Version 2.0 This data set contains mesospheric carbon monoxide (CO) data acquired by the ground-based microwave radiometer of the British Antarctic Survey (BAS radiometer) stationed at Troll station in Antarctica (72 deg S, 2.5 deg E, 1270 amsl). The BAS radiometer has been designed in order to study the effects of energetic particle precipitation on the middle and upper atmosphere, using nitric oxide and ozone measurements. This data set contains the CO measurements carried out in order to study the dynamical context. The data set covers the period from February 2008 to January 2010, however, due to very low CO concentrations below approximately 80 km altitude in summer, profiles can only be retrieved during Antarctic winter. CO is measured for approximately 2 hours each day (80 percent of the profiles are within +-2 hours around local noon) and profiles are retrieved approximately every half hour. The retrieved profiles, cover two independent layers in the pressure range from 1 to 0.01 hPa (approximately 48 to 80 km, altitude resolution of approximately 16 km). In this version of the data; an additional column of "apriori vmr" has been included in the data files.

Version 1.0 This data set contains mesospheric carbon monoxide (CO) data acquired by the ground-based microwave radiometer of the British Antarctic Survey (BAS radiometer) stationed at Troll station in Antarctica (72 deg S, 2.5 deg E, 1270 amsl). The BAS radiometer has been designed in order to study the effects of energetic particle precipitation on the middle and upper atmosphere, using nitric oxide and ozone measurements. This data set contains the CO measurements carried out in order to study the dynamical context. The data set covers the period from February 2008 to January 2010, however, due to very low CO concentrations below approximately 80 km altitude in summer, profiles can only be retrieved during Antarctic winter. CO is measured for approximately 2 hours each day (80 percent of the profiles are within +-2 hours around local noon) and profiles are retrieved approximately every half hour. The retrieved profiles, cover two independent layers in the pressure range from 1 to 0.01 hPa (approximately 48 to 80 km, altitude resolution of approximately 16 km).

This dataset contains mesospheric ozone (O3) data acquired by the ground-based British Antarctic Survey's Microwave Radiometer at Troll (BAS-MRT) in Antarctica (72 deg S, 2.5 deg E, 1270 amsl). The BAS radiometer has been designed in order to study the effects of energetic particle precipitation on the middle and upper atmosphere, using nitric oxide and ozone measurements, and the dynamical context using CO. This data set contains the O3 measurements. The data set covers the period from February 2008 to January 2010. O3 is measured for approximately 20 hours each day and profiles are retrieved every hour. The retrieved profiles cover the pressure range from 3 to 0.02 hPa (approximately 38 to 72 km), with an altitude resolution that varies from 10 km at 3 hPa (39 km) to 18 km at 0.7 hPa (66~km).

A netcdf-formatted file containing the original binned data (described in Shore et al [2017]), in their state before they were subjected to EOF analysis. These have had additional processing applied to the SuperMAG data (publically available at http://supermag.jhuapl.edu/) in the form of sampling them to the centroid of the bins, thus they are worth providing here despite the large file size (approximately 12GB). To conserve file space, we have removed empty bins, thus the temporal and spatial basis for these data are provided for each filled bin element. Please note that the binned data had not had the temporal mean values (described in Shore et al [2017], and available in the Supporting Information) removed when they were stored in this netcdf file. The file contains 144 (monthly) sets of 8 variables. These variables are named: 1: filled_bin_data_YYYYMM_r 2: filled_bin_data_YYYYMM_theta 3: filled_bin_data_YYYYMM_phi Variables 1 to 3 contain the nanoTesla vales of the binned data for each of the three magnetic field components in the Quasi-Dipole frame. 4: filled_bin_contrib_stations_YYYYMM The three-letter SuperMAG acronym of the station which contributed to each 5-minute mean data point. 5: filled_bin_colats_YYYYMM 6: filled_bin_longs_YYYYMM Variables 5 and 6 are the co-latitude and longitude coordinates of each filled bin element. 7: filled_bin_times_YYYYMM The 5-minute-mean epoch of each filled bin element, with columns in the order: year, month, day, hour, minute, second). 8: filled_bin_indices_YYYYMM A set of fiducial values describing how the sparse elements of the 1D vector of filled bin values relate to the fiducials of the (transposed!) EOF prediction a 2D matrix product of the spatial and temporal eigenvectors with values in every bin. An example of the usage of these data is given in the MATLAB program Shore-ms01.m, provided in the Supporting Information of Shore et al [2017]. ***** PLEASE BE ADVISED TO USE VERSION 2.0 DATA ***** The VERSION 2.0 data set has been corrected for a bug which led to the bins which span the local midnight meridian having fewer samples than they should. The data density in these bins is now in-line with the rest of the polar coverage. Apart from that change, the original and updated data sets are the same.

