We have produced 20-year archives of electron density measurements, at 1 hour and 10-minute integration times, by reanalysing measurements from the EISCAT UHF and VHF radars between 2001-2021. We are specifically looking at altitudes 50-200 km to capture the variability in the Mesosphere Lower Thermosphere Ionosphere (MLT-I) region. We have also separately included power profile data, providing measurements of the raw electron density which can be added (with careful assumptions) to improve data resolution at the lower altitudes. Funding was provided by NERC project NE/V018426/1 (MesoS2D)

Whistler mode chorus is an important magnetospheric wave emission playing a major role in radiation belt dynamics, where it contributes to both the acceleration and loss of relativistic electrons. In this study we compute bounce and drift averaged chorus diffusion coefficients for 3.0 < L* < 6.0, using the TS04 external magnetic field model, taking into account co-located near-equatorial measurements of the wave intensity and fpe/fce, by combining the Van Allen probes measurements with data from a multi-satellite VLF wave database. The variation of chorus wave normal angle with spatial location and fpe/fce is also taken into account. We find that chorus propagating at small wave normal angles has the dominant contribution to the diffusion rates in most MLT sectors. However, in the region 4 <= MLT < 11 high wave normal angles dominate at intermediate pitch angles. In the region 3 < L* < 4, the bounce and drift averaged pitch angle and energy diffusion rates during active conditions are primarily larger than those in our earlier models by up to a factor of 10 depending on energy and pitch angle. Further out, the results are similar. We find that the bounce and drift averaged energy and pitch angle diffusion rates can be significantly larger than the new model in regions of low fpe/fce,eq, where the differences can be up to a factor of 10 depending on energy and pitch angle. Funding was provided by the Natural Environment Research Council (NERC) Highlight Topic grant NE/P01738X/1 (Rad-Sat) and the NERC grants NE/V00249X/1 (Sat-Risk), NE/R016038/1 and NE/X000389/1.

The data files in this directory were used to create Figures 2-7 in the paper: Horne et al. (in press - 2018/7/18). Figure 1 of the paper was constructed using publically available data from other sources.

We conduct a global survey of magnetosonic waves and compute the associated bounce and drift averaged diffusion coefficients, taking into account co-located measurements of fpe/fce, to assess the role of magnetosonic waves in radiation belt dynamics, where fpe is the plasma frequency and fce is the electron gyrofrequency.. The average magnetosonic wave intensities increase with increasing geomagnetic activity and decreasing relative frequency with the majority of the wave power in the range fcp < f < 0.3fLHR during active conditions, where fcp is the proton gyrofrequency and fLHR is the lower hybrid resonance frequency. In the region 4.0 <= L* <= 5.0, the bounce and drift averaged energy diffusion rates due to magnetosonic waves never exceed those due to whistler mode chorus, suggesting that whistler mode chorus is the dominant mode for electron energisation to relativistic energies in this region. Further in, in the region 2.0 <= L* <= 3.5, the bounce and drift averaged pitch angle diffusion rates due to magnetosonic waves can exceed those due to plasmaspheric hiss and very low frequency (VLF) transmitters over energy-dependent ranges of intermediate pitch angles. We compute electron lifetimes by solving the 1D pitch angle diffusion equation including the effects of plasmaspheric hiss, VLF transmitters and magnetosonic waves. We find that magnetosonic waves can have a significant effect on electron loss timescales in the slot region reducing the loss timescales during active times from 5.6 to 1.5 days for 500 keV electrons at L* = 2.5 and from 140.4 days to 35.7 days for 1 MeV electrons at L* = 2.0. The research leading to these results has received funding from the Natural Environment Research Council (NERC) Highlight Topic grant NE/P01738X/1 (Rad-Sat) and the NERC grants NE/V00249X/1 (Sat-Risk) and NE/R016038/1.

