NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Seasonal Variation and Ecosystem Dependence of Emission Factors for Selected Trace Gases and PM2.5 for Southern African Savanna FiresIn this paper we present the first early dry season (early June-early August) emission factor measurements for carbon dioxide (CO2), carbon monoxide (CO), methane (Ca), nonmethane hydrocarbons (NMHC), and particulates with a diameter less than 2.5 microns (pM2.5) for southern African grassland and woodland fires. Seasonal emission factors for grassland fires correlate linearly with the proportion of green grass, used as a surrogate for the fuel moisture content, and are higher for products of incomplete combustion in the early part of the dry season compared with later in the dry season. Models of emission factors for NMHC and PM(sub 2.5) versus modified combustion efficiency (MCE) are statistically different in grassland compared with woodland ecosystems. We compare predictions based on the integration of emissions factors from this study, from the southern African Fire-Atmosphere Research Initiative 1992 (SAFARI-92), and from SAFARI-2000 with those based on the smaller set of ecosystem-specific emission factors to estimate the effects of using regional-average rather than ecosystem-specific emission factors. We also test the validity of using the SAFARI-92 models for emission factors versus MCE to predict the early dry season emission factors measured in this study. The comparison indicates that the largest discrepancies occur at the low end (0.907) and high end (0.972) of MCE values measured in this study. Finally, we combine our models of MCE versus proportion of green grass for grassland fires with emission factors versus MCE for selected oxygenated volatile organic compounds measured in the SAFARI-2000 campaign to derive the first seasonal emission factors for these compounds. The results of this study demonstrate that seasonal variations in savanna fire emissions are important and should be considered in modeling emissions at regional to continental scales.
Document ID
20050179435
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Korontzi, S. (Maryland Univ. College Park, MD, United States)
Ward, D. E. (Forest Service Missoula, MT, United States)
Susott, R. A. (Forest Service Missoula, MT, United States)
Yokelson, R. J. (Montana Univ. Missoula, MT, United States)
Justice, C. O. (Maryland Univ. College Park, MD, United States)
Hobbs, P. V. (Washington Univ. Seattle, WA, United States)
Smithwick, E. A. H. (Wisconsin Univ. Madison, WI, United States)
Hao, W. M. (Forest Service Missoula, MT, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2003
Publication Information
Publication: Journal of Geophysical Research
Volume: 108
Issue: D24
ISSN: 0148-0227
Subject Category
Geophysics
Funding Number(s)
CONTRACT_GRANT: NAG5-9022
Distribution Limits
Public
Copyright
Other