Dissolved methane concentration variability along freshwater-sea continuum at Cuxhaven, northern Germany, 2021

The dataset is about temporal variability of dissolved methane along the freshwater-sea continuum in northern Germany. Sensors were installed at fixed stations at in total three sites at different water depths. This dataset is from the station in Cuxhaven (53.8771 N, 8.7048 E) taken at about 2-7m depth (depending on the tide). The data was obtained between 11 April and 28 August 2021 in high frequency measurements (1 min) with a methane sensor from Kongsberg (4H Jena model CONTROS HydroC CH4). Methane concentrations were calculated according to manufacturer's instructions, based on temperature and salinity values from COSYNA Container Cuxhaven. For the quality control of the data a local range of 0.1 – 1000 nmol/L was set, a technical range for the pump power 2 – 8 Watt, a spike and gradient value of 1. Due to heavy biofouling the external pump of the sensor failed, resulting in data gaps. For a more detailed description see the article cited in References.本数据集聚焦德国北部淡水-海洋连续体中溶解甲烷的时间变异性。传感器共安装于三个不同水深的固定站点，本数据集来自库克斯港（北纬53.8771°，东经8.7048°）站点，采样深度约为2-7米（随潮汐变化）。数据采集时段为2021年4月11日至8月28日，采用康士伯（Kongsberg）公司的甲烷传感器（4H Jena型号CONTROS HydroC CH4）开展高频测量（间隔1分钟）。甲烷浓度依据制造商说明计算，计算所需温度与盐度数据来源于库克斯港COSYNA集装箱站。数据质量控制设定如下标准：甲烷浓度本地范围为0.1–1000纳摩尔/升，泵功率技术范围为2–8瓦，尖峰及梯度阈值为1。由于严重生物污损，传感器外部泵失效，造成数据缺失。更详细描述请参见参考文献中引用的文章。