Signals from manmade VLF transmitters, used for communications with submarines, can leak into space and contribute to the dynamics of energetic electrons in the inner radiation belt and slot region. We use ~5 years of plasma wave data from the Van Allen Probe A satellite to construct new models of the observed wave power from VLF transmitters both as a function of L* and MLT and geographic location. This work is reported in Meredith et al. (2019) and the data provided here enable reconstruction of all of the figures in the paper.

Auroral oval boundary locations derived from IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) satellite FUV (Far Ultra Violet imager) data covering the period from May 2000 until October 2002. Three sets of boundary data were derived separately from the WIC (Wideband Imaging Camera) and SI12/SI13 (Spectrographic Imager 121.8/135.6 nm) detectors. For each image, the position of each pixel in AACGM (Altitude Adjusted Corrected Geomagnetic) coordinates was established. Each image was then divided into 24 segments covering 1 hour of magnetic local time (MLT). For each MLT segment, an intensity profile was constructed by finding the average intensity across bins of 1 degree magnetic latitude in the range of 50 to 90 degrees (AACGM). Two functions were fit to each intensity profile: a function with one Gaussian component and a quadratic background, and a function with two Gaussian components and a quadratic background. The function with a single Gaussian component should provide a reasonable model when the auroral emission forms in a continuous oval. When the oval shows bifurcation, the function with two Gaussian components may provide a better model of the auroral emission. Of the two functions fit to each intensity profile, we determine the one with the lower reduced chi-square goodness-of-fit statistic to be the better model for that profile. For the version 1.1 boundary location data, the fitting process was performed over 200 iterations to achieve each fit. The auroral boundaries were then determined to be the position of the peak of the poleward Gaussian curve, plus its FWHM (full-width half-maximum) value of the Gaussian, to the peak of the equatorward Gaussian, minus its FWHM. In the case of the single Gaussian fit, the same curve is used for both boundaries. A number of criteria were applied to discard poorly located auroral boundaries arising from either poor fitting or incomplete data. A further correction can be applied to the data, to estimate the location of the Earth's magnetic field's OCB (open-close boundary). These corrections have been tabulated in a separate file; if this correction is required the adjustments should be made to the poleward boundary value.

These files contain the data from the figures in "A 30 year simulation of the outer electron radiation belt", S.A. Glauert, et al., Space Weather 2018. The paper describes a 30 year (1 January 1986 - 1 January 2016) reconstruction of the Earth's electron radiation belt from L*=2 to L*=6.1 (approximately geostationary orbit), for energies ranging from 100 keV to 30 MeV at L*=6.1.

We present a reanalysis of SuperDARN plasma velocity measurements, using the method of data-interpolating Empirical Orthogonal Functions (EOFs). The northern polar region's radar-measured line of sight Doppler velocities are binned in an equal-area grid (areas of approximately 110,000km2) in quasi-dipole latitude and quasi-dipole magnetic local time (MLT). Within this spatial grid, which extends to 30 degrees colatitude, the plasma velocity is given in terms of cardinal north and east vector components (in the quasi-dipole coordinate frame), with the median of every SuperDARN measurement in the spatial bin taken every 5 minutes. These sparse binned data are infilled to provide a measurement at every spatial and temporal location via EOF analysis, ultimately comprising a reanalysis spanning the month of February 2001. This resource provides a convenient method of using SuperDARN data without its usual extreme sparseness, for studies of ionospheric electrodynamics. The reanalysis is provided in sets of orthogonal modes of variability (spatial and temporal patterns), along with the timestamps of each epoch, and the spatial coordinate information of all bin locations. We also provide the temporal mean of the data in each spatial bin, which is removed prior to the EOF analysis. Funding was provided by NERC standard grants NE/N01099X/1 (THeMES) and NE/V002732/1 (SWIMMR-T).

