The dataset consists of 14 selected lines of radar data, collected from the Little Dome C region close to Concordia Station in East Antarctica. The data were collected in austral field seasons 2016-17, and 2017-18, from within the search region for the planned European project Beyond EPICA - Oldest Ice, an EU-funded 10-nation consortium project to drill an ice core that spans up to 1.5 million years of climate and atmospheric history. Radar lines were recorded using the BAS DELORES sledge-borne, over-snow, ice radar system and geolocated with a precise GPS system. This data was generated within the project Beyond EPICA - Oldest Ice (BE-OI). The project has received funding from the European Union''s Horizon 2020 research and innovation programme under grant agreement No. 730258 (BE-OI CSA). It has received funding from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number 16.0144. It is further supported by national partners and funding agencies in Belgium, Denmark, France, Germany, Italy, Norway, Sweden, Switzerland, the Netherlands and the UK. Logistic support is mainly provided by AWI, BAS, ENEA and IPEV. Collection of this data also benefited from support by the joint French-Italian Concordia Programme, which established and runs the permanent station Concordia at Dome C. We particularly acknowledge those who collected the data in the field, and assisted with the processing: Robert Mulvaney, Massimo Frezzotti, Marie Cavitte, Ed King, Carlos Martin, Catherine Ritz, Julius Rix.

This data set corresponds to the processing of data acquired by the British Antarctic Survey (BAS) airborne Synthetic Aperture Radar (SAR) PASIN2 (Polarimetric Airborne Scientific INstrument, mark 2), designed for deep ice sounding and basal 3D-mapping. The dataset includes the processed calibration data collected over the sea surface near Rothera Research Station during the Antarctic Summers campaigns in 2016/17 FISS (Filchner Ice Shelf System) and 2019/20 BEAMISH (Bed Access, Monitoring and Ice Sheet History) projects, and the processed SAR images as depth profiles in the Recovery Ice Stream near its grounding line, in 2016/17 (FISS). With multiple antennas for transmission and reception at 150-MHz central frequency, and an across-track physical array, PASIN2 resolves the ambiguities for distinguishing between scatterers from port and starboard directions. After processing several 2D SAR images (range and along-track dimensions) with transmitter-receiver pairs, the directional ambiguities are resolved, obtaining the across-track Direction of Arrival (DoA, elevation angle) estimation. Finally, from the 3D geometry of range, along-track and across-track angle, the real depths and across-track distances are estimated, regarding the case of the incorrectly assumed vertical DoA of a single SAR image. The calibration flights assessed and validated the instrument antenna patterns and processing performances. In this dataset, only the simulated and measured antenna patterns, and SAR and DoA images are included. By resolving directional ambiguities and accounting for reflector across-track location, the true ice thickness and bed elevation are obtained, thereby removing the error of the usual assumption of vertical DoA, that greatly influence the output of flow models of ice dynamics. This work was supported by NERC grant reference NE/L013444/1.

This data set presents contents of the clay minerals smectite, illite, chlorite and kaolinite analysed on the clay fraction (less than 2 micrometers) of Pleistocene-Holocene drift sediments recovered at Hole U1533D on the Amundsen Sea continental rise during IODP Exp379 with RV JOIDES Resolution in Jan-Mar 2019. The clay mineral contents are given in percentages (%) both versus expedition number, site number, hole ID, core number, drill core type (H: advanced piston corer system, X: extended core barrel system; R: rotary core barrel system), section number (sect), section half (W: work; A: archive) and depth of the top and bottom of the sample within a section or core catcher (CC) in centimetres (cm) and versus depth below seafloor (CSF-A) in metres (m). The d-values (in Angstrom) and integral breadths (IB, delta 2theta) of the clay minerals smectite and illite as well as the ratios between the areas of the 5 Angstrom and 10 Angstrom peaks of illite are also given. The clay mineral data were generated and analysed by Dr Claus-Dieter Hillenbrand (British Antarctic Survey, Cambridge, United Kingdom) and Prof Werner Ehrmann (Institute of Geophysics and Geology, University of Leipzig, Germany). Users of this dataset should cite the dataset DOI and acknowledge both the data generators (C.-D. Hillenbrand and W. Ehrmann) and the International Ocean Discovery Program (IODP). The work was funded by NERC UK-IODP Moratorium Award NE/T010975/1.

Sea ice index comprising data extracted from historical records of ship observed ice positions during Weddell Sea voyages between 1820-1843. Extracted data comprise information on the expedition ship and lead, type of document, the date on which the observation was made, the ship''s latitude and longitude at the time of the observation, comments on sea ice and sea ice present (1 if deemed present, 0 if not). Publication assisted by Leverhulme Emeritus Fellowship EM-2022-042 to Professor Grant R. Bigg: "Extending the Southern Ocean marine ice record to the eighteenth century".

