Conjugate Photoelectron Energy Spectra Derived From Coincident FUV and Radio Measurements

J. M. Urco, F. Kamalabadi, U. Kamaci, B. J. Harding, H. U. Frey, S. B. Mende, J. D. Huba, S. L. England, T. J. Immel

Research output: Contribution to journalArticlepeer-review


We present a method for estimating incident photoelectrons' energy spectra as a function of altitude by combining global scale far-ultraviolet (FUV) and radio-occultation (RO) measurements. This characterization provides timely insights important for accurate interpretation of ionospheric parameters inferred from the recently launched Ionospheric Connection Explorer (ICON) observations. Quantification of photoelectron impact is enabled by the fact that conjugate photoelectrons (CPEs) directly affect FUV airglow emissions but not RO measurements. We demonstrate a technique for estimation of photoelectron fluxes and their spectra by combining coincident ICON and COSMIC2 measurements and show that a significant fraction of ICON-FUV measurements is affected by CPEs during the winter solstice. A comparison of estimated photoelectron fluxes with measured photoelectron spectra is used to gain further insights into the estimation method and reveals consistent values within 10–60 eV.

Original languageEnglish (US)
Article numbere2021GL095839
JournalGeophysical Research Letters
Issue number23
StatePublished - Dec 16 2021


  • ICON
  • airglow
  • conjugate photolectrons
  • energy spectra

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)


Dive into the research topics of 'Conjugate Photoelectron Energy Spectra Derived From Coincident FUV and Radio Measurements'. Together they form a unique fingerprint.

Cite this