New global loss model of energetic and relativistic electrons based on Van Allen Probes measurements

TitleNew global loss model of energetic and relativistic electrons based on Van Allen Probes measurements
Publication TypeJournal Article
Year of Publication2016
AuthorsOrlova, K, Shprits, Y, Spasojevic, M
JournalJournal of Geophysical Research: Space Physics
Date Published02/2016
KeywordsGlobal Positioning System; Van Allen Probes
AbstractEnergetic electron observations in Earth's radiation belts are typically sparse and multi-point studies often rely on serendipitous conjunctions. This paper establishes the scientific utility of the Combined X-ray Dosimeter (CXD), currently flown on 19 satellites in the Global Positioning System (GPS) constellation, by cross-calibrating energetic electron measurements against data from the Van Allen Probes. By breaking our cross-calibration into two parts – one that removes any spectral assumptions from the CXD flux calculation, and one that compares the energy spectra – we first validate the modeled instrument response functions, then the calculated electron fluxes. Unlike previous forward modeling of energetic electron spectra we use a combination of four distributions that, together, capture a wide range of observed spectral shapes. Our two-step approach allowed us to identify, and correct for, small systematic offsets between block IIR and IIF satellites. Using the Magnetic Electron Ion Spectrometer (MagEIS) and Relativistic Electron-Proton Telescope (REPT) on Van Allen Probes as a “gold standard” we demonstrate that the CXD instruments are well-understood. A robust statistical analysis shows that CXD and Van Allen Probes fluxes are similar and the measured fluxes from CXD are typically within a factor of 2 of Van Allen Probes at energies ≲4 MeV. We present data from 17 CXD-equipped GPS satellites covering the 2015 “St. Patrick's Day” geomagnetic storm to illustrate the scientific applications of such a high data density satellite constellation, and therefore demonstrate that the GPS constellation is positioned to enable new insights in inner magnetospheric physics and space weather forecasting.
URLhttp://doi.wiley.com/10.1002/2015JA021878
DOI10.1002/2015JA021878
Short TitleJ. Geophys. Res. Space Physics


Page Last Modified: February 19, 2016