Seventy-nine Antarctic ice core snow accumulation records were gathered as part of a community led project coordinated by the PAGES Antarctica 2k working group. Individual ice core records (kg m2 yr-1) were normalised relative to a reference period (1960-1990). The normalised records were separated into seven geographical regions and averaged together to form the regional composites. The seven geographical regions are: East Antarctica; Wilkes Land Coast; Weddell Sea Coast; Antarctic Peninsula; West Antarctic Ice Sheet; Victoria Land; and Dronning Maud Land. Full data description and methods can be found in Thomas et al., 2017. This record also includes the original data, from which the composite records were produced. This dataset represents an updated version of another published dataset. The update was necessary due to erroneous data contained in the files. Please use this corrected dataset in preference to the other one.

Seventy-nine Antarctic ice core snow accumulation records were gathered as part of a community led project coordinated by the PAGES Antarctica 2k working group. Individual ice core records (kg m2 yr-1) were normalised relative to a reference period (1960-1990). The normalised records were separated into seven geographical regions and averaged together to form the regional composites. The seven geographical regions are: East Antarctica; Wilkes Land Coast; Weddell Sea Coast; Antarctic Peninsula; West Antarctic Ice Sheet; Victoria Land; and Dronning Maud Land. Full data description and methods can be found in Thomas et al., 2017. This record also includes the original data, from which the composite records were produced. Due to erroneous data contained in the files, this dataset has been superseded by a corrected version. Please use that corrected dataset in preference to this one to avoid the problem. The DOI for the updated data is: 10.5285/cc1d42de-dfe6-40aa-a1a6-d45cb2fc8293

The file contains Southern Hemisphere winter (September) sea ice concentration (sic) from a simulation performed using the isotope-enabled HadCM3 climate model forced with early last interglacial boundary conditions, centred approximately 128,000 years ago. The resulting sic represents a reduction in winter sea ice area of approximately 54% relative to pre-industrial and is proposed as the best explanation for the Antarctic ice core data from 128,000 years ago. The spatial pattern of sea ice retreat was determined using a large ensemble of model experiments and a pattern search optimization approach to match the last interglacial ice core isotope peak. Further details can be found in the published manuscript (https://doi.org/10.1002/2017GL074594). This work was funded by NERC grants NE/P009271/1, NE/P013279/1, and NE/K004514/1.

The text file (.csv) contains d18O changes simulated at six Greenland deep ice cores (NEEM, NGRIP, GRIP, GISP2, Camp Century and DYE3) from 69 simulations performed using the isotope-enabled HadCM3 climate model forced with mid last interglacial boundary conditions, centred at 125,000 years ago. HadCM3 is used to reproduce the d18O response to 69 modified Last Interglacial (LIG) Greenland Ice Sheet (GIS) morphologies at the ice-core sites. To parameterise the set of 69 GIS morphologies, we undertake a Principal Component Analysis (PCA) approach. The text file also contains the 8PC coefficients for each of the 69 morphologies. The netcdf file (.nc) contains the 8PC shapes and the average shape. To obtain any of the 69 GIS morphologies: (1) store the 8 PC coefficients of a specific GIS morphology and, (2) take a linear combination of the PC shapes (according to those coefficients) and add the average shape. Funding was provided by the following grants: EPSRC-funded Past Earth Network (Grant number EP/M008363/1); NERC funding through grants NE/P009271/1, NE/P013279/1, NE/J004804/1, and Irene Malmierca's PhD studentship.

This dataset provides a 308 year (1702-2009) deuterium isotope record from the Ferrigno 2010 (F10) ice core. The core was drilled on the Bryan Coast in Ellsworth Land, West Antarctica, during the austral summer 2010/11. The record was measured using a Los Gatos Liquid Water Isotope Analyser at 5cm resolution, corresponding to ~14 samples per year, with annual averages calculated for January-December. Funding was provided by the NERC grant NE/J020710/1

This dataset provides a 308 year (1703-2010) annual snow accumulation record from the Ferrigno 2010 (F10) ice core. The 136 m core was drilled on the Bryan Coast in Ellsworth Land, West Antarctica, during the austral summer 2010/11. The record was measured using the summer peak in nonsea-salt (nss) SO4, in approximately January to December. Snow accumulation is converted to meters of water equivalent (weq - m) based on measured density profile and correcting for thinning using the Nye model, assuming vertical strain rate. Samples were measured at 5 cm resolution, corresponding to approximately eight samples per year. Funding was provided by the NERC grant NE/J020710/1.

