Dissolved CO2, CH4, and ions in groundwater from five sites in the NEON network (CARI, COMO, KING, MART, WALK), U.S., 2021-2024.

This package contains groundwater chemistry measurements collected from groundwater wells between June 2021 – May 2024 at five sites in the U.S. National Ecological Observatory Network (NEON): CARI- Caribou Creek, AK; COMO- Como Creek, CO; KING- Kings Creek, KS; MART- Martha Creek, WA; and WALK- Walker Branch, TN. The dataset includes concentrations of dissolved gases (CO2 and CH4), ions (F, Cl, NO2, Br, NO3, PO4, SO4, Na, NH4, K, Mg, Ca), silica (Si), and nutrients measured by colorimetric methods (NO3, NH4, PO4). When available, we also report measurements of water temperature, specific conductivity (SpC), pH, dissolved O2, and barometric pressure.
Sample collection and analysis was conducted across three labs with additional assistance from the NEON Research Support Services program. Whenever possible, we matched our field sampling methods to NEON’s protocols for groundwater sampling to ensure samples would be comparable to preexisting data from these sites. Any deviations from these protocols are described in the methods.