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As an example of the technique of fingerprint detection of greenhouse climate change, a multivariate signal or fingerprint of the enhanced greenhouse effect is defined using the zonal mean atmospheric temperature change as a function of height and latitude between equilibrium climate model simulations with control and doubled CO2 concentrations. This signal is compared with observed atmospheric temperature variations over the period 1963 to 1988 from radiosonde-based global analyses. There is a significant increase of this greenhouse signal in the observational data over this period.These results must be treated with caution. Upper air data are available for a short period only, possibly too short to be able to resolve any real greenhouse climate change. The greenhouse fingerprint used in this study may not be unique to the enhanced greenhouse effect and may be due to other forcing mechanisms. However, it is shown that the patterns of atmospheric temperature change associated with uniform global increases of sea surface temperature, with El NinoSouthern Oscillation events and with decreases of stratospheric ozone concentrations individually are different from the greenhouse fingerprint used here.  相似文献   
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西秦岭凤太矿集区丝毛岭金矿床地质地球化学特征   总被引:1,自引:0,他引:1  
西秦岭凤太矿集区丝毛岭金矿床位于八卦庙造山型金矿床西侧5km左右,是一个新探明的剪切带型金矿。其成矿作用过程可分为早期石英-绢云母-硫化物阶段、中期多金属-硫化物阶段和晚期碳酸盐阶段。对早、中期的石英流体包裹体测试结果表明,丝毛岭金矿床成矿流体以富CO2、中温、低盐度为特征,总体上属于中温低盐度CO2-H2O体系,流体包裹体类型的多样性是流体不混溶性的产物。从早阶段到主成矿阶段成矿流体的温度、压力和盐度均有降低,硫逸度增高,有利于金的沉淀富集。H、O、S、C同位素研究结果,以及与八卦庙金矿床的对比分析表明,二者的成矿流体具有相似性和同源性,都是以深部来源为主的多源流体。由于丝毛岭金矿床产出的层位高于八卦庙金矿床,其成矿环境相对开放。  相似文献   
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Global climate change is a qualitatively distinct, and very significant, addition to the spectrum of environmental health hazards encountered by humankind. Historically, environmental health concerns have focused on toxicological or microbiological risks to health from local exposures. However, the scale of environmental health hazards is today increasing; indeed, the burgeoning human impact on the environment has begun to alter global biophysical systems (such as the climate system). As a consequence, a range of larger-scale environmental hazards to human population health has emerged. This includes the health risks posed by climate change, stratospheric ozone depletion, loss of biodiversity, stresses on terrestrial and ocean food-producing systems, changes in hydrological systems and the supplies of freshwater, and the global spread of persistent organic pollutants. Appreciation of this scale and type of influence on human health entails an ecological perspective — a perspective that recognises that the foundations of long-term good health in populations reside in the continued stability and functioning of the biosphere's "life-supporting" ecological and physical systems. This revised version was published online in September 2006 with corrections to the Cover Date.  相似文献   
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