Königshafen Submarine Groundwater Discharge Network (KiSNet)

海底地下水排放（SGD）作为陆地和海洋之间水和化学成分的通道是一个相当年轻的话题，但它对全球范围内营养循环的影响可能与河流的输入一样重要。然而，尽管重要，迄今报告的SGD通量数据包含很大的不确定性，要么是因为它们是从局部点测量放大到区域尺度，要么是因为它们是从区域甚至全球物质通量的建模/预算中得出的。这些不确定性源于三个方面：1)在不知道每种方法和每种通量结果之间的关系的情况下，检索通量的方法不同。反过来，跨方法的SGD通量比较很少是可能的。2) SGD通量测量是在短时间内进行的点测量。反过来，现有的时空SGD变异性被忽略，导致通常不具有代表性的通量测量。3)尽管存在其他学科的进一步方法，但SGD调查大多是学科（海洋或陆地）。如果调查是跨学科的，就会减少与遗传方法有关的不确定性，这在全球变化的背景下是完全需要的，特别是影响到沿海地区。拟议的网络旨在为SGD专家的跨学科小组提供所需的平台，以启动和加强跨学科的合作关系。它还寻求利用跨学科的基础事实来改进个别方法，从而在陆地和海洋学科的方法之间进行相互比较。最后，该网络将创建一个跨学科方法目录，概述定性和定量SGD调查的最佳组合，这将是未来SGD研究的基础。为了达到这些目标，将围绕定期会议建立网络，其中四次是面对面会议。第一次会议和最后一次会议分别是启动会议和结果会议。第二次和第三次会议是为了在叙尔特岛Königshafen潮间带湾进行比较实验。在实验过程中，SGD专家跨学科网络将首次在同一地点和同一时间应用陆地和海洋学科的几种定量和定性方法。因此，这一行动方针将把来自SGD相关的所有海洋和陆地学科的年轻和经验丰富的科学家聚集在一起，但它也将有助于为所有网络成员扩大SGD知识，并将以跨学科的视角面对下一代SGD研究人员。其次，方法间比较实验将创建具有跨学科性质的独特数据集。这些数据集将发表在国际同行评审和开放获取的期刊上，我们计划制作一个详细的、开放获取的SGD方法目录，类似于GEOTRACES CookBook。

Submarine groundwater discharge (SGD) as a pathway for water and chemical constituents between land and ocean is a rather young topic, but its influence on nutrient cycles on a global scale, is likely to be as significant as the input from rivers. Yet, despite the importance, so far reported SGD flux data contain large uncertainties, either because they were up-scaled from local point measurements to regional scales or because they were derived from modelling/ budgeting of regional or even global matter fluxes. These uncertainties stem from three aspects: 1) methods to retrieve fluxes differ without knowing how each method and flux results relate to each. In turn, an SGD flux comparison across methods is rarely possible. 2) SGD flux measurements are point measurements conducted over short periods of time. In turn, existing spatiotemporal SGD variability is neglected resulting in not generally representative flux measurement, 3) SGD investigations are mostly disciplinary (either marine or terrestrial) although further methods from other disciplines exist. If investigations are interdisciplinary, inherited method-related uncertainties would be reduced which is utterly needed against the background of global change, which particularly affects coastal regions. The proposed network aims to provide the needed platform for an interdisciplinary group of SGD experts to initiate and intensify collaborative ties across disciplines. It also seeks for an improvement of individual methodologies using an interdisciplinary groundtruthing and thus intercomparison between methods of terrestrial and marine disciplines. Finally, the network will create an interdisciplinary method catalogue which outlines optimal combinations for qualitative an quantitative SGD investigations that will be the basis for future SGD research.To reach these aims, the network will be established around regular meetings of which four are face-to-face meetings. The first and last meetings are a kick-off and result meeting respectively. The second and third meeting serve for an intercomparison experiment at the intertidal bay of Königshafen, Sylt. During the experiment the interdisciplinary network of SGD experts will apply several quantitative and qualitative methods from the terrestrial and marine disciplines at the same site and at the same time for the first time. As a result, this course of action will bring together young and experienced scientists from all SGD-relevant marine and terrestrial disciplines, but it will also help to broaden SGD knowledge for all network members, and it will confront the next generation of SGD researchers with an interdisciplinary view of SGD. Second, the method intercomparison experiment will create data sets that are unique in their interdisciplinary nature. The datasets will be published in international peer-reviewed and open-access journals and we plan to produce a detailed, open-access SGD method catalogue analogous to the GEOTRACES CookBook.