Surface snow sampling locations across the Arctic Ocean. A) Sampling locations during April and May 2013 (red markers) overlaid on a sea ice map from 17 April 2013. Locations where snow was sampled at multiple depths are highlighted in green. B) Sampling locations from February and April of 2014 (red markers) overlaid on a sea ice map from 14 February 2014. The sea ice maps are derived from Oceansat-2 satellite scatterometry, unavailable over the North Pole. On these maps, white represents multiyear ice (MYI) regions, light blue represents first year ice (FYI) regions, and cyan represents a combination of MYI and FYI regions. The approximate sampling locations from the Krnavek et al. (2012) study are indicated with a yellow star. DOI: https://doi.org/10.1525/elementa.352.f1