Biomass Burning in the Tropics

Certainly, photochemical air pollution is not merely a local problem. Indeed, spread of anthropogenic smog plumes away from urban centers results in regional scale oxidant problems, such as found in the NE United States and many southern States. Ozone production has also been connected with biomass burning in the tropics (79,80,81). Transport of large-scale tropospheric ozone plumes over large distances has been documented from satellite measurements of total atmospheric ozone (82,83,84), originally taken to study stratospheric ozone depletion. 

Crutzen, P. J. and Andreae, M. O. (1990). Biomass burning in the Tropics impact on atmospheric chemistry and biogeochemical cycles. Science 250, 1669-1678. 

Crutzen, P. J and M. O. Andreae, Biomass Burning in the Tropics Impact on Atmospheric Chemistry and Biogeochemical Cycles, Science, 250, 1669-1678 (1990). 

During biomass and fuel burning, a complex mixture of ill-characterized volatile organic matter are released into the atmosphere (Andreae and Merlet, 2001). It contributes to the formation of aerosols and fine particles of sizes up to 100 pm. After an estimated lifetime of 7.9 days (Cook and Wilson, 1996), they are either degraded or are removed from the atmosphere by precipitation. However, they can be transported a considerable distance. For example, boreal forest fires contribute substantially to atmospheric BC in the Arctic (Cook and Wilson, 1996), and Antarctica receives BC from biomass burning in the tropics (Wolff and Cachier, 1998). On a global scale the amount of atmospheric emission is estimated with 5-6Tg BC yr 1,... 

Crutzen PJ, Andreae MO. Biomass burning in the tropics impact on atmospheric chemistry and biochemical cycles. Science 1990 250 1669-1678. 

Observations of biomass burning in the tropics are needed which will enable us to assess far more reliably the role of biomass burning in biogeochemical cycles and in atmospheric chemistry. This research is especially important in view of the increasing use of forest resources in the developing countries. 

Biomass Burning in the Tropics Impact on Atmospheric Chemistry and Biogeochemical Cycles... 

Table 7.1 summarizes the quantitative estimates of biomass burning in the tropics. We estimate that a total of 2700-6800 Tg of C are annually exposed to fires, of which 1800-4700 Tg of C are biuned. The average chemical composition of dry plant biomass corresponds closely to the formula CH2O. The nutrient element content varies with seasonal growth conditions on a mass basis it is relatively low about 0.3-3.8 % N, 0.1-B.9 % S, 0.01-0.3 % P, and 0.5-3.4 % K [25]. Consequently, although the emissions from biomass combustion are dominated by CO2, many products of incomplete combustion that play important roles in atmospheric chemistry and climate are emitted as well, for example, CO, H2, CH4, other hydrocarbons, aldehydes, ketones, alcohols, and organic acids, and compounds... 

In 1979-1980 Crutzen and co-workers drew attention to the great importance of the tropics in atmospheric chemistry. In particular, some measurement campaigns in Brazil clearly showed that biomass burning in the tropics was a major source of air pollutants, on a par with, or larger than, industrial pollution in the developed world. 

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