Continuous Antarctic Carbon monoxide (CO) record (spline from 3 ice cores) from 1820 to 1995 CE

Continuous ice core carbon monoxide (CO) mixing ratios are presented for three West Antarctic Cores (Jurassic, Bryan Coast, and Dyer Plateau). Data cover from 1820 CE to 1995 CE. For each core, data are presented integrated at 10-second intervals from an original acquisition rate of 4 Hz. Data were measured continuously utilising Optical Feedback Cavity Enhanced Spectroscopy connected to a continuous ice core melting system at the British Antarctic Survey. A smoothed spline composed of the bottom 5th percentile of each record is also presented. A percentile re-sampling method is required to remove the impact of in situ production. The spline is used to interpret Southern Hemisphere CO variability from the pre-industrial with a particular focus on biomass burning.