Journal of Atmospheric Chemistry

, Volume 22, Issue 1–2, pp 149–162 | Cite as

Methane, carbon monoxide and light non-methane hydrocarbon emissions from African savanna burnings during the FOS/DECAFE experiment

  • B. Bonsang
  • C. Boissard
  • M. F. Le Cloarec
  • J. Rudolph
  • J. P. Lacaux
Article

Abstract

Atmospheric samples from savanna burnings were collected in the Ivory Coast during two campaigns in January 1989 and January 1991. About 30 nonmethane hydrocarbons from C2 to C6, carbon monoxide, carbon dioxide and methane were measured from the background and also at various distances from the burning. Concentrations in the fire plume reached ppmv levels for C2-C4 hydrocarbons, and 5300, 500 and 93 ppmv for CO2, CO and CH4 respectively. The excess in the mixing ratios of these gases above their background level is used to derive emission factors relative to CO and CO2. For the samples collected immediately in the fire plume, a differentiation between high and low combustion efficiency conditions is made by considering the CO/CO2 ratio. Ethene (C2H4), acetylene (C2H2), ethane (C2H6) and propene (C3H6) are the major NMHC produced in the flaming stage, whereas a different pattern with an increasing contribution of alkanes is observed in samples typical of post flaming processes. A strong correlation between methane and carbon monoxide suggests that these compounds are produced during the same stage of the combustion. In samples collected at a distance from the fire and integrated over a period of 30 minutes, the composition is very similar to that of flaming. ΔNMHC/ΔCO2 is of the order of 0.7%, ΔCH4/ΔCO2 of the order of 0.4% and ΔCO/ΔCO2 of the order of 6.3%. From this study, a global production by African savanna fires is derived: 65 Tg of CO-C, 4.2 Tg of CH4-C and 6.7 Tg of NMHC-C. Whereas acetylene can be used as a conservative tracer of the fire plumes, only ethene, propene and butenes can be considered in terms of their direct photochemical impact.

