High-resolution non-sea-salt sulphur and sea-salt sodium data of firn core OH-12 from Plateau Laclavere, northern Antarctic Peninsula

The firn core OH-12 was retrieved from Plateau Laclavere, a small ice cap on the northernmost end of the Antarctic Peninsula at about 1090 m above sea level in January 2016. The core was drilled down to 19.93 m depth. Glacio-chemical parameters (hydrogen peroxide, sulphur, sodium, black carbon) were determined in summer 2017 using a Continuous Flow Analysis (CFA) system as described by Röthlisberger et al. (2000) and McConnell et al. (2002, 2007). Sulphur and sodium concentrations were measured using two Thermo Finnigan Element2 High Resolution-Inductively Coupled Plasma-Mass Spectrometry (HR-ICP-MS) instruments. Values of sea-salt sodium (ssNa) and non-sea-salt sulphur (nssS) were calculated from sodium and sulphur concentrations applying the approach of Röthlisberger et al. (2002) and Sigl et al. (2013) and using relative abundances from Bowen (Bowen, 1979). The core was dated using annual layer counting of hydrogen peroxide measurements. We additionally accounted for precipitation intermittency at the drill site by using precipitation data from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 Reanalysis extracted from the grid point closest to the firn-core drill site. The core covers the period from July 2011 to January 2016. The data has been used for investigating recent climate and environmental changes in the northern Antarctic Peninsula region providing the basis for the retrieval and analysis of a deeper ice core from the same site.