pete-d-akers/pituffik_surface_water_iso: Pituffik 2018–2019 surface water stable isotope data and analyses

Release v1.2. This version contains the complete data and R code to analyze the stable isotopic composition of surface waters collected in 2018 and 2019 from Pituffik, Greenland. Changes in v1.2 include an update to the R code file to add new plots and isotopic analyses, including inferred source water modeling and evaporation/inflow ratios, and new csv data files to support the updated R code.