Seasonal and interannual variability on the chemical composition of the Svalbard surface snowpack

The Svalbard Archipelago, highly sensitive to rapid environmental changes, offers an ideal physical laboratory to investigate how environmental drivers can shape the seasonal chemical composition of snow in a warming climate. From 2018 to 2021, sampling campaigns at the Gruvebadet Snow Research Site in Ny-& Aring;lesund, in the North-West of the Svalbard Archipelago, captured the interannual variability in ionic and elemental impurities within surface snow, reflecting seasonal differences in atmospheric and oceanic conditions. Notably, warmer conditions prevailed in 2018-2019 and 2020-2021, contrasting with the relatively colder season of 2019-2020. Our findings suggest that impurity concentrations in the 2019-2020 colder season are impacted by enhanced sea spray aerosol production, likely driven by a larger extent of sea ice, and drier, windy conditions. This phenomenon was particularly evident in March 2020, when extensive sea ice was present in Kongsfjorden and around Spitsbergen due to an exceptionally strong, cold stratospheric polar vortex and unusual Arctic Oscillation (AO) index positive phase. This study provides a detailed characterization of how snow chemistry in this area responds to major environmental conditions, with particular attention to sea-ice extent, atmospheric circulation, synoptic conditions, and Arctic climate variability.