Seasonal variations in the major chemical species of snow at the South East Dome in Greenland

Abstract

We analyze snow-pit samples collected in May 2015 at the South East Dome (SE Dome) on the Greenland ice sheet. The analysis includes high-resolution records of δD and δ18O, as well as the major ions, CH3SO3−, Cl−, NO3−, SO42−, Na+, NH4+, K+, Ma2+, and Ca2+. We find that the 3.55-m snow pit recorded temperature and aerosol proxies back to summer or autumn of 2014. This indicates a higher accumulation rate than those at other major drilling sites in Greenland. Due to this high accumulation rate, ion concentrations except Na+ are lower than those typical of the central Greenland ice sheet. Concerning seasonal variability, the Na+, Cl−, Ca2+, Mg2+, and NO3− vary similarly to other sites in Greenland, with the Na+ and Cl− peaking in winter to early spring, Ca2+ peaking in spring, Mg2+ peaking in winter to spring, and NO3− towards a peak in summer while showing smaller peaks in winter to spring. The NH4+ increased in spring, and SO42− increased in autumn to winter at SE Dome. On the other hand, the seasonal trend in the Cl−/Na+ ratio differs from those in the inland region. As we did not fully recover one seasonal cycle, some seasonal peaks may have been missed.