North African savanna fires and atmospheric carbon dioxide
The effect of north African savanna fires on atmospheric CO{sub 2} is investigated using a tracer transport model. The model uses winds from operational numerical weather prediction analyses and provides CO{sub 2} concentrations as a function of space and time. After a spin-up period of several years, biomass-burning sources are added, and model experiments are run for an additional year, utilizing various estimates of CO{sub 2} sources. The various model experiments show that biomass burning in the north African savannas significantly affects CO{sub 2} concentrations in South America. The effect is more pronounced during the period from January through March, when biomass burning in South America is almost nonexistent. During this period, atmospheric CO{sub 2} concentrations in parts of South America typically may increase by 0.5 to 0.75 ppm at 970 mbar, the average pressure of the lowest model layer. These figures are above the probable uncertainty level, as model runs with biomass-burning sources estimated from independent studies using distinct data sets and techniques indicate. From May through September, when severe biomass burning occurs in South America, the effect of north African savanna fires over South America has become generally small at 970 mbar, but north of the equator it may be of the same magnitude or larger than the effect of South American fires. The CO{sub 2} concentration increase in the extreme northern and southern portions of South America, however, is mostly due to southern African fires, whose effect may be 2-3 times larger than the effect of South American fires at 970 mbar. Even in the central part of the continent, where local biomass-burning emissions are maximum, southern African fires contribute to at least 15% of the CO{sub 2} concentration increase at 970 mbar. 20 refs., 15 figs., 1 tab.
- OSTI ID:
- 136243
- Journal Information:
- Journal of Geophysical Research, Vol. 99, Issue D4; Other Information: PBD: 20 Apr 1994
- Country of Publication:
- United States
- Language:
- English
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