for regional methane budget models, to constrain emissions with better source apportionment.
Original languageEnglish
Pages (from-to)1408-1419
Number of pages12
JournalGlobal Biogeochemical Cycles
Volume31
Issue number9
Early online date4 Sept 2017
DOIs
Publication statusPublished - Sept 2017

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