DOI: 10.5285/9e0ed16e-f2ab-4372-8df3-fde7e388c9a7
title: CLIVASH2k Antarctic ice core chemistry database

description: 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cores spanning the past 2000 years, and contains a combination of published records (sourced from public archives), and unpublished data submitted to the CLIVASH2k call.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.
description: Datasets presented in this database were gathered as part of a collaborative process which included assembling the database (including quality control and validation) and outlining the structure and contents of the database (including data selection criteria, metadata, and chronological information). The target time-period for this database was the last 2000 years. Records of any length could be submitted within this time-period. This includes snow-pits and firn cores, spanning just a few seasons to years. Data were requested at the highest resolution available and converted to annual averages based on the original age-scale provided by the data contributors. All data were converted to ppb (concentration) and ppb kg m-2 (flux). 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.
description: Ionic Sodium (Na+) and sulphate (SO42-) are typically measured by ion chromatography (IC). Elemental sodium (Na) and sulphur (S) are generally measured by inductively coupled plasma mass spectrometry (ICP-MS).
description: -999.99, "NaN" and "zero" values were removed from the original datasets before calculating annual and coarser than annual averages. Annual averages for the oldest and most recent years were only included if the available data covered more than half of the year. Any missing numerical values are then represented as -999.99. In the metadata table that describes the site information and references for the original contributing datasets, missing text values (e.g. dates) are represented as "N/A". The oldest and most recent years reported in the metadata table are based on the longest timespan among all species for each dataset. Flux records from some sites cover a shorter timespan due to shorter accumulation datasets.