Seasonal data for 2 lakes in Kangerlussuaq, Greenland (April 2019-July 2019)

The purpose of this data is to understand how does seasonal dynamics of these periglacial lakes vary between 2 climatic regions from under-ice to open-water periods leveraging high-frequency monitoring and discreet manual sampling of lakewater for analyses of chemistry and biology. This dataset includes water quality measurements (nutrient concentrations, dissolved organic carbon), phytoplankton cell density and biovolume, pigment concentrations, and high-frequency measurements of dissolved oxygen (DO) and photosynthetically active radiation (PAR) collected approx. weekly from two lakes around Kangerlussuaq, Greenland (Lake SS2, Lake SS901) between April and July 2019. These two lakes were selected because they are representative of a suite of lakes located along hydro-climatic gradient in West Greenland (e.g., data from Fowler and Saros, 2019; DOI:10.18739/A2QB9V561). The primary objective of our study was to understand seasonal dynamics of phytoplankton biomass and community structure during the succession from ice-covered to open-water conditions in two oligotrophic, Arctic lakes with different dissolved organic carbon (DOC) concentrations that are representative of a suite of lakes in West Greenland. Specifically, we assessed which factors promote under-ice growth of phytoplankton and trigger shifts in the community structure over time and along vertical gradients within the water column.