This data set contains atmospheric mixing ratios of hydrogen peroxide and methylhydroperoxide at 21 sites on the West Antarctic Ice Sheet (WAIS) were obtained from 2000 to 2003 during the US International Trans-Antarctic Scientific Expedition (US ITASE) deployments. Sample location from the WAIS region (76-90ºS / 84-124ºW) were approximately 100-300 km apart and correspond to US ITASE ice core sites. At each site, ambient air from 1 m above the snow surface was sampled between two to five days. Atmospheric hydroperoxides (ROOH) were continuously scrubbed from the sample air with a glass coil scrubber and subsequently quantified using a fluorescence detection method. Data are available via FTP as ASCII text files (.txt).