South Pole Ice Core Methane Data and Gas Age Time Scale

This data set contains measurements of atmospheric methane in the South Pole Ice core made at both Oregon State University and Penn State University, as well as a gas age time scale for the core. In both laboratories methane was measured using a melt-refreeze technique to liberate extracted air and using a gas chromatograph with flame ionization detection to quantify the methane concentration, by comparison to calibrated air standards. To construct the gas time scale abrupt changes in atmospheric methane during the glacial period and centennial methane variability during the Holocene were used to synchronize the South Pole gas record with analogous data from the West Antarctic Ice Sheet Divide ice core. Stratigraphic matching based on visual optimization was verified using an automated matching algorithm. The South Pole ice core recovers all expected changes in methane based on previous records. In combination with an existing ice age scale (Winski et al., 2019, Clim. Past, 15, 1793–1808) an independent estimate of the gas age-ice age difference is also provided. A full description of the data and gas age scale are provided in a forthcoming paper (Epifanio et al, in review in Climate of the Past, Discussions).