Cross‐Calibration of Energetic Electron Flux Measurements From the Cluster and THEMIS Missions

Abstract Energetic electrons in Earth's magnetosphere play a critical role in space weather processes and pose risks to spacecraft electronics. Combining measurements from multiple missions, such as Cluster and Time History of Events and Macroscale Interactions during Substorms (THEMIS), enhances our understanding of these populations but requires cross‐calibration due to instrumental differences. This study presents a statistical comparison of 40–400 keV electron flux measurements from Cluster/Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) and THEMIS/Solid State Telescope (SST) over 2007–2018. By analyzing the statistical distance between local flux distributions, we quantify discrepancies between the data sets and derive cross‐calibration factors, covering radial distances up to 16 . Our results show that SST fluxes consistently exceed IES observations, with the difference increasing with energy. The derived correction factors enable the joint use of the Cluster and THEMIS energetic electron data for multipoint space weather studies.