Abstract. Most inhabitants of the Arctic live near the coastline, which includes fjord systems where socio-ecological coupling with coastal communities is dominant. It is therefore critically important that the key aspects of Arctic fjords be measured as well as possible. Much work has been done to monitor temperature and salinity, but in-depth knowledge of the light environment throughout Arctic fjords is lacking. This is particularly problematic knowing the importance of light for benthic ecosystem engineers such as macroalgae, which also play a major role in ecosystem function. Here we document the creation and implementation of a high-resolution (∼50–150 m) gridded dataset for surface photosynthetically available radiation (PAR), diffuse attenuation of PAR through the water column (KPAR), and PAR available at the seafloor (bottom PAR) for seven Arctic fjords distributed throughout Svalbard, Greenland, and Norway during the period 2003–2022. In addition to KPAR and bottom PAR being available at a monthly resolution over this time period, all variables are available as a global average, annual averages, and monthly climatologies, with standard deviations provided for the latter two. Throughout most Arctic fjords, the interannual variability of monthly bottom PAR is too large to determine any long-term trends. However, in some fjords, bottom PAR increases in spring and autumn and decreases in summer. While a full investigation into these causes is beyond the scope of the description of the dataset presented here, it is hypothesized that this shift is due to a decrease in seasonal ice cover (i.e. enhanced surface PAR) in the shoulder seasons and an increase in coastal runoff (i.e. increased turbidity and decreased surface PAR) in summer. A demonstration of the usability of the dataset is given by showing how it can be combined with known PAR requirements of macroalgae to track the change in the potential distribution area for macroalgal habitats within fjords with time. The datasets are available on PANGAEA at https://doi.org/10.1594/PANGAEA.962895 (Gentili et al., 2023a) and https://doi.org/10.1594/PANGAEA.965460 (Gentili et al., 2024). A toolbox for downloading and working with this dataset is available in the form of the FjordLight R package, which is available via CRAN (Gentili et al., 2023b, https://doi.org/10.5281/zenodo.10259129) or may be installed via GitHub: https://face-it-project.github.io/FjordLight (last access: 29 April 2024).

中文翻译：

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北极峡湾的水下光环境


摘要。北极的大多数居民居住在海岸线附近，其中包括与沿海社区的社会生态耦合占主导地位的峡湾系统。因此，尽可能地测量北极峡湾的关键方面至关重要。人们在监测温度和盐度方面做了很多工作，但缺乏对整个北极峡湾光环境的深入了解。了解光对于大型藻类等底栖生态系统工程师的重要性尤其成问题，因为大型藻类在生态系统功能中也发挥着重要作用。在这里，我们记录了高分辨率（∼50–150 m）网格数据集的创建和实现，该数据集用于表面光合有效辐射（PAR）、通过水柱的 PAR 漫反射衰减（KPAR）以及海底可用的 PAR（底部） 2003 年至 2022 年期间分布在斯瓦尔巴群岛、格陵兰岛和挪威的七个北极峡湾的 PAR）。除了该时间段内每月分辨率的 KPAR 和底部 PAR 之外，所有变量均以全球平均值、年平均值和每月气候学形式提供，并为后两者提供了标准差。在大多数北极峡湾，月度底部 PAR 的年际变化太大，无法确定任何长期趋势。然而，在一些峡湾，底部 PAR 在春季和秋季增加，在夏季减少。虽然对这些原因的全面调查超出了此处提供的数据集描述的范围，但假设这种变化是由于平季季节性冰盖减少（即表面有效光合有效辐射增强）和沿海地区冰盖增加造成的。夏季径流（即浑浊度增加和地表有效光合有效辐射降低）。 通过展示如何将数据集与大型藻类的已知 PAR 要求相结合来跟踪峡湾内大型藻类栖息地的潜在分布区域随时间的变化，展示了该数据集的可用性。这些数据集可在 PANGEA 上获取：https://doi.org/10.1594/PANGAEA.962895（Gentili 等人，2023a）和 https://doi.org/10.1594/PANGAEA.965460（Gentili 等人，2024） 。用于下载和使用该数据集的工具箱以 FjordLight R 包的形式提供，该包可通过 CRAN 获得（Gentili 等人，2023b，https://doi.org/10.5281/zenodo.10259129），或者可以通过通过 GitHub 安装：https://face-it-project.github.io/FjordLight（上次访问日期：2024 年 4 月 29 日）。