Sulfur atmospheric burden

Husain, L V. A. Dutkiewicz, and M. Das, Evidence for Decrease in Atmospheric Sulfur Burden in the Eastern United States Caused by Reduction in S02 Emissions, Geophys. Res. Lett., 25, 967-970 (1998). 

The sixth, seventh, and eighth sections of this volume deal with the atmospheric cycling of biogenic sulfur compounds. This aspect of the sulfur cycle has received a great deal of attention in recent years because of its obvious relationship to the add rain problem and the discovery that natural marine sources constitute a major portion of the total global atmospheric sulfur burden. The chapters in these sections focus on three aspects of this cycle field measurements and techniques used to establish the distributions and fluxes, experimental studies of reaction mechanisms and rates, and numerical simulations of the atmospheric sulfur cycle. Two chapters address the chemical processes involving cloud... 

Fig. 13-5 The sulfur cycle in the remote marine boundary layer. Within the 2500 m boundary layer, burden units are ng S/m and flux units are ng S/m h. Fluxes within the atmospheric layer are calculated from the burden and the residence time. Dots indicate that calculations based on independent measurements are being compared. The measured wet deposition of nss-SO " (not shown) is 13 7 //g S/m /h Inputs and outputs roughly balance, suggesting that a consistent model of the remote marine sulfur cycle within the planetary boundary layer can be constructed based on biogenic DMS inputs alone. Data (1) Andreae (1986) (2) Galloway (1985) (3) Saltzman et al. (1983) (4) sulfate aerosol lifetime calculated earlier in this chapter based on marine rainwater pH the same lifetime is applied to MSA aerosol. Modified from Crutzen et al. (1983) with the permission of Kluwer Academic Publishers.

Global atmospheric sulfur burden over the oceans and continents according to Friend (1973) and E. Meszaros (1978)... 

We have to emphasize here that the majority of the sulfate-sulfur in the tropospheric reservoir in not sea salt. Friend (1973) estimated that the atmospheric sea-salt burden is around 0.1 x 106 t. By subtracting this value from the sulfate-sulfur loading given in Fig. 19 and considering only the strength of chemical sources (62 x 106 t yr 1), a residence time of more than 4 days is obtained for the excess sulfate. 

The choice between cap-and-trade systems and pollution taxes rests at least in part on the pollutant in question. For pollutants like sulfur dioxide, CFCs, or carbon dioxide that mix equally in the atmosphere and that pose few or no local health effects, cap-and-trade works well because we are unconcerned about where emissions take place. On the other hand, if we are concerned that limiting emissions might impose too big a burden on the economy, the pollution tax approach is best because sources know that they will never have to pay more for a ton of pollution discharged than the tax. Effluent charges also raise revenue—not a trivial issue in many places, including developing countries. 

The State implementation plans promulgated in the U.S. in the early 1970s to meet the NAAQS for SO2 resulted in reductions in the allowable sulfur contents of fuels used, especially for smaller, distributed sources. Such limitations resulted in reductions in ambient levels of all sulfur compounds near the sources, i.e., in cities. An alternative strategy to meet the NAAQS for SO2 for sources that could not easily switch fuels involved increasing stack heights, which greatly reduces the local surface air concentrations but does not reduce the total atmospheric sulfur burden. As a result, over the past 20 years, U.S. sulfate air concentrations have not improved as much as urban SO2 concentrations and may have actually increased in some remote areas. U.S. total emissions peaked about 1970 and remain at about the levels of the late 1960s. 

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