Nitrate stable isotopes and major ions in snow and ice samples from four Svalbard sites

Abstract

Increasing reactive nitrogen (N r ) deposition in the Arctic may adversely impact N-limited ecosystems. To investigate atmospheric transport of N r to Svalbard, Norwegian Arctic, snow and firn samples were collected from glaciers and analysed to define spatial and temporal variations (1–10 years) in major ion concentrations and the stable isotope composition ( δ 15 N and δ 18 O) of nitrate ( ) across the archipelago. The and averaged −4‰ and 67‰ in seasonal snow (2010–11) and −9‰ and 74‰ in firn accumulated over the decade 2001–2011. East–west zonal gradients were observed across the archipelago for some major ions (non-sea salt sulphate and magnesium) and also for and in snow, which suggests a different origin for air masses arriving in different sectors of Svalbard. We propose that snowfall associated with long-distance air mass transport over the Arctic Ocean inherits relatively low due to in-transport N isotope fractionation. In contrast, faster air mass transport from the north-west Atlantic or northern Europe results in snowfall with higher because in-transport fractionation of N is then time-limited. To access the supplementary material for this article, please see supplementary files in the column to the right (under Article Tools). Keywords: Nitrate; isotopes; ice cores; Svalbard; pollutants. ( Published: 13 April 2015) Citation: Polar Research 2015, 34 , 23246, http://dx.doi.org/10.3402/polar.v34.23246