Measurements for snow pits dug across Taylor Valley were obtained for this dataset during November and December of the 2021-2022 field season. Snow patches were specifically sampled early in the year before the streams had started to flow. Snow pits were dug both within stream channels and adjacent to stream channels for 10 streams across Lake Fryxell Basin and Commonwealth Stream in Taylor Valley. Snow depth of each pit was recorded and snow density was measured using a snow cutter of known volume and a spring scale. Snow density and snow depth was then used to calculate snow water equivalent (SWE) of each snow patch sampled.

Snow samples for each pit were also collected using a snow core device. The snow samples were put in a whirlpack bag and transported back to the field laboratory at F6 camp. At F6, samples were melted and filtered for nutrient, cation, and anion analysis. Because not all samples had enough water for all analysis, nutrient analysis was prioritized and anions/cations were not able to be run for every sample. For anions and cations, 50 mls (for each) of the melted snow water was filtered through a Nucleopore (0.4 µm) filter. The filtrate was saved and stored at +4 °C for future analysis. For nutrients, 100 ml of raw melted snow sample was filtered through an ashed GF/C filter. The filtrate was saved and frozen at -20 °C for future analysis.

All analysis was run by the MCM LTER at the Crary Laboratory at McMurdo Station or at the University of Colorado Boulder, in the same way that stream water samples are rum as part of the long-term sample collection for the MCM LTER. Anions and cations were run in the Crary Laboratory at McMurdo Station between 2021-12-03 and 2022-01-14 with a dilution factor of 1. Nutrients (N & SRP) were run at the University of Colorado Boulder on 2022-06-07.