This data compilation is a collaborative effort by the CLIVASH2k (Climate Variability in Antarctica and the Southern Hemisphere over the past 2000 years) working group, part of the PAGES2k network. The database is a compilation of sodium and sulphate records from Antarctic ice cores spanning the past 2000 years, and contains a combination of published records (sourced from public archives), and unpublished data submitted to the CLIVASH2k call. All data are provided as annual averages (Jan-Dec). This database includes the annually resolved section of each original dataset (in the annual_resolution folder) and the coarser than annual sections (in the coarse_resolution folder). Annual averages for the oldest and most recent years were only included if the available data covered more than half of the year. All concentration values are presented in parts per billion (ppb). All flux values are presented in ppb by kilogram per square meter (ppb kg m-2). Data for each species are contained in separate CSV files; Sodium concentration (Na_concentration), Sodium flux (Na_flux), Sulphate concentration (SO4_concentration), Sulphate flux (SO4_flux), Excess Sulphate (xsSO4), Excess Sulphate flux (xsSO4_flux). Each file contains the data for all sites. The Excess Sulphate and Excess Sulphate flux calculations assume that all Na comes from the ocean (according to the standard seawater ion ratio as in [Holland, 1978]). Data were submitted in both the ionic (e.g. SO42-) and elemental forms (S). Elemental S has been converted to sulphate (SO42-) by multiplying by three. A data description publication accompanies this database: Thomas et al., The CLIVASH2k ice core chemistry database: an Antarctic compilation of sodium and sulphate records spanning the past 2000 years. Earth System Science Data. This database was created with the support of the CLIVASH2k project.

Persistent organic pollutant concentrations in artificial sea ice experiments at the Roland von Glasow Air-Sea-Ice Chamber (RvG-ASIC) at the University of East Anglia, UK. Experiments involved investigating chemical contaminant behaviours during sea ice formation and melt in order to assess possible exposure risk to sea ice biota. Funding was provided by: NERC ENVISION Doctoral Training Centre (NE/L002604/1). NERC and the German Federal Ministry of Education and Research (BMBF) funded Changing Arctic Ocean program EISPAC project (NE/R012857/1). British Antarctic Survey Collaboration Voucher. EUROCHAMP-2020 Infrastructure Activity under grant agreement (No 730997).