This dataset contains the data produced by four Gorgon Global magnetohydrodynamic (MHD) simulations of Fast-Forward Interplanetary Shocks of increasing strengths interacting with the Earth's magnetosphere, as described in the study of Desai et al. (2021). Further description of the Gorgon MHD model can be found at Mejnertsen et al., (2016,2018) and Eggington et al., (2020). The data was produced on the Imperial College High Performance Computing Service (doi: 10.14469/hpc/2232). The MHD equations were solved in the magnetosphere on a regular 3-D cartesian grid of resolution 0.5 Earth radii (RE), covering a domain of dimensions (-20,100) RE in X, (-40,40) RE in Y and (-40,40) RE in Z with an inner boundary at 3 RE. In this coordinate system the Sun lies in the negative X-direction, the Z axis is aligned to the dipole in the 0 degree tilt case (where positive tilt points the north magnetic pole towards the Sun), and Y completes the right-handed set. Output data is timestamped in seconds and is defined at the centre of the grid cells. The simulation data corresponding to each shock are stored in separate directories 'ShockX' where X=I-IV. The data are stored in hdf5 format. The magnetospheric variables are stored in the files: 'Gorgon_[YYYYMMDD]_MS_params_[XXXXX]s.hdf5' where XXXXX is the simulation time in seconds. The magnetospheric data includes the magnetic field, ('Bvec_c'), velocity, ('vvec'), plasma density, ('rho1'), and ion temperature, ('Ti'), after 2h of simulation, over the course of 10 minutes. The data for the magnetic field, ('Bvec_c'), and velocity, ('vvec'), are of shape (240,160,160,3) where the first 3 dimensions are the grid indices in (X,Y,Z) indexed from negative to positive, and the final dimension is the cartesian vector component in (i,j,k). The data for the density, ('rho1'), and ion temperature, ('Ti'), is of shape (240,160,160) where the first 3 dimensions are the grid indices in (X,Y,Z) indexed from negative to positive. Funding was provided by NERC Highlight grant to NE/P017347/1 (Rad-Sat)

This dataset contains data produced by two Gorgon Global magnetohydrodynamic (MHD) simulations with steady solar wind conditions interacting with the Earth's magnetosphere, as utilised in the study of Desai et al. (2021b). Further description of the Gorgon MHD model can be found at Mejnertsen et al., (2016,2018), Eggington et al., (2020) and Desai et al., (2021a). The data was produced on the Imperial College High Performance Computing Service (doi: 10.14469/hpc/2232). Two MHD simulations are contained; one with northward Interplanetary Magnetic Field (IMF) conditions and one with southward (IMF) conditions. The northward IMF condition is run with a grid resolution of 0.25 earth radii (RE) and the southward IMF conditions is run three times for grid resolutions of 0.5, 0.25 and 0.125 RE. The MHD equations were solved in the magnetosphere on a regular 3-D Cartesian grid, covering a domain of dimensions (-20,100) RE in X, (-40,40) RE in Y and (-40,40) RE in Z with an inner boundary at 3 RE. In this coordinate system the Sun lies in the negative X-direction, the Z axis is aligned to the dipole in the 0 degree tilt case (where positive tilt points the north magnetic pole towards the Sun), and Y completes the right-handed set. Output data is timestamped in seconds and is defined at the centre of the grid cells. The simulation data corresponding to each shock are stored in separate directories 'NorthwardX' and 'SouthwardX' where X is the grid resolution in RE of: 0.5 for the northward case and 0.5, 0.25 and 0.125 for the southward case. The data are stored in hdf5 format. The magnetospheric variables are stored in the files: 'Gorgon_[YYYYMMDD]_MS_params_[XXXXX]s.hdf5' where XXXXX is the simulation time in seconds. The magnetospheric data includes the magnetic field, ('Bvec_c') and Electric field, ('Evec'), after 2hrs of simulation. The data are of shape (240,160,160,3) where the first 3 dimensions are the grid indices in (X,Y,Z) indexed from negative to positive, and the final dimension is the cartesian vector component in (i,j,k). Funding was provided by NERC Highlight grant to NE/P017347/1 (Rad-Sat).