Collaborative Research:
Biomass Burning Emissions Over Southern Africa
Paul J. Crutzen1,2,
Jürgen M. Lobert1,4,
William C. Keene3
1Scripps Institution of Oceanography, 8605 La Jolla Shores Drive, La Jolla, CA 92037, USA
2Max Planck Institut für Chemie, Airchemistry, Becherweg 27, 55122 Mainz, Germany
3Department of Environmental Sciences, University of Virginia, Clark Hall, Charlottesville, VA 22903, USA
4Now at: Entegris, Inc., Analytical Services, 10 Forge Park, Franklin, MA 02038, USA
Biomass burning is a major source for atmospheric pollution over southern Africa as well as globally (e.g. Crutzen et al, 1979; Crutzen and Andreae, 1990). Biomass burning from the African continent currently accounts for about 35% to the global total (Logan and Yevich cited in: Lobert et al, 1999) and substantial absolute and percentage increases are projected for the future based on demographic predictions (Crutzen and Andreae, 1990, Lelieveld et al., 1998). Biomass burning emits a large variety of gaseous and particulate compounds with significant implications to atmospheric and biogeochemical cycles. Consequently, quantification of biomass burning emissions is essential for understanding and predicting associated environmental impacts. However, despite intense scientific study over the past two decades, global and regional emissions of some compounds are still poorly constrained.
We propose a 2-year investigation of biomass burning over southern Africa as part of the SAFARI-2000 campaign based on a coupled analysis of biomass composition, emission measurements, and mass-balance calculations for representative vegetation types. Biofuels will be sampled by collaborating SAFARI-2000 investigators during the dry season of 2000 in three regions of southern Africa that are representative for major ecosystem types: The Etosha National Park in northern Namibia, the Kruger National Park in north-east South Africa and woodland sites in Zambia, Malawi, Tanzania, Zimbabwe and Mozambique (the Miombo Network).
Experimental fires will be conducted at the beginning of 2001 utilizing an existing facility at the Max Planck Institute for Chemistry, Mainz, Germany. This facility had been established by P.J. Crutzen and J.M. Lobert (Lobert 1989, Lobert et al. 1990, 1991) and has been used by many other researchers. It provides a partially controlled burning environment and will be used to measure major exhaust species (CO2; CO; CH3Cl, CH3Br, CH3I; NOX; N2O; CH4; NH3; HCl, HNO3; SO2, HCOOH, CH3COOH; alkaline-reactive, volatile Cl, Br and I; the ionic composition of particles including Cl-, Br-, NO3-, SO42-, HCOOH, CH3COOH; and the elemental composition of particles including C, N, Cl, Br, I, S) as well as the elemental content of both biofuels and ash-residues. These analyses will provide for a partial or full balance for fuel carbon, nitrogen, sulfur, chlorine, bromine and possibly iodine. Sampling and analytical techniques will include canister samples, mist chambers, filter-pack sampling and continuous online sampling as well as non-dispersive infrared and chemoluminescence detection, gas chromatography / mass spectrometry, ion chromatography and other methods. Emissions will be interpreted based on a mass balance for fuel carbon, nitrogen, sulfur, chlorine, bromine, and possibly iodine.
Results will be integrated with those from other SAFARI-2000 investigators to model regional biomass burning emissions of halogen-, nitrogen-, sulfur-, carbon-containing compounds. This study will provide hitherto unavailable resolution in our ability to predict these fluxes and to assess associated regional and global implications.
Full proposal text, scientific portion only (370 kb)