A netcdf-formatted file containing the original binned data (described in Shore et al [2017]), in their state before they were subjected to EOF analysis. These have had additional processing applied to the SuperMAG data (publically available at http://supermag.jhuapl.edu/) in the form of sampling them to the centroid of the bins, thus they are worth providing here despite the large file size (approximately 12GB). To conserve file space, we have removed empty bins, thus the temporal and spatial basis for these data are provided for each filled bin element. Please note that the binned data had not had the temporal mean values (described in Shore et al [2017], and available in the Supporting Information) removed when they were stored in this netcdf file. The file contains 144 (monthly) sets of 8 variables. These variables are named: 1: filled_bin_data_YYYYMM_r 2: filled_bin_data_YYYYMM_theta 3: filled_bin_data_YYYYMM_phi Variables 1 to 3 contain the nanoTesla vales of the binned data for each of the three magnetic field components in the Quasi-Dipole frame. 4: filled_bin_contrib_stations_YYYYMM The three-letter SuperMAG acronym of the station which contributed to each 5-minute mean data point. 5: filled_bin_colats_YYYYMM 6: filled_bin_longs_YYYYMM Variables 5 and 6 are the co-latitude and longitude coordinates of each filled bin element. 7: filled_bin_times_YYYYMM The 5-minute-mean epoch of each filled bin element, with columns in the order: year, month, day, hour, minute, second). 8: filled_bin_indices_YYYYMM A set of fiducial values describing how the sparse elements of the 1D vector of filled bin values relate to the fiducials of the (transposed!) EOF prediction a 2D matrix product of the spatial and temporal eigenvectors with values in every bin. An example of the usage of these data is given in the MATLAB program Shore-ms01.m, provided in the Supporting Information of Shore et al [2017]. ***** PLEASE BE ADVISED TO USE VERSION 2.0 DATA ***** The VERSION 2.0 data set (see 'Related Data Set Metadata' link below) has been corrected for a bug which led to the bins which span the local midnight meridian having fewer samples than they should. The data density in these bins is now in-line with the rest of the polar coverage. Apart from that change, the original and updated data sets are the same.

Two netcdf files are provided that contain daily precipitation amounts for January 1979 - July 2017 from the RACMO version 3p2 limited area, atmosphere-only model. The model is described in van Wessem, J. M., C. H. Reijmer, M. Morlighem, J. Mouginot, E. Rignot, B. Medley, and E. van Meijgaard, (2014) Improved representation of East Antarctic surface mass balance in a regional atmospheric climate model, Journal of Glaciology, 60, 761-770. The model was run over a 262 by 240 grid point domain covering Antarctica and parts of the Southern Ocean. The model was forced at the lateral boundaries by data from the European Centre for Medium-range Weather Forecasting (ECMWF) Interim reanalysis (ERA-Interim). Flags are provided for extreme precipitation events. A precipitation day was taken as a daily total of precipitation of greater than 0.02 mm. Extreme precipitation events were then taken as days when daily precipitation amount was greater than the 90th percentile of the daily precipitation values over the period 1979 - 2016.

