Showing papers by "Paul J. Crutzen published in 1984"
TL;DR: In this article, the authors present simulations with a two-dimensional "Staubsauger" or "vacuum cleaner" model that combines a photochemical model with a description of vertical transport of trace species by convective clouds within larger synoptic circulations.
Abstract: Reactive surface emissions of reduced sulfur gases can produce SO2 in the middle and upper troposphere at the levels of 80±30 pptv measured high over the remote oceans. We present simulations with a two-dimensional “Staubsauger” or “vacuum cleaner” model that combines a photochemical model with a description of vertical transport of trace species by convective clouds within larger synoptic circulations. Emissions of 20–60 Tg (S)/yr of (CH3)2S, H2S, or CS2, may produce the observed SO2. Roughly equal production rates of SO2 and methane sulfonic acid may be expected. The amount and exact vertical distribution of the SO2 produced remain uncertain: the greatest chemical uncertainties are the reaction yield of SO2 expectable under clean tropospheric conditions and also the liquid-phase removal of SO2, and the oxidation rate. The amount of upper tropospheric SO2 produced depends substantially on the proximity of strong reduced S sources to regions of active convection. However, the character of the solutions we present is invariably distinctly different from those obtained with one- or two-dimensional models employing the eddy-diffusion hypothesis. The results of the model point beyond its original conception, and stress the likely importance of the rainy tropical jungles and mid-latitude industrial regions, since both regions have large sulfur emissions arid frequently active cumulonimbus convection. This process, however, should contribute mainly to upper-tropospheric SO2. Other chemical implications are that tropospheric OH may depend critically on HOOH levels as well as the hydrocarbon and nitrogen oxide cycles. Cloud transport may play an important role in these cycles. The hydroxyl radical concentration depends as much on assumptions regarding HOOH reaction and transport as it does on NO levels.
321 citations
TL;DR: In this article, an analysis of the amounts of various types of fuels which could burn in a nuclear war indicates that more than 1014 g of black smoke could be produced by fires started by the nuclear explosions, which could temporarily cause extreme darkness in large areas in midlatitudes and reduce crop growth and biospheric productivity.
Abstract: During a large nuclear war, the atmosphere would be loaded with huge quantities of pollutants, which are produced by fires in urban and industrial centers, cultivated lands, forests and grasslands. Especially detrimental are the effects of light absorbing airborne particles. An analysis of the amounts of the various types of fuels which could burn in a nuclear war indicates that more than 1014 g of black smoke could be produced by fires started by the nuclear explosions. Due to this, the penetration of sunlight to the earth's surface would be reduced greatly over extended areas of the northern hemisphere, maybe even globally. This could temporarily cause extreme darkness in large areas in midlatitudes and reduce crop growth and biospheric productivity. This situation would last for several weeks and cause very anomalous meteorological conditions. Much solar radiation would be absorbed in the atmosphere instead of at the earth's surface. The land areas and lower atmosphere would, therefore, cool and the overlying atmosphere warm, creating strong vertical thermal stability in a highly polluted atmosphere. For extended periods and in large parts of the world, weather conditions would be abnormal. The resulting cold, probably freezing, temperatures at the ground would interfere severely with crop production during the growing season and cause extreme conditions for large sections of the biosphere. The combination of lack of sunlight, frost and other adverse meteorological conditions would add enormously to the already huge problems of the survivors.
88 citations