Black carbon atmospheric aerosols

Averages and standard deviations are presented for the atmospheric concentration (in ng m" ) of the particulate mass, black carbon, and aerosol trace elements in samples collected in Alta Floresta from August 92 to March 95, and in Cuiaba from July 90 to August 95. 

The observational program included getting information about the content and properties of atmospheric aerosol and most substantial optically active MGCs (03, CO, NOx, S02, etc.), but concentrated on aerosol studies to retrieve data on direct and indirect aerosol RF (ARF). The most interesting (and in many respects unexpected) results were connected with detection of a thick aerosol layer in the troposphere (an important feature of aerosol chemical composition consisted in the presence of a considerable black carbon component) and distinct manifestations of the long-range transport of both aerosol and MGCs. 

Today, the anthropogenic emissions of SO, primarily from fossil fuel combustion, largely dominate the sulfur flux into in the atmosphere on the global scale. Climate models have determined the corresponding direct and indirect impacts on radiative forcing, but large uncertainties remain in these estimates. In fact, predictions of future climate need to account not only for the effects of sulfate aerosols, but also for the contributions of mineral dust, black carbon, organic carbon, and sea salt. The current view is that atmospheric particles should be treated as multicomponent, mul-... 

Penner, J. E. (1995) Carbonaceous aerosols influencing atmospheric radiation Black and organic carbon, in Aerosol Forcing of Climate Report of the Dahlem Workshop on Aerosol Forcing of Climate, Berlin 1994, eds., R. J. Charlson and J. Heintzenberg, Wiley, New York, pp. 91-108. 

In addition to atmospheric gases and vapors, aerosols such as sulfate particles, black carbon, and SOA also influence the radiation balance of Earth. The net effect of particles is complex depending on their size, composition, and reflectivity, particles may both absorb and scatter shortwave and longwave radiation. Some particles may make a negative contribution to radiative forcing. For example, particulate emissions from Mt. Pinatubo in 1991 resulted in months of measurably lower surface temperatures. 

Organic compounds are a major constituent of the FPM at all sites. The major sources of OC are combustion and atmospheric reactions involving gaseous VOCs. As is the case with VOCs, there are hundreds of different OC compounds in the atmosphere. A minor but ubiquitous aerosol constituent is elemental carbon. EC is the nonorganic, black constituent of soot. Combustion and pyrolysis are the only processes that produce EC, and diesel engines and wood burning are the most significant sources. 

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