High-resolution chlorine data of firn core OH-12 from Plateau Laclavere, northern Antarctic Peninsula

Firn core OH-12 was retrieved from Plateau Laclavere, a small ice cap on the northernmost end of the Antarctic Peninsula. It was drilled in January 2016 to a depth of 19.93 m at about 1090 m a.s.l. using a portable solar-powered and electrically operated ice-core drill (Backpack Drill; icedrill.ch AG). Glacio-chemical parameters in OH-12 (calcium, chlorine, strontium, dysprosium, cerium, lanthanum) were determined at the Trace Chemistry Laboratory of the Desert Research Institute (DRI) in Reno, Nevada, USA, in summer 2017 using two Thermo Finnigan Element2 High Resolution-Inductively Coupled Plasma-Mass Spectrometry (HR-ICP-MS) instruments connected to a Continuous Flow Analysis (CFA) system as described by Röthlisberger et al. (2000) and McConnell et al. (2002). 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 sites. OH-12 covers the period from July 2011 to January 2016.