Water chemistry data from synoptic sampling surveys in the Upper Kuparuk River, Oksrukuyik Creek, Trevor Creek, and Putuligayuk River, North Slope, Alaska. Summer 2021-2023.

Rapid climate change and intensifying disturbance regimes in the Arctic are altering lateral fluxes of carbon and nutrients from permafrost landscapes to Arctic rivers. However, the seasonal dynamics and landscape characteristics that regulate patterns of solute flux in Arctic watersheds remain poorly understood. To characterize potential drivers of change in solute fluxes across Arctic watersheds, we implemented a spatially extensive synoptic sampling framework within four Arctic watersheds: Upper Kuparuk River, Oksrukuyik Creek, Trevor Creek, and Putuligayuk River. We collected water grab samples at 31-50 nested subcatchments within each watershed up to four times between late May and early September in 2021, 2022, and 2023. We also sampled watershed outlets weekly. We analyzed all samples for a broad suite of biogeochemical constituents including dissolved organic carbon (DOC), organic and inorganic nutrients, dissolved organic matter optical properties, and trace elements and heavy metals, which are provided in this datafile along with sampling date, time, and site coordinates.