Electron variability at geosynchronous orbit plays a key role in satellite operations especially concerning the low energies which can lead to surface charging effects on spacecraft. In this work, we use 9 years (2011-2019) of electron measurements from GOES-13, 14 and 15 satellites to study the evolution of electron uxes with various solar, solar wind and magnetospheric parameters. The source electron fluxes are shown to be well correlated with AE index and Newell’s function, while the seed electron fluxes are shown to be well correlated with solar wind speed. Based on these findings, we have developed a predictive multiple regression model for electron fluxes in the 30-350 keV energy range which uses solely solar wind parameters’ measurements. The model may have a variety of applications related nowcasting/forecasting of the distribution of electron fluxes at GEO including serving as low-energy boundary conditions for studying electron acceleration to relativistic energies or providing information for predicting surface and/or internal charging effects on spacecraft.

The Earth’s outer radiation belt response to geospace disturbances is extremely variable spanning from a few hours to several months. In addition, the numerous physical mechanisms, which control this response, depend on the electron energy, the time-scale and the various types of geospace disturbances. As a consequence, the various models that currently exist are either specialized, orbit-specific data-driven models, or sophisticated physics-based ones. In this paper we present a new approach for radiation belt modelling using Machine Learning methods driven solely by solar wind speed and pressure, Solar flux at 10.7 cm and the $\theta$ angle controlling the Russell-McPherron effect. We show that the model can successfully reproduce and predict the electron fluxes of the outer radiation belt in a broad energy (0.033–4.062 MeV) and L-shell (2.5–5.9) range and, moreover, it can capture the long-term modulation of the semi-annual variation. We also show that the model can generalize well and provide successful predictions, even outside of the spatio-temporal range it has been trained with, using >0.8 MeV electron flux measurements from GOES-15/EPEAD at geostationary orbit.

Accurate measurements of trapped energetic electron fluxes are of major importance for the studies of the complex nature of radiation belts and the characterization of space radiation environment. The harmonization of measurements between different instruments increase the accuracy of scientific studies and the reliability of data-driven models that treat the specification of space radiation environment. An inter-calibration analysis of the energetic electron flux measurements of the Magnetic Electron Ion Spectrometer (MagEIS) and the Relativistic Electron-Proton Telescope (REPT) instruments on-board the Radiation Belt Storm Probes (RBSP) versus the measurements of the Extremely High Energy Electron Experiment (XEP) unit on-board Arase (ERG) mission is presented. The performed analysis demonstrates a remarkable agreement between the majority of MagEIS and XEP measurements and suggests the re-scaling of MagEIS HIGH unit and of REPT measurements for the treatment of flux spectra discontinuities. The proposed adjustments were validated successfully using measurements from ESA Environmental Monitoring Unit (EMU) on-board GSAT0207 and the Standard Radiation Monitor (SREM) on-board INTEGRAL. The derived results lead to the harmonization of science-class experiments on-board RBSP (2012-2019) and Arase (2017- ) and propose the use of the datasets as reference in a series of space weather and space radiation environment developments.

We report observations of a magnetosheath jet followed by a period of decelerated background plasma. During this period, THEMIS-A magnetometer showed abrupt disturbances which, in the wavelet spectrum, appeared as prominent and irregular pulsations in two frequency bands (7.6–9.2 and 12–17 mHz) within the Pi2 range. The observations suggest–for the first time to our knowledge–that these pulsations were locally generated by the abrupt magnetic field changes driven by the jet’s interaction with the ambient magnetosheath plasma. Furthermore, similar pulsations, detected by THEMIS-D inside the magnetosphere with a 140 seconds time-lag (which corresponds to the propagation time of a disturbance travelling with Alfvenic speed), are shown to be directly associated with the ones in the magnetosheath, which raises the question of how exactly these pulsations are propagated through the magnetopause.