Sulfate climate impact

A60. Andreae, M.O. Cofer El, W.R. Crutzen, P.J. Hobbs, P.V. Hollander, J. M. Kuhlbusch, T. Novakov, R. Penner, J.E., 1995 Climate Impacts of Carbonaceous and Other Non-sulfate Aerosols A Proposed Study , Lawrence Berkely Laboratory Document—PUB-5411. 

Atmospheric aerosols have a direct impact on earth s radiation balance, fog formation and cloud physics, and visibility degradation as well as human health effect[l]. Both natural and anthropogenic sources contribute to the formation of ambient aerosol, which are composed mostly of sulfates, nitrates and ammoniums in either pure or mixed forms[2]. These inorganic salt aerosols are hygroscopic by nature and exhibit the properties of deliquescence and efflorescence in humid air. That is, relative humidity(RH) history and chemical composition determine whether atmospheric aerosols are liquid or solid. Aerosol physical state affects climate and environmental phenomena such as radiative transfer, visibility, and heterogeneous chemistry. Here we present a mathematical model that considers the relative humidity history and chemical composition dependence of deliquescence and efflorescence for describing the dynamic and transport behavior of ambient aerosols[3]. 

There are, however, several important niche applications for CAC. Most notably, CACs are used as linings to sewers and mine tunnels. Calcium aluminate cements are resistant to chemical attack from sulfate-producing bacteria that thrive in sewer systems (especially in warmer climates), and sprayed concrete linings to sewers have been shown to resist degradation for periods up to 30 years. The high impact and abrasion resistance of CAC also makes it suitable as a lining material for ore tunnels in mines and because CAC sets rapidly, it can be sprayed onto tunnel walls (as shotcrete ) and even used as a tunnel lining. 

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-... 

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