Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources. Point samples data used in Figure 1 and Figure 4.

A .pdf file containing geolocated atmospheric CH4 and CO2 mixing ratios for the Mackenzie-Beaufort Delta region of the Northwest Territories, Canada. All CH4 and CO2 values are in parts per million by volume (ppmv). Discrete point samples of CH4 and CO2mixing ratios were taken by filling 1 L Tedlar bags with ambient air from approximately 1 m above ground level. CH4 and CO2concentrations and δ13C-CH4 were determined using a Picarro G2210i analyser. All point samples were analysed for at least 5 minutes and the values averaged, which increases the Picarro G2210i analyser accuracy to 0.1 ‰ δ13C-CH4, 0.0001 ppm CH4 and 0.01 ppm CO2. Sample positions were recorded with a Garmin eTrex 10 handheld GPS, which has an accuracy of +/- 3.65 m. Gas mixing ratios were standardized to Ameriflux FB04306 breathing grade air (benchmarked to 0.5 ppb).