Showing papers by "Paul J. Crutzen published in 1976"
TL;DR: In this article, it is shown that photodissociation of CSO (and possibly CS2) may provide an interesting stratospheric source of SO2 and further conversion of this SO2 to H2SO4 may contribute significantly to the nonvolcanic background sulfate layer in the stratosphere.
Abstract: Photodissociation of CSO (and possibly CS2) may provide an interesting stratospheric source of SO2 and further conversion of this SO2 to H2SO4 may contribute significantly to the non-volcanic background sulfate layer in the stratosphere. Assuming a tropospheric background volume mixing ratio of 2-3 × 10−10, as indicated by some tropospheric measurements, the input of SO2 in the stratosphere coming from the decay of CSO is estimated to be 6 × 106 - 107 molecules cm−2s−1. Little is known about the sources and sinks of CSO. It is, therefore, clear that, as a matter of caution, a possible growth of industrial releases of CSO (and CS2) into the atmosphere, e.g., from coal combustion, should be watched carefully with regard to their influence on the stratospheric aerosol layer and the earth's radiation balance.
586 citations
TL;DR: In this article, it was shown that the Earth's N2O budget is severely limited, and it may not be excluded, a priori, that not only the source but also its sink is affected by man, and therefore it is essential that a well balanced, interdisciplinary research effort now be designed to increase our knowledge of all aspects of the earth's nutrient cycles.
Abstract: Our understanding of the marine and terrestrial nitrogen budgets is severely limited. For instance, atmospheric data indicate a residence time of N2O in the atmosphere of about 10 years and consequently sources and sinks of atmospheric N2O of the order of 130×106 ton N/year. Such large sources and especially sinks for atmospheric N2O have not been satisfactorily identified and it may not be excluded, a priori, that not only the N2O source, but also its sink is affected by man. The limited knowledge about the earth's N2O budget so far obtained is in favor of the view that there is no imminent danger of large ozone reductions following the predicted increase in the input of fixed nitrogen in the soil by the year 2000. However, it seems likely that, with unchanged agricultural practices, there will develop serious long term problems, certainly in a world of exponential growth, and, for best action, it is essential that a well balanced, interdisciplinary research effort now be designed to increase our knowledge of all aspects of the earth's nutrient cycles.
106 citations
TL;DR: There is mounting evidence that past extinctions of faunal species have occurred in near-coincidence with reversals in polarity of the geomagnetic field as discussed by the authors.
Abstract: There is mounting evidence that past extinctions of faunal species have occurred in near coincidence with reversals in polarity of the geomagnetic field. Could the link lie in catastrophic depletions of stratospheric ozone caused by solar-proton irradiation over a reduced geomagnetic field?
74 citations
TL;DR: In this article, it was shown that ionmolecule reactions do not play a significant role in restricting the lifetime of CFCl3 or CF2Cl2 in the atmosphere or in removing the reactive products Cl, HCl, and ClO.
Abstract: The possibility of significant losses of chlorofluoromethanes and their photochemical products in the troposphere or stratosphere has been examined. A number of laboratory measurements have been carried out involving possible ambient positive and negative ions and CFCL3, CF2Cl2 and HCl. No reactions between ions expected to have significant concentrations and these species have been observed. It appears that the reactions which might have been important are in fact endothermic. This is a result of normal atmospheric chemistry leading to very stable ions on a very short time scale. We conclude that ionmolecule reactions do not play a significant role in restricting the lifetime of CFCl3 or CF2Cl2 in the atmosphere or in removing the reactive products Cl, HCl, and ClO.
53 citations