Showing papers by "Paul J. Crutzen published in 1983"
TL;DR: In this article, the influence of industrial sources from industry, lightning, the stratosphere, and aircraft on the tropospheric distributions of NOx, HNO3, and O3 was analyzed.
Abstract: This paper presents two-dimensional photochemical model simulations that show the influence of the various NOx sources from industry, lightning, the stratosphere, and aircraft on the tropospheric distributions of NOx, HNO3, and O3. We found that, by far, the best agreement with the global observations is obtained if the industrial sources are included in the calculations. Industrial activities have led to substantial increases of ozone concentrations in the lower troposphere of the northern hemisphere. Emissions of NOx by high-flying aircraft have only a small effect on ozone concentrations in the troposphere. The ability of the model to simulate the global distributions of the long-lived chlorocarbons CFCl3 and CF2Cl2 indicates that the interhemispheric exchange is rather well described. The model confirms an earlier finding by Rowland et al. (1982) that the CF2Cl2 emission rates estimated by the Chemical Manufacturers Association (CMA) may be 35–40% lower for the period 1976 through 1980. The model also supports the earlier finding of Hyson et al. (1980) that CFCl3 is apparently increasing roughly 10% faster than the CMA emission rates can account for during the period 1976 through 1980. Although this disparity could be explained by assuming 10% higher emission rates for CFCl3 during the period, the behavior of the interhemispheric gradient indicates that errors in the determination of the absolute concentrations could also be an explanation. The ability of the model to simultaneously simulate measured distributions of the shorter-lived chlorocarbons CH3CCl3, CH2Cl2, C2HCl3, and C2Cl4 indicates that its average OH concentrations are also about correct. Based on these OH concentrations, the model tropospheric budgets of CO, CH4, and CH3Cl are calculated. The computed losses of CO, CH4, and CH3Cl by reaction with OH are 2.1×1015 g CO yr−1, 3.2×1014 g CH4 yr−1, and 1.9× 012 g CH3Cl yr−1, respectively.
277 citations
TL;DR: A review of the stratospheric budgets of odd oxygen, odd nitrogen, nitrous oxide, methane and carbonyl sulfide is given in this article, where it is shown that photochemical models and available ozone observations cannot be reconciled and that there may be particularly severe problems in the 25-35 km region.
190 citations
TL;DR: In this paper, a two-dimensional photochemical model is used to examine changes to the ozone layer caused by emissions of CFCl3, CF2Cl2, CH3CCl3 and CCl4.
Abstract: A two-dimensional photochemical model is used to examine changes to the ozone layer caused by emissions of CFCl3, CF2Cl2, CH3CCl3 and CCl4. The influence of a possible secular increase in tropospheric methane up to 2 percent per year was found to be small, although it acts to mask decreases in total ozone caused by the chlorocarbons. Increasing NO(x) emissions caused by industralization also tend to mask decreases in total ozone and may have caused total ozone to increase by about 1 percent. The model-calculated ozone decreases are estimated to be about 3 percent by 1980. This estimate is higher than estimates by similar models, although it is noted that CCl4 and CH3CCl3 emissions are included in the model in addition to CFCl3 and CF2Cl2. This is significant because the model indicates that CCl4 has dominated the ozone depletions so far, and knowledge of the historical emission rate of CCl4 to the atmosphere is incomplete. There remain sufficient significant disagreements between theoretical and observed concentrations and variabilities, particularly for odd nitrogen and ClO, to caution against assigning too much confidence in the calculated ozone depletion.
98 citations
TL;DR: In this paper, it was shown that a substantial fraction of the NO column abundance as measured near the stratopause resides in the lower thermosphere where correlations of NO with solar and magnetic activity are well documented.
Abstract: Depletion of solar radiation at discrete wavelengths by nitric oxide has a significant impact on the dissociation rate of this gas in the δ(0, 0) and δ(1, 0) bands. Inclusion of the opacity provided by a typical NO profile reduces the dissociation rate in the upper stratosphere to 50–70% of that predicted when the optical depth calculation omits this contribution. A substantial fraction of the nitric oxide column abundance as measured near the stratopause resides in the lower thermosphere where correlations of NO with solar and magnetic activity are well documented. Variations in the thermospheric NO abundance therefore modulate the radiation field at the precise wavelengths absorbed by this molecule in the mesosphere and upper stratosphere. Predicted changes in the dissociation rate arising from a varying thermospheric opacity exceed 8% throughout the mesosphere and reach 15% between 65 km and 95 km.
20 citations
TL;DR: The proceedings of the Second European Symposium on the Physico-Chemical Behavior of Atmospheric Pollutants, held September 29 to October 1, 1981, in Varese, Italy, are described in this article.
Abstract: This book covers the proceedings of the Second European Symposium on the Physico-Chemical Behavior of Atmospheric Pollutants, held September 29 to October 1, 1981, in Varese, Italy. These symposia are organized about every second year to coordinate research within the European Community and in Austria, Switzerland, Sweden, and Yugoslavia under a joint agreement called COST (Cooperation Scientifique et Technique).
The book consists of 13 articles on the identification and analysis of pollutants, 14 on chemical and photochemical reactions, 12 on aerosols, 12 on pollutant cycles, and 21 on transport and modeling and field experiments and ends with five useful summaries written by the session chairman.
2 citations