Water chemistry data from 19644 seasonally ice-covered lakes

This dataset contains water chemistry monitoring data and lake morphometry data from 19644 lakes collected between 1960 and 2022 in Finland, Sweden, Norway, Canada and the United States, as well as ice phenology observations from 1107 lakes in the same regions. Data was sourced from governmental databases and non-profit organizations via data portals and data requests (see Metadata). The dataset contains over 5.3 million standardized and quality-controlled observations of dissolved oxygen, water temperature, total phosphorus, chlorophyll-a, water colour as well as sampling location, sampling date, sampling depth and key lake properties including lake altitude, surface area, mean depth and maximum depth. Ice phenology observations include ice freeze-up and breakup dates. We excluded lakes undergoing physical or chemical treatments against hypoxia, lakes in which experiments have been conducted (e.g. nutrient addition). and reservoirs. The consumer of these data ("Data User" herein) should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is". The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors, original data providers and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. The data user may not create derivatives of this dataset or re-distribute these data to a third party. Note: if you would like to use this data in your own study, you must contact the author ([e-mail]) to ensure compliance with requirements of the contributors to this synthesis dataset,本数据集涵盖1960年至2022年间，采集自芬兰、瑞典、挪威、加拿大及美国共19644个湖泊的水化学监测数据与湖泊形态学（lake morphometry）数据，同时包含上述区域内1107个湖泊的冰物候（ice phenology）观测数据。本数据集的数据通过数据门户与数据申请渠道，从政府数据库及非营利组织获取（详见元数据（Metadata））。 本数据集包含超530万条经过标准化处理与质量管控的观测记录，涵盖溶解氧（dissolved oxygen）、水温（water temperature）、总磷（total phosphorus）、叶绿素a（chlorophyll-a）、水体色度等指标，同时附带采样点位、采样日期、采样深度等采样信息，以及湖泊海拔、表面积、平均水深、最大水深等核心湖泊属性数据。冰物候观测数据包含湖泊封冻与解冻日期。本数据集剔除了接受过针对缺氧（hypoxia）的物理或化学处理、开展过相关实验（如营养盐添加实验）的湖泊，以及水库。 本数据集的使用者，即数据用户（Data User），需注意：若脱离原始研究的上下文使用数据，可能会出现数据误读情况。尽管已通过大量工作确保数据及相关文档的准确性，但无法保证数据集的完全精确。所有数据均按“现状”提供。但数据用户需知晓，数据集会定期更新，数据用户有责任核查数据的最新版本。数据作者、原始数据提供方以及本数据集的托管仓库，不对因使用或误读数据所导致的任何损害承担责任。数据用户不得对本数据集进行衍生创作，亦不得将数据转分享给第三方。 注意：若您计划在自身研究中使用本数据集，需联系作者（[e-mail]），以确保符合本合成数据集贡献者的相关要求。