Isotopic Signatures of Methane Emissions from Tropical Fires, Agriculture and Wetlands: The MOYA and ZWAMPS Flights
Authors
Nisbet, Euan G.Allen, Grant
Fisher, Rebecca E.
France, James L.
Lee, James D.
Lowry, David
Andrade, Marcos F.
Bannan, Thomas J.
Barker, Patrick
Bateson, Prudence
Bauguitte, Stéphane J.-B.
Bower, Keith N.
Broderick, Tim J.
Chibesakunda, Francis
Cain, Michelle
Cozens, Alice E.
Daly, Michael C.
Ganesan, Anita L.
Jones, Anna E.
Lambakasa, Musa
Lunt, Mark F.
Mehra, Archit
Moreno, Isabel
Pasternak, Dominika
Palmer, Paul I.
Percival, Carl J.
Pitt, Joseph R.
Riddle, Amber J.
Rigby, Matthew
Shaw, Jacob T.
Stell, Angharad C.
Vaughan, Adam R.
Warwick, Nicola J.
Wilde, Shona E.
Affiliation
University of London; University of Manchester; University of York; Universidad Mayor de San Andrés-UMSA; Cranfield University; Geological Survey of Zambia; University of Oxford; University of Bristol; University of Edinburgh; Stony Brook University; University of Cambridge; California Institute of Technology; British Antarctic Survey, Natural Environment Research Council, Cambridge; University of Maryland; University of ChesterPublication Date
2021-12-06
Metadata
Show full item recordAbstract
We report methane isotopologue data from aircraft and ground measurements in Africa and South America. Aircraft campaigns sampled strong methane fluxes over tropical papyrus wetlands in the Nile, Congo and Zambezi basins, herbaceous wetlands in Bolivian southern Amazonia, and over fires in African woodland, cropland and savannah grassland. Measured methane δ13CCH4 isotopic signatures were in the range −55 to −49‰ for emissions from equatorial Nile wetlands and agricultural areas, but widely −60 ± 1‰ from Upper Congo and Zambezi wetlands. Very similar δ13CCH4 signatures were measured over the Amazonian wetlands of NE Bolivia (around −59‰) and the overall δ13CCH4 signature from outer tropical wetlands in the southern Upper Congo and Upper Amazon drainage plotted together was −59 ± 2‰. These results were more negative than expected. For African cattle, δ13CCH4 values were around −60 to −50‰. Isotopic ratios in methane emitted by tropical fires depended on the C3 : C4 ratio of the biomass fuel. In smoke from tropical C3 dry forest fires in Senegal, δ13CCH4 values were around −28‰. By contrast, African C4 tropical grass fire δ13CCH4 values were −16 to −12‰. Methane from urban landfills in Zambia and Zimbabwe, which have frequent waste fires, had δ13CCH4 around −37 to −36‰. These new isotopic values help improve isotopic constraints on global methane budget models because atmospheric δ13CCH4 values predicted by global atmospheric models are highly sensitive to the δ13CCH4 isotopic signatures applied to tropical wetland emissions. Field and aircraft campaigns also observed widespread regional smoke pollution over Africa, in both the wet and dry seasons, and large urban pollution plumes. The work highlights the need to understand tropical greenhouse gas emissions in order to meet the goals of the UNFCCC Paris Agreement, and to help reduce air pollution over wide regions of Africa. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 2)'.Citation
Nisbet, E. G., Allen, G., Fisher, R. E., France, J. L., Lee, J. D., Lowry, D., Andrade, M. F., Bannan, T. J., Barker, P., Bateson, P., Bauguitte, S. J.-B., Bower, K. N., Broderick, T. J., Chibesakunda, F., Cain, M., Cozens, A. E., Daly, M. C., Ganesan, A. L., Jones, A. E., ... Wilde, S. E. (2022). Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 380(2215), 20210112. https://doi.org/10.1098/rsta.2021.0112Publisher
The Royal SocietyJournal
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering SciencesType
ArticleDescription
© 2021 The Authors.ISSN
1364-503XEISSN
1471-2962Sponsors
Funder: Natural Environment Research Council; Id: http://dx.doi.org/10.13039/501100000270; Grant(s): NE/N016238/1 MOYA The Global Methane Budget, NE/P019641/1 New methodologies for removal of meth, NE/S00159X/1 ZWAMPS Quantifying Methane Emissionsae974a485f413a2113503eed53cd6c53
10.1098/rsta.2021.0112
Scopus Count
Collections
Except where otherwise noted, this item's license is described as Licence for VoR version of this article: http://creativecommons.org/licenses/by/4.0/