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).