Airborne measurements of carbonaceous aerosols in southern Africa during the dry, biomass burning season
Particulate matter collected aboard the University of Washington's Convair-580 research aircraft over southern Africa during the dry, biomass burning season was analyzed for total carbon, organic carbon, and black carbon contents using thermal and optical methods. Samples were collected in smoke plumes of burning savanna and in regional haze. A known artifact, produced by the adsorption of organic gases on the quartz filter substrates used to collect the particulate matter samples, comprised a significant portion of the total carbon collected. Consequently, conclusions derived from the data are greatly dependent on whether or not organic carbon concentrations are corrected for this artifact. For example, the estimated aerosol co-albedo (1 - single scattering albedo), which is a measure of aerosol absorption, of the biomass smoke samples is 60 percent larger using corrected organic carbon concentrations. Thus, the corrected data imply that the biomass smoke is 60 percent more absorbing than do the uncorrected data. The black carbon to (corrected) organic carbon mass ratio (BC/OC) of smoke plume samples (0.18/2610.06) is lower than that of samples collected in the regional haze (0.25/2610.08). The difference may be due to mixing of biomass smoke with background air characterized by a higher BC/OC ratio. A simple source apportionment indicates that biomass smoke contributes about three-quarters of the aerosol burden in the regional haze, while other sources (e.g., fossil fuel burning) contribute the remainder.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director, Office of Science. Office of Biological and Environmental Research; National Aeronautics and Space Administration (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 825310
- Report Number(s):
- LBNL-50880; R&D Project: 574701; TRN: US200421%%200
- Journal Information:
- Journal of Geophysical Research - Atmospheres, Vol. 108, Issue D13; Other Information: Journal Publication Date: 02/20/2003; PBD: 17 Jun 2002; ISSN 0747-7309
- Country of Publication:
- United States
- Language:
- English
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