Isotopic signatures of methane emissions from tropical fires, agriculture and wetlands: the MOYA and ZWAMPS flights.

Autor: Nisbet EG; Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK., Allen G; Centre for Atmospheric Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK., Fisher RE; Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK., France JL; Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK.; British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, UK., Lee JD; National Centre for Atmospheric Sciences, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK., Lowry D; Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK., Andrade MF; Laboratory for Atmospheric Physics, Institute for Physics Research, Universidad Mayor de San Andrés-UMSA, Campus Universitario, Cota-Cota Calle No 27, La Paz, Bolivia.; Department Atmospheric and Oceanic Sciences, University of Maryland, College Park, MD 20742, USA., Bannan TJ; Centre for Atmospheric Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK., Barker P; Centre for Atmospheric Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK., Bateson P; Centre for Atmospheric Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK., Bauguitte SJ; Facility for Airborne Atmospheric Measurement, Cranfield University, College Road, Cranfield MK43 0AL, UK., Bower KN; Centre for Atmospheric Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK., Broderick TJ; 19 Jenkinson Road, Chisipite, Harare, Zimbabwe., Chibesakunda F; Geological Survey of Zambia, Ministry of Mines and Mineral Development, PO Box 50135, Ridgeway, Lusaka, Zambia., Cain M; Centre for Environment and Agricultural Informatics, Cranfield University, College Road, Cranfield MK43 0AL, UK., Cozens AE; Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK., Daly MC; Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK., Ganesan AL; School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK., Jones AE; British Antarctic Survey, Natural Environment Research Council, Cambridge CB3 0ET, UK., Lambakasa M; Geological Survey of Zambia, Ministry of Mines and Mineral Development, PO Box 50135, Ridgeway, Lusaka, Zambia., Lunt MF; School of GeoSciences, University of Edinburgh, Edinburgh EH9 3FF, UK., Mehra A; Centre for Atmospheric Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK.; Now at Faculty of Science and Engineering, University of Chester, Chester, UK., Moreno I; Laboratory for Atmospheric Physics, Institute for Physics Research, Universidad Mayor de San Andrés-UMSA, Campus Universitario, Cota-Cota Calle No 27, La Paz, Bolivia., Pasternak D; National Centre for Atmospheric Sciences, Department of Chemistry, University of York, Heslington, York YO10 5DD, UK.; Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, UK., Palmer PI; School of GeoSciences, University of Edinburgh, Edinburgh EH9 3FF, UK.; National Centre for Earth Observation, University of Edinburgh, Edinburgh EH9 3FF, UK., Percival CJ; Now at Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA., Pitt JR; School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA., Riddle AJ; Department of Earth Sciences, Royal Holloway, University of London, Egham TW20 0EX, UK., Rigby M; School of Chemistry, University of Bristol, Bristol BS8 1TS, UK., Shaw JT; Centre for Atmospheric Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK., Stell AC; School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK., Vaughan AR; Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, UK., Warwick NJ; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK., E Wilde S; Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York YO10 5DD, UK.
Jazyk: angličtina
Zdroj: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences [Philos Trans A Math Phys Eng Sci] 2022 Jan 24; Vol. 380 (2215), pp. 20210112. Date of Electronic Publication: 2021 Dec 06.
DOI: 10.1098/rsta.2021.0112
Abstrakt: 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 δ 13 C CH 4 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 δ 13 C CH 4 signatures were measured over the Amazonian wetlands of NE Bolivia (around -59‰) and the overall δ 13 C CH 4 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, δ 13 C CH 4 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, δ 13 C CH 4 values were around -28‰. By contrast, African C4 tropical grass fire δ 13 C CH 4 values were -16 to -12‰. Methane from urban landfills in Zambia and Zimbabwe, which have frequent waste fires, had δ 13 C CH 4 around -37 to -36‰. These new isotopic values help improve isotopic constraints on global methane budget models because atmospheric δ 13 C CH 4 values predicted by global atmospheric models are highly sensitive to the δ 13 C CH 4 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)'.
Databáze: MEDLINE