Climatic and environmental signals recorded in the EGRIP snowpit, Greenland

Abstract

Polar ice sheets conserve atmospheric mineral dust (aerosols) at the time of snowfall, and this material can be used to reconstruct historical climate and environmental conditions. Snowpit samples were obtained from the East Greenland Ice Core Project (EGRIP) site in July 2017. Mineral dust concentrations as well as stable water isotope (δ¹⁸O, δD, and deuterium excess) and major ion (F⁻, Cl⁻, ${\text{NO}}_{2}^{-}$, ${\text{NO}}_{3}^{-}$, ${\text{SO}}_{4}^{2-}$, methanesulfonic acid (MSA), Na⁺, ${\text{NH}}_{\text{4}}^{\text{+}}$, Mg²⁺ and Ca²⁺) concentrations were analyzed in this study. The seasonal δ¹⁸O and δD cycles indicate that the snowpit samples covered the period from winter 2012 to summer 2017. The concentrations of mineral dust and Ca²⁺ showed seasonal deposition events with maxima in the spring layers. The concentrations of MSA exhibited maxima in the summer layers, making them useful indicators for the summer season. Moreover, an anomalous non-sea salt ${\text{SO}}_{4}^{2-}$ (nss ${\text{SO}}_{4}^{2-}$) event was recorded at a depth of 130 − 85 cm that corresponded to the Holuhraun eruption (31 August 2014). In addition, a significant short-term cooling effect was observed. A back-trajectory analysis suggests that a major ash event from Iceland contributed to the Greenland ice sheet (GrIS). These results provide insight for future studies of the EGRIP ice core.