Fig. 2: Black Carbon (BC) concentration around research stations and popular tourism destinations is considerable higher than elsewhere in Antarctica.

a Red dots represent the snow sampling sites. We sampled at 15 sites on the South Shetland Islands (where 16 research stations are located), five sites in the Palmer Archipelago, six sites on or near the coast of the Antarctic Peninsula, and at two deep-field sites on Union Glacier (Ellsworth Mountains); see Table 1 for details. b Boxplots of the BC concentrations in samples from different locations. In each box, the central mark (red stripe) indicates the median, and the edges indicate the 25th and 75th percentiles. The whiskers extend to the maximum and minimum data excluding outliers. c Mean of the absorption Ångström exponent of light-absorbing impurities in samples from different locations. Locations, given in order of latitude, in plots b and c, may combine samples from nearby sites. Measurements in plots b and c were subjected to the statistical significance tests whose results are presented in the Supplementary Information. Plots were generated by using Python’s Matplotlib Library⁵⁸.