Stroebe Maximilian, Scheringer Martin, Hungerbühler Konrad
Institute for Chemical and Bioengineering, ETH Hönggerberg, Swiss Federal Institute of Technology Zürich, CH-8093 Zürich, Switzerland.
Sci Total Environ. 2006 Aug 31;367(2-3):888-98. doi: 10.1016/j.scitotenv.2005.12.023. Epub 2006 Feb 20.
Junge's variability-lifetime relationship describes the relation between the tropospheric residence time of a volatile trace gas and the coefficient of variation of the tropospheric mixing ratio at a remote location. However, no unique or universal quantification of this relationship exists. It can only be derived on a case-by-case basis for consistent data sets on substances with similar source and sink patterns. Using a multi-media model of the long-range transport of organic compounds, we determine variability-lifetime relationships for volatile substances. Next, we demonstrate how the variability-lifetime relationship can be obtained for semi-volatile organic compounds (SOCs) with the model and we investigate typical deviations from the Junge relationship for volatile compounds that are caused by the multi-media partitioning of SOCs. One cause of deviation from this relationship is substances undergoing significant transport in water so that their distribution in air is noticeably influenced by their distribution in water. The other, wider, deviation is caused by substances with a strong tendency for deposition and re-volatilization. Finally, we address the comparison of the model results with field data. Preliminary analyses of long-term monitoring data for polychlorinated biphenyls at remote sites have shown that the identification of Junge relationships in field data is not straightforward. We discuss possible strategies for the derivation of Junge relationships from field data on SOCs.
容格的变率-寿命关系描述了挥发性痕量气体在对流层中的停留时间与偏远地区对流层混合比的变异系数之间的关系。然而，这种关系并没有唯一或通用的量化方法。它只能针对具有相似源汇模式的物质的一致数据集逐案推导得出。我们使用有机化合物长距离传输的多介质模型，确定挥发性物质的变率-寿命关系。接下来，我们展示如何使用该模型获得半挥发性有机化合物（SOCs）的变率-寿命关系，并研究由于SOCs的多介质分配导致的挥发性化合物与容格关系的典型偏差。偏离这种关系的一个原因是物质在水中经历了显著的传输，以至于它们在空气中的分布受到其在水中分布的显著影响。另一个更广泛的偏差是由具有强烈沉积和再挥发倾向的物质引起的。最后，我们讨论了模型结果与实地数据的比较。对偏远地区多氯联苯长期监测数据的初步分析表明，在实地数据中识别容格关系并非易事。我们讨论了从SOCs实地数据推导容格关系的可能策略。
