Characterization of atmospheric methane release in the outer Mackenzie River delta from biogenic and thermogenic sources. Data used in Table 1.

A .pdf file containing geolocated atmospheric CH₄ and CO₂ mixing ratios for the Mackenzie-Beaufort Delta region of the Northwest Territories, Canada. CH₄ and CO₂ values are in parts per million by volume (ppmv). All sample air was drawn from approximately 1 m above ground level. Gas mixing ratios were standardized to Ameriflux FB04306 breathing grade air (benchmarked to 0.5 ppb). Measurements at sites Pingo 3 and Wetland 1 were obtained by using a portable Li-Cor LI-7810 gas analyser in the field. The Li-Cor LI-7810 gas analyser has an accuracy of 0.25 ppb. Measurements at sites Pingo 1, Pingo 2, Wetland 2, Wetland 3, and Site 9 were collected by filling a 30 m coil of 4 mm inside diameter aluminum Synflex tubing while walking at a steady pace across the ground. Coils of tubing were purged with nitrogen and sealed prior to sampling. A constant flow rate of 20 standard cubic centimetres per minute (SCCM) was maintained by attaching a small pump and a flow controller to the coil of tubing. Air samples were analysed immediately on return from the field site by feeding the sample into a Picarro G2210i analyser at the same rate at which it was filled. The Picarro G2210i analyser is accurate to within 0.001 ppm CH₄, and 1 ppm CO₂.