Abstract
To understand the mechanisms of changes in water-stable isotopes and chemical substances in falling snow in northwestern Greenland, we sampled surface snow at the SIGMA-A site of the northwestern Greenland Ice Sheet from 25 May to 6 June 2017, and analyzed water-stable isotopes and chemical substances in the samples. During the observation period, deuterium excess (d-excess) peaked on 30 May and 5 June, corresponding to low concentrations of chemical substances from terrestrial mineral dust and anthropogenic activity and a low Cl−/Na+ ratio, which was close to the ratio in seawater. This suggests that sea salt and air were transported from seawater close to SIGMA-A. Analyses of the backward trajectory and meteorological conditions showed that the air mass leading to the high d-excess snowfall was transported toward SIGMA-A above an open water area in a cold, dry air mass that stayed over Baffin Bay for a relatively long period of time because of cyclonic flow into a depression over 10m above sea level over the bay.
