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ORIGINAL RESEARCH article

Front. Astron. Space Sci.
Sec. Space Physics
Volume 11 - 2024 | doi: 10.3389/fspas.2024.1434367

Global Empirical Model of Sporadic-E Occurrence Rates (GEMSOR)

Provisionally accepted
Eli Parsch Eli Parsch 1*Anthony L. Franz Anthony L. Franz 2Eugene V. Dao Eugene V. Dao 3Dong Wu Dong Wu 4Nimalan Swarnalingam Nimalan Swarnalingam 4Cornelius C. Salinas Cornelius C. Salinas 4Daniel J. Emmons Daniel J. Emmons 2*
  • 1 United States Air Force Academy, Colorado Springs, Colorado, United States
  • 2 Air Force Institute of Technology, Wright-Patterson AFB, United States
  • 3 Space Vehicles Directorate, Air Force Research Laboratory, Albuquerque, New Mexico, United States
  • 4 Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, Maryland, United States

The final, formatted version of the article will be published soon.

    Intense ionization enhancements in the Earth's ionosphere known as sporadic-E (Es ), can degrade and severely disrupt the propagation of radio signals. Although many previous studies have analyzed the characteristics and morphologies of sporadic E, few efforts have attempted to model global E s occurrence rates (OR) at high time resolutions. This study develops a global empirical model of blanketing sporadic-E occurrence rates using a Karhunen-Loéve Expansion (KLE) of a global OR climatology built with Global Navigation Satellite System Radio Occultation (GNSS-RO) and ionosonde observations. Using an fbEs ≥ 3 MHz threshold, the model outputs a blanketing sporadic-E OR for a given geomagnetic latitude, longitude, day of year, and local solar time. The model outputs are compared to Digisonde observations at four sites with varying geomagnetic latitudes, resulting in correlation coefficients ranging from 0.5 to 0.9 for monthly averaged observations and an uncertainty of 11%. Furthermore, the average uncertainty is estimated to be 12%. This Global Empirical Model of Sporadic-E Occurrence Rates (GEMSOR) is capable of providing blanketing sporadic-E OR estimates for global radio frequency (RF) operations.

    Keywords: Ionosphere, Sporadic-E, Radio occultation, Global climatology, Karhunen-Lo éve expansion

    Received: 17 May 2024; Accepted: 15 Oct 2024.

    Copyright: © 2024 Parsch, Franz, Dao, Wu, Swarnalingam, Salinas and Emmons. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Eli Parsch, United States Air Force Academy, Colorado Springs, 80840, Colorado, United States
    Daniel J. Emmons, Air Force Institute of Technology, Wright-Patterson AFB, United States

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.