Historic CH4 Records from Antarctic and Greenland Ice Cores, Antarctic Firn Data, and Archived Air Samples from Cape Grim, Tasmania

• Main Authors: D. M. Etheridge, L. P. Steele, R. J. Francey, R. J. Langenfelds
• Format: Dataset
• Language: unknown
• Published: ESS-DIVE: Deep Insight for Earth Science Data 2002
• Subjects: CH4 measurements; CH4 mixing ratio; atmospheric CH4 reconstructions; TRENDS-OTHER ATMOSPHERIC TRACE GASES; mean air age; mean ice depth; ice age year A.D.; ice sample code; year A.D.; 75 year smoothing spline; Antarctic; The Antarctic; East Antarctica; Greenland; Law Dome; Grim; Antarc*; Antarctica; Greenland ice cores; ice core; Ice Sheet
• Online Access: https://search.dataone.org/view/ess-dive-47b6690fb47c0e7-20180704T210533551

The Antarctic CH4 records presented here are derived from three ice cores obtained at Law Dome, East Antarctica (66°44'S, 112°50'E, 1390 meters above mean sea level). Law Dome has many qualities of an ideal ice core site for the reconstruction of past concentrations of atmospheric gases; these qualities include: negligible melting of the ice sheet surface, low concentrations of impurities, regular stratigraphic layering undisturbed by wind stress at the surface or differential ice flow at depth, and a high snow accumulation rate. Further details on the site, drilling, and cores are provided by Etheridge et al. (1998), Etheridge et al. (1996), Etheridge and Wookey (1989), and Morgan et al. (1997). The two Greenland ice cores are from the Summit region (72°34' N, 37°37' W, 3200 meters above mean sea level). Lower snow accumulation rate there results in lower air-age resolution, and measurements presented here cover only the pre-industrial period (until 1885). More details about these measurements are presented in Etheridge et al. (1998). Additionally, this site contains firn data from Core DE08-2, and archived air samples from Cape Grim, Tasmania, for comparison. For access to the data files, click this link to the CDIAC data transition website: http://cdiac.ess-dive.lbl.gov/trends/atm_meth/lawdome_meth.html