Atmospheric lead transport characteristics

Our own approach is somewhat different and emphasizes spectra produced by thermal emission from planetary atmospheres, especially as observed from space platforms. In order to demonstrate the connection between the thermal radiation giving rise to these spectra and the physical state of the atmosphere under consideration, it is necessary to examine how the transport of this radiation is effected. Only then is it possible to have a clear understanding of how the structure of an atmosphere leads to its spectral appearance, a topic considered at length in Chapter 4. Once this is accomplished a reversal of the procedure is feasible, and in Chapters 6 through 9 we demonstrate how the observed characteristics of the radiation field imply the underlying physical structure and the state of the interacting atmosphere. 

Acidification pollutants, nutrients and chemicals being transported via the atmosphere to alpine regions originate from both nearby and far away sources. Deposition mainly occurs on the land surface where they can lead to soil and subsequent water acidification. Nutrients and chemicals are partly released from soil and land surfaces to water depending on their chemical nature, and on land and soil characteristics (cf. [7, 10], this volume). 

The environmental processes of transformation, transport, and deposition of lead are prominently influenced by the particle sizes. Size distributions of lead particulates have been studied to determine their relation to numerous evironmental questions [21, 27, 28, 34]. These investigations have determined that the smaller lead particles (less than 0.5 pm in diameter) make up the largest fraction of those exhausted from internal combustion engines, with mean particle size decreasing with increasing speed. There is little modification of the characteristics of the lead particulate size distribution as a result of non-precipitative atmospheric mechanisms. 

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