Ice covers northern lakes for much of the year and has biological and biogeochemical properties that differ from those in the underlying water. Since 2017, we have studied lake ice and the underlying water in lakes along a latitudinal gradient from the southern coniferous forest in boreal Quebec (48°N, 71°W) where lakes are ice-covered for six months a year with a maximum ice thickness of about 70-100 cm, to Arctic tundra (Victoria Island, 69°N, 105°W) where lakes are ice-covered for 10 months a year with a maximum ice thickness of 2 m, and finally to the High-Arctic polar desert (northern Ellesmere Island and Ward Hunt Island; 83°N, 74°W) where perennially ice-covered lakes are found. A total of 19 lakes were measured for several biogeochemical and limnological variables (dissolved organic matter, CDOM, nutrients, dry weight, chlorophyll, photosynthetic active radiation (PAR) and fatty acids). In addition, we present snow and ice thickness for two lakes over the winter 2017-2018, and PAR, oxygen saturation and conductivity measurements using mooring-based sensors (Ruskin Maestro with underwater quantum sensor Li-192).