The data set comprises ionospheric vorticity estimates determined from measurements of ionospheric velocity made by overlapping pairs of northern hemisphere radars in the Super Dual Auroral Radar Network (SuperDARN). The vorticity estimates are separated into data files for each pair of SuperDARN radars that contributed to the whole data set. These data cover large regions of the northern hemisphere polar ionosphere, and the locations of the vorticity estimates are presented in both geographic and Altitude-Adjusted Corrected GeoMagnetic (AACGM) co-ordinates. The data cover the interval from 2000 to 2005 inclusive. This work was funded by NERC grant reference NE/R016038/1.

We present the significant ocean surface wave heights in the Arctic and Southern Oceans from CryoSat-2 data. We use a semi-analytical model for an idealised synthetic aperture satellite radar or pulse-limited radar altimeter echo power. We develop a processing methodology that specifically considers both the Synthetic Aperture and Pulse Limited modes of the radar that change close to the sea ice edge within the Arctic Ocean. All CryoSat-2 echoes to date were matched by our idealised echo revealing wave heights over the period 2011-2019. Our retrieved data were contrasted to existing processing of CryoSat-2 data and wave model data, showing the improved fidelity and accuracy of the semi-analytical echo power model and the newly developed processing methods. We contrasted our data to in situ wave buoy measurements, showing improved data retrievals in seasonal sea ice covered seas. We have shown the importance of directly considering the correct satellite mode of operation in the Arctic Ocean where SAR is the dominant operating mode. Our new data are of specific use for wave model validation close to the sea ice edge and is available at the link in the data availability statement. NERC NE/R000654/1 Towards a marginal Arctic sea ice cover.

This dataset captures information on the diet composition and mass of chinstrap penguin stomach contents at Signy Island, from 1997 to 2020. The monitoring period occurred over four weeks each year and involved sampling adults returning to feed their chicks during the creche period. Sampling took place approximately every five days. Numbers of birds sampled on each occasion varied over the entire period of the dataset from a maximum of eight to a minimum of six, equating to an annual maximum of forty birds and an annual minimum of thirty, depending on the year. All adult penguins were sampled on their return to the colony using the stomach lavage methodology specified in CCAMLR CEMP Standards Methods A8A. The stomach samples were then weighed and categorised into krill, cephalopods, fish and non-food and identified to species level where possible. Krill carapaces and otoliths were removed and measured. Ecosystems component of BAS Polar Science for Planet Earth Programme, funded by NERC.

The banded structure of Electromagnetic Ion Cyclotron (EMIC) wave spectra and their resonant interactions with radiation belt electrons depend on the cold ion composition. However, there is a great deal of uncertainty in the composition in the inner magnetosphere due to difficulties in direct flux measurements. Here we determine the sensitivity of electron diffusion by EMIC waves to the cold ion composition. The diffusion coefficients are calculated using collocated EMIC waves spectra and plasma densities observed by Van Allen Probe Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) data, parameterised by Dst, using quasi-linear theory implemented in the Pitch-Angle Diffusion of Ions and Electrons (PADIE) code. Funding was provided by NERC Highlight Topic grant: NE/P01738X/1 (Rad-Sat), NERC grant: NE/V00249X/1 (Sat-Risk) and NERC grant: NE/R016038/1

This dataset contains the floe size distribution (FSD) data derived from multi-satellite imagery data acquired across the Arctic Ocean. Satellite imagery data includes high-resolution visible images from the USGS Global Fiducials Library (MEDEA), TerraSAR-X/TanDEM-X and Worldview-3 (WV3). The derived data contain floe size (calliper diameter), shape factor, minor/major axis, perimeter and area of the floes. This data set has been used to investigate the characteristics of the FSD during major seasonal evaluation stages of Arctic sea ice floes. The retrieval of the FSD data was done by the University of Huddersfield team. This work was funded by NERC MOSAiC program NE/S002545/1.

High-resolution hindcasts (1979-2019) of summer climate over Antarctica using the UK Met Office Unified Model (MetUM) and HIRHAM5 were conducted at the British Antarctic Survey and Danish Meteorological Institute, respectively. The hindcasts are conducted for summer 1979-2018, i.e., from December 1979 to February 2019, for December, January, February (DJF). This dataset consists of near-surface temperature output from these hindcasts at a temporal resolution of every 3 hrs. The hindcasts are contributions to the COordinated Regional Downscaling EXperiment (CORDEX) project. Both models are run over Antarctic CORDEX domains, which encompass all of Antarctica and some of the surrounding ocean, at a horizontal grid spacing of around 12 km. The near-surface temperatures are used to estimate regional surface melt "potential" over Antarctic ice shelves as a function of summertime temperature extremes and identify regions of potentially enhanced "hotspots" of melt potential based on the occurrence (and magnitude) of various temperatures. Funding was provided by the European Union''s Horizon 2020 research and innovation framework programme under Grant agreement no. 101003590 (PolarRES)