Dynamics of reactive and inert gases in soil air and groundwater in the context of thedetermination of noble gas temperatures

过去，地下水中溶解的(稀有)气体是测定年代和重建气候条件的可靠示踪剂。近年来的稀有气体研究表明，有必要更好地了解地下水补给过程中决定气体含量的过程--特别是关于在古气候研究中使用地下水中的稀有气体。因此，在这项研究中，应对各种水文地质和气候条件下地下反应气体过程的重要性进行实证研究，并借助建模。为了得出尽可能笼统的结论，该项目包括总共4个试验场的安装和随后的抽样。要详细了解非饱和土带和饱和土带之间的相互作用，需要收集广泛的物理和化学参数。其中两个试验场将用于长期观测土壤、空气和地下水的气体成分。进一步的试验场首先应该能够调查迄今几乎没有系统研究的地下水脱气现象。最后，第四个试验场应安装在热带气候区域，以调查土壤中降水增加和生物活性增加的影响。首先，系统收集的数据应能够评估其适用性，并在适当的情况下扩展目前讨论的地下水惰性气体浓度模型。这些模型不仅对稀有气体测温方法具有基础性意义，而且对气体示踪剂在地下水测年中的应用也具有重要意义。除了这一应用领域外，这项研究的结果对于更好地了解地下与气体有关的生物地球化学和物理过程具有重要意义。因此，这项研究涉及一个具有实际意义的广泛研究领域，特别是在污染场地和补救措施期间的气体反应和运输方面。

Dissolved (noble) gases in groundwater are established tracers for dating as well as reconstruction of climate conditions in the past. Noble gas studies of recent years have shown that a better understanding of the processes that determine gas contents during groundwater recharge is necessary - especially with regard to the use of noble gases in groundwater in paleoclimate research. Hence, in this study, the importance of reactive gas processes in the subsurface under various hydrogeological and climatic conditions shall be studied empirically as well as with the help of modeling. To derive as general as possible conclusions, the project comprises the installation and subsequent sampling of a total of 4 test sites. A detailed understanding of the interaction between the unsaturated and saturated soil zone requires the collection of a broad range of physical and chemical parameters. Two of the test sites shall serve the long-term observation of the gas composition of soil air and groundwater. A further test site shall in the first place enable the investigation of the so far hardly systematically studied phenomenon of groundwater degassing. Finally, the fourth test site shall be installed in a tropical climate region, in order to investigate the effect of enhanced precipitation and biological activity in the soil.The systematically collected data shall in the first place enable an assessment of the applicability and if appropriate an extension of currently discussed models for the noble gas concentrations in groundwaters. These models are of fundamental significance for the method of noble gas thermometry, but also important for the application of gas tracers for groundwater dating. Beyond this field of application, the results of this study are important for a better understanding of the gas-related biogeochemical and physical processes in the subsurface. Hence the study is related to a wide research field of practical relevance, especially with regard to gas reactions and transport at contaminated sites and during remediation measures.