Fieldwork was undertaken at the epishelf lake, Blaso, in Northeast Greenland between 19th July and 11th August 2017. CTD casts were made between 27/7/17 and 10/8/17. The CTD operated continuously and was deployed using a hand-spooled winch from a small boat at eight sites across the lake, with the objective of characterising water conditions at both calving fronts and in the three lake basins identified by the CHIRP survey. The CTDs were sampled between 31st July and 10th August 2017 and during this period there was persistent lake ice which prevented CTD measurements close to the eastern calving front. In contrast, most of the lake ice in the western basin had dispersed and melted by early August, allowing access to the western calving margin. Depth temperature and salinity observations are reported as metres (m), degrees centigrade (Deg C) and Practical Salinity Units (PSU). This project was funded by NERC Standard Grant NE/N011228/1

Snow and ice samples were taken from Moutonnee, Ablation and Citadel Bastion lakes on Alexander Island. Isotopic analyses of Oxygen, Carbon and Deuterium were conducted on the samples.

These datasets show how lake water-pressure fluctuated through time over several months in seasonally-frozen catchments in winter. These catchments were in three settings: the lowland Finnish Arctic, an alpine valley and a high cirque in Switzerland. The water-pressure data are accompanied by water temperature and (except for Orajarvi), ground temperature for the same periods. Together, they were used to detect and quantify the water content of snow falling on the lake surfaces. The locations, method of data collection and analysis and the results are described in detail in Pritchard, H. D., Farinotti, D., & Colwell, S. (2021). This work was funded by Natural Environment Research Council (UK) core funding to the British Antarctic Survey, and a fellowship from the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, CH-8903 Birmensdorf, Switzerland.

The long term monitoring of water chemistry in Signy Island lakes is unique in polar limnology, in its duration (30+ years), detail, and range of sites. It details seasonal patterns of snow and ice cover, inorganic nutrient status and chlorophyll-a and includes vertical profiles of various physical chemical parameters. There are detailed data for several study lakes and twice/thrice yearly analyses for all the Signy Island lakes. Temperature and light climate has been studied in certain lakes using automatic data loggers. Micrometeorological monitoring with additional data loggers provided data on solar radiation (PAR, UVR), air temperature, humidity and wind conditions. Data are collected by chemical analysis, use of temperature, pH light probes and observation. The ''grand prix'' was the sampling of 16 lakes in a short period (approx. one week), this was carried out perhaps two or three times a year. Approximately three to five lakes were sampled monthly or fortnightly in more detail, these were representative of the 16 lakes. Comparative studies were also undertaken in the Arctic. The long-term programme was established in 1971, although some observations were made in 1963/1964 and 1969/1970. The programme finished in 2004. As the exact months of the data collection were not provided, and the metadata standard requires a YYYY-MM-DD format, this dataset has been dated as 1st January for start date, and 31st December for stop date.