Electrons in the outer Van Allen (radiation) belt occasionally reach relativistic energies, turning them into a potential hazard for spacecraft operating in geospace. Such electrons have secured the reputation of satellite killers and play a prominent role in space weather. The flux of these electrons can vary over time scales of years (related to the solar cycle) to minutes (related to sudden storm commencements). Electric fields and plasma waves are the main factors regulating the electron transport, acceleration and loss. Both the fields and the plasma waves are driven directly or indirectly by disturbances originating in the Sun, propagating through interplanetary space and impacting the Earth. This paper reviews our current understanding of the response of outer Van Allen belt electrons to solar eruptions and their interplanetary extensions, i.e. interplanetary coronal mass ejections and high-speed solar wind streams and the associated stream interaction regions.

Solar proton flux measurements onboard Geostationary Operational Environmental Satellites (GOES) are of great importance as they cover several solar cycles, increasingly contributing to the development of long-term solar proton models and to operational purposes such as now-casting and forecasting of space weather. A novel approach for the cross calibration of GOES solar proton detectors is developed using as reference energetic solar proton flux measurements of NASA IMP-8 Goddard Medium Energy Experiment (GME). The spurious behavior in a part of IMP-8/GME measurements is reduced through the derivation of a nonlinear intercalibration function. The effective energy values of GOES solar proton detectors lead to a significant reduction of the uncertainties in spectra and may be used to refine existing scientific results, available models, and data products based on measurements over the last three decades. The methods presented herein are generic and may be used for calibration processes of other data sets as well.