Relativistic electrons in the Earth's outer radiation belt are a significant space weather hazard. Satellites in GPS-type orbits pass through the heart of the outer radiation belt where they may be exposed to large fluxes of relativistic electrons. In this study we conduct an extreme value analysis of the daily average relativistic electron flux in GPS orbit as a function of energy and L using data from the US NS41 satellite from 10 December 2000 to 25 July 2020. The 1 in 10 year flux at L=4.5, in the heart of the outer radiation belt, decreases with increasing energy ranging from 8.2x10^6 cm^-2s^-1sr^-1MeV^-1 at E = 0.6 MeV to 33 cm^-2s^-1sr^-1MeV^-1 at E = 8.0 MeV. The 1 in 100 year is a factor of 1.1 to 1.7 larger than the corresponding 1 in 10 year event. The 1 in 10 year flux at L=6.5, on field lines which map to the vicinity of geostationary orbit, decrease with increasing energy ranging from 6.2x10^5 cm^-2s^-1sr^-1MeV^-1 at E = 0.6 MeV to 0.48 cm^-2s^-1sr^-1MeV^-1 at E = 8.0 MeV. Here, the 1 in 100 year event is a factor of 1.1 to 13 times larger than the corresponding 1 in 10 year event, with the value of the factor increasing with increasing energy. Our analysis suggests that the fluxes of relativistic electrons with energies in the range 0.6 <= E <= 2.0 MeV in the region 4.25 <= L <= 4.75 have an upper bound. In contrast, further out and at higher energies the fluxes of relativistic electrons are largely unbounded. The research leading to these results has received funding from the Natural Environment Research Council (NERC) grants NE/V00249X/1 (Sat-Risk) and NE/R016038/1.

Airborne and model data collected during the ACCACIA - Aerosol-Cloud Coupling And Climate Interactions in the Arctic project. The dataset comprises airborne in situ measurements of cloud microphysical properties, the vertical structure of the boundary layer and aerosol properties, and the fluxes of solar and infra red radiation above, below, and within cloud. Data was collected on board the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft and the British Antarctic Survey (BAS) Masin aircraft. It also contains data from specially configured Met Office Unified Model runs. AMS and SP2 data measured on board the Research Ship James Clark Ross during ACCACIA is also available. This project is part of the NERC Arctic research programme. (NERC Reference: NE/I028858/1).

This dataset contains solution data produced by the BAS-PRO proton radiation belt model for the study "Modelling Inner Proton Belt Variability at Energies 1 to 10MeV using BAS-PRO". The solution data is in the form of 3D grids describing phase space density computed during dynamic simulations of Earth's proton belt over the modelling period 2014 to 2018. Three model runs are included: SA19, J81 and S16. Files were produced in May 2021. This work was funded by the Natural Environment Research Council (NERC) via Doctoral Training Programme NE/R009457/1. Richard B. Horne and Sarah A. Glauert were supported by NERC National Capability grants NE/R016038/1 and NE/R016445/1, and by NERC grant NE/V00249X/1 (Sat-Risk), and by Highlight Topic Grant NE/P01738X/1 (Rad-Sat). Giulio Del Zanna acknowledges support from STFC (UK) via the consolidated grants to the atomic astrophysics group (AAG) at DAMTP, University of Cambridge (ST/P000665/1 and ST/T000481/1). Seth G. Claudepierre acknowledges support from NASA Grant no. NNX17AF10G and from RBSP-ECT funding provided by JHU/APL Contract 967399 under NASA's Prime Contract NAS5-01072.

The data consists of a CSV file of mean sea level pressure (MSLP, in hPa), 1.25 m temperature (in celsius), 10 m wind speed (in knots), 10 m wind direction (in degrees), and relative humidity (in percent) measured at Signy Station (Latitude 60 degress 43'0"S, Longitude 45 degrees 36'0"W) for the period of 1947 - 1994. These data were used by Lu et al. (2023) to study extreme high temperature events in the South Orkney Islands (SOIs). Funding was provided by the Natural Environment Research Council (NERC) to the Atmosphere, Ice and Climate Programme of British Antarctic Survey (BAS), NERC National Capability International grant SURface FluxEs In AnTarctica (NE/X009319/1) and the European Union's Horizon 2020 research and innovation framework programme under Grant agreement no. 101003590 (PolarRES).