Sub-annually resolved ice core chemistry data from various sites on the Antarctic Ice Sheet were obtained from 1999 to 2008 during the US International Trans-Antarctic Scientific Expedition (US ITASE) deployments. Researchers conducted experiments approximately every 100-300 km looking for clues representing climatic conditions over the past 200-1000+ years. Ice cores, obtained for the ... glaciochemical component of the US ITASE research, were analyzed for soluble major ion content and in some cases trace elements. At each site, a ~3-inch diameter ice core was drilled to depths as great as 120 m. Surface snow samples were collected every ~10-40 km. High-resolution chemical analysis (up to ~75 measurements per meter) was used to define each core-chemistry year based on peaks in Na+, Ca2+, Mg2+, K+, NH4+, Cl-, NO3-, SO42-, CH3SO3- (methylsulfonate), and in some cases trace elements. Extreme events such as volcanic eruptions provide absolute age horizons within each core that are easily identified in chemical profiles. Our chemical analysis is also useful for quantifying anthropogenic impact, biogeochemical cycling, and for reconstructing past atmospheric circulation patterns.