dissolved greenhouse gases in water tracks

Water samples were collected in triplicate from flowing, surface water of six water tracks draining the Kuparuk River basin, Alaska. Samples were collected without headspace and kept at collection temperature and under water during transport to the laboratory. 40 mL water was equilibrated with 20 mL ultra-high purity helium. Resulting gas samples were analyzed on a gas chromatograph equipped with a flame ionization detector (CH4) with methanizer (CO2), and an electron-capture detector (N2O). Certified standards were used for calibration of the instrument. Dissolved concentrations were calculated using temperature-specific Henry's coefficients and % saturation was estimated relative to global average atmospheric concentrations monitored by NOAA at Mauna Loa during the season of sample collection during each year.