This dataset provides a 298 year (1712-2010) annual snow accumulation record from the Bryan Coast (BC11) ice core. The 140 m core was drilled on the Bryan Coast in Ellsworth Land, West Antarctica, during the austral summer 2010/11. The record was measured using the summer peak in non sea salt (nss) SO4, in approximately January to December. Snow accumulation is converted to meters of water equivalent (weq - m) based on measured density profile and correcting for thinning using the Nye model, assuming vertical strain rate. Samples were measured at 5 cm resolution, corresponding to approximately eight samples per year. Funding was provided by the NERC grant NE/J020710/1.

We present the age scales for three Antarctic Peninsula (AP) ice cores: Palmer, Rendezvous, and Jurassic. The three age scales are all from intermediate-depth cores, in the 133-141 m depth range. The Palmer age scale covers 390 years, 1621-2011 C.E., and is from one of the oldest AP cores. Rendezvous and Jurassic are from lower elevation high-snow accumulation sites and therefore cover shorter intervals, 1843-2011 C.E. and 1874-2011 C.E., respectively. The Palmer, Rendezvous, and Jurassic cores were all drilled in November-December 2012 using the British Antarctic Survey (BAS) electromechanical dry drill (without drill fluid). Water isotopes and the chemical species used to establish the age scales were measured in the ice core labs at BAS (Cambridge, UK) using Continuous Flow Analysis (CFA) or from melted discrete cut ice samples. The annual-layer markers for dating of the cores were primarily determined using nssSO4 and H2O2 summer peaks, with d18O and MSA as additional support. This research effort was carried out by the BAS Ice Core group and the established age scales will provide the foundation for multiple upcoming projects. The ice core drilling and analysis was funded by the British Antarctic Survey, Natural Environment Research Council (NERC, Cambridge, UK), part of UK research and innovation and NERC grant [NE/J020710/1]. Palmer analysis was funded by Haus der Kulturen der Welt (HKW, Berlin, Germany), in collaboration with the Anthropocene working group (AWG).

Peter 1st Island is situated in the Bellingshausen Sea, a region that has experienced considerable climate change in recent decades. Here we present data from the first firn core drilled on Peter 1st Island, spanning the period 2002-2017 CE. The record includes major ion chemistry (Br-, Cl-, SO42-, Na+, Ca2+, Mg2+) used to annual layer count the ice core and calculate the annual snow accumulation. The stable water isotope record is presented as annual averages, which are related to surface air temperatures across the Amundsen-Bellingshausen Seas, and the adjacent Antarctic Peninsula. The ice core drilling and analysis were funded by Ecole Polytechnique Federale de Lausanne, the Swiss Polar Institute, and Ferring Pharmaceuticals Inc and the British Antarctic Survey, Natural Environment Research Council (NERC, Cambridge, UK).

Here we provide the Palmer ice core Water-stable isotope (d18O, dD), sodium (23Na), and magnesium (24Mg) palaeo archives. The Palmer drill site (73.86 S, 65.46 W, 1897 m a.s.l.) is located on the southern part of the Antarctic Peninsula, Palmer Land. The core, firn and ice, were drilled in December 2012 to a depth of 133 m below the snow surface. The Palmer ice core covers 391 years, 1621-2011 C.E. The data were measured on the British Antarctic Survey Continuous Flow Analysis system in Cambridge, UK. Data is given both on depth and temporal (annual means) scales. The d18O and dD records were measured on a CFA laser spectroscopy system and the 23Na and 24Mg data were measured on the CFA ICP-MS setup. The ice core drilling and analysis were funded by the British Antarctic Survey, Natural Environment Research Council (NERC, Cambridge, UK), part of UK research and innovation and NERC grant NE/J020710/1. The Palmer analysis was funded by Haus der Kulturen der Welt (HKW, Berlin, Germany), in collaboration with the Anthropocene working group (AWG).