Key words

biomass burning hydrocarbons methane 

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References

  1. Bonsang, B. and Lambert, G., 1985, Nonmethane hydrocarbons in an oceanic atmosphere,J. Atmos. Chem. 2, 257, 271.Google Scholar
  2. Bonsang, B., Kanakidou, M., Lambert, G., and Rudolph, J., 1988, Vertical profiles and fluxes of NMHC in the equatorial forest of Congo, AGU Fall Meeting, San Francisco, 5–9 Dec. 1988.Google Scholar
  3. Bonsang, B., Kanakidou, M., Lambert, G., and Monfray, P., 1988, The marine source of C2–C6 aliphatic hydrocarbons,J. Atmos. Chem. 6, 3–20.Google Scholar
  4. Bonsang, B., Lambert, G., and Boissard, C., 1991, Light Hydrocarbons emissions from African savanna burnings, in J. S. Levine (ed.),Global Biomass Burning, Cambridge, MA, MIT Press, pp. 155–161.Google Scholar
  5. Boissard, C., 1992, Distributions troposphériques globales des hydrocarbures légers: de l'expérimentation à la modélisation,Thèse de Doctorat en Sciences, Université de Paris VII.Google Scholar
  6. Cros, B., Delmas, R., Nganga, D., and Clairac, B., 1988, Seasonal trends of ozone in equatorial Africa: Experimental evidence of photochemical formation,J. Geophys. Res. 93, 8355–8366.Google Scholar
  7. Cros, B., Nganga, D., Delmas, R., and Fontan, J., 1991, Tropospheric ozone and biomass burning in intertropical Africa, in J. S. Levine (ed.),Global Biomass Burning, Cambridge, MA, MIT Press, pp. 143–147.Google Scholar
  8. Crutzen, P. J., Heidt, L. E., Krasnec, J. P., Pollock, W. H., and Seiler, W., 1979, Biomass burning as a source of atmospheric trace gases,Nature 282, 253–256.Google Scholar
  9. Crutzen, P. J., Delany, A. C., Greenberg, J., Haagenson, P., Heidt, L., Lueb, R., Pollock, W., Seiler, W., Wartburg, A., and Zimmerman, P., 1985, Tropospheric chemical composition measurements in Brazil during the dry season,J. Atmos. Chem. 2, 233–256.Google Scholar
  10. Crutzen, P. J., Hao, W. M., Liu, M. H., Lobert, J. M., and Scharffe, D., 1989, Emissions of CO2 and other trace gases to the atmosphere from fires in the tropics, in Crutzen, Gerard, Zander (eds.),Our Changing Atmosphere, Proceedings of the 28th Liege International Astrophysical Colloquium, 26–30 June 1989.Google Scholar
  11. Crutzen, P. J. and Andreae, M. O., 1990, Biomass burning in the tropics: impact on atmospheric chemistry and biogeochemical cycles,Science 250, 1669–1678.Google Scholar
  12. Delmas, R., Marenco, A., Tathy, J. P., Cros, B., and Baudet, J. G. R., 1991, Sources and sinks of methane in the African savanna. CH4 emissions from biomass burning,J. Geophys. Res. 96, 7287, 7299.Google Scholar
  13. Fishman, J. and Larsen, J. C., 1987, The distribution of total ozone and stratospheric ozone in the tropics: implication for the distribution of tropospheric ozone,J. Geophys. Res. 92, 6627–6634.Google Scholar
  14. Fishman, J., Fukhruzjaman, Cros, B., Nganga, D., 1991, Identification of widespread pollution in the southern hemisphere deduced from satellites analyses,Sciences 252, 1693–1696.Google Scholar
  15. Greenberg, J. P., Zimmerman, P. R., Heidt, L., and Pollock, W., 1984, Hydrocarbon and Carbon monoxide emissions from biomass burning in Brazil,J. Geophys. Res. 89, 1350–1354.Google Scholar
  16. Hao, W. M., Scharffe, D., Lobert, J. M., and Crutzen, P. J., 1990, Biomass burning: an important source of atmospheric CO CO2 and hydrocarbons, Chapman conference on global biomass burning: atmospheric, climatic and and biospheric implications, Williamsburg, USA, March 19–23.Google Scholar
  17. Hao, W. M. and Ward, D. E., 1993, Methane production from global biomass burning,J. Geophys. Res. 98, 20567, 20661.Google Scholar
  18. Helas, G., Schebeske, G., Scharffe, D., Mano, S., Andreae, M. O., Koppmann, R., Rudolph, J., De ock, A., Atlas, E., 1993, Light hydrocarbons measured over savanna fires in South Africa.Proc. of 1993 AGU Fall Meeting, December 6–10 San Francisco (U.S.A.). p. 117.Google Scholar
  19. Kanakidou, M., Bonsang, B., and Lambert, G., 1989, Light hydrocarbons vertical profiles and fluxes in a french rural area,Atmos. Environ. 23, 921–927.Google Scholar
  20. Kirchhoff, V. W. J. H., Browell, E. V., and Gregory, G. L., 1988, Ozone measurements in the troposphere of an Amazonian rain forest environment,J. Geophys. Res. 93, 850–860.Google Scholar
  21. Kirchhoff, V. W. J. H. and Rasmussen, R. A., 1990, Time variations of CO and O3 concentrations in a region subject to biomass burning,J. Geophys. Res. 95, 7521–7532.Google Scholar
  22. Lobert, J. M. and Warnatz, J., 1992, Emissions from the combustion process in vegetation, in P. J. Crutzen and J. G. Goldamer (eds.),Fire in the Environment, The Ecological, Atmospheric and Climatic Importance of Vegetation Fires, Report on the Dahlem Workshop, Berlin 15–20 March, Wiley, pp. 15–37.Google Scholar
  23. Marenco, A. and Said, F., 1989, Meridional and vertical ozone distribution in the background troposphere (70° N-60° S; 0–12 km altitude) from scientific aircraft measurements during the stratoz III experiment (June 1984),Atmos. Environ. 23, 201–214.Google Scholar
  24. Marenco, A., Macaigne, M., and Prieur, S., 1989, Meridional and vertical CO and CH4 distributions in the background troposphere (70° N-60° S; 0–12 km altitude) from scientific aircraft measurements during the STRATOZ III experiment (June 1984),Atmos. Environ. 23, 185–200.Google Scholar
  25. Marenco, A., 1992, Campagne meridienne aéroportée TROPEZ II,Rapport d'activité PACB 1992.Google Scholar
  26. Rudolph, J. and Ehhalt, D. H., 1981, Measurements of C2-C5 hydrocarbons over the North Atlantic,J. Geophys. Res. 86, 11959–11064.Google Scholar
  27. Rudolph, J., Koppmann, R., and Bonsang, B., 1988, Measurements of light hydrocarbons and carbon monoxide over an equatorial forest in Africa, AGU Fall Meeting, San Francisco, 5–9 Dec.Google Scholar
  28. Rudolph, J., Khedim, A., Bonsang, B., Helas, G., and Andreae, M. O., 1990, Hydrocarbon emission from tropical biomass burning and ozone formation, Chapman conference on global biomass burning: atmospheric, climatic and biospheric implications, Williamsburg USA, March 19–23.Google Scholar
  29. Rudolph, J., and Johnen, F.J., 1990, Measurements of light atmospheric hydrocarbons over the Atlantic in regions of low biological activity,J. Geophys. Res. 95, 20583–20591.Google Scholar
  30. Rudolph, J., Khedim, A., and Bonsang, B., 1992, Light hydrocarbons in the tropospheric boundary layer over tropical Africa,J. Geophys. Res. 97, 6181–6186.Google Scholar
  31. Rudolph, J., Khedim, A., Koppmann, R., and Bonsang, B., 1995, Field study of the emissions of methyl chloride and other halocarbons from biomass burning in equatorial Africa,J. Atmos. Chem. 22, 67–80 (this issue).Google Scholar
  32. Ward, D. E. and Radke, L. F., 1992, Emissions measurements from vegetation fires: a comparative evaluation of methods and results, in P. J. Crutzen and J. G. Goldamer,Fire in the Environment, The Ecological, Atmospheric and Climatic Importance of Vegetation Fires, Report on the Dahlem Workshop, Berlin, 15–20 March 1992, Wiley, pp. 57, 76.Google Scholar
  33. Ward, D. E., Susott, R. A., Doughty, B., Shea, R., Haskins, C., Scholes, M., Chidumayo, E., 1993, Combustion efficiency and smoke emissions from fires in selected savanna ecosystems of South Africa and Zambia. Proc. of 1993 AGU Fall Meeting, December 6–10 San Francisco (USA), p. 128.Google Scholar

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • B. Bonsang
    • 1
  • C. Boissard
    • 1
  • M. F. Le Cloarec
    • 1
  • J. Rudolph
    • 2
  • J. P. Lacaux
    • 3
  1. 1.Centre des Faibles Radioactivités, Domaine du CNRSGif-sur-YvetteFrance
  2. 2.Institüt für Atmosphärische ChemieForschungszentrum JülichJülichGermany
  3. 3.Centre de recherches atmosphériques, CampistrousLannemezanFrance

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