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The X-pattern Merging of the Equatorial Ionization Anomaly Crests
  • +7
  • Fazlul I Laskar,
  • Deepak Kumar Karan,
  • Robert Edward Daniell,
  • Mihail V. Codrescu,
  • Richard W Eastes,
  • Nicholas Michael Pedatella,
  • Wenbin Wang,
  • Astrid Maute,
  • P. K. Rajesh,
  • William E. McClintock
Fazlul I Laskar
Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA

Corresponding Author:[email protected]

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Deepak Kumar Karan
Laboratory for Atmospheric and Space Physics, University of Colorado
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Robert Edward Daniell
Ionospheric Physics Consulting
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Mihail V. Codrescu
Space Weather Prediction Center, NOAA, Boulder, CO, USA
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Richard W Eastes
Laboratory for Atmospheric and Space Physics
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Nicholas Michael Pedatella
National Center for Atmospheric Research (UCAR)
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Wenbin Wang
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Astrid Maute
CIRES/ University of Colorado Boulder
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P. K. Rajesh
National Cheng Kung University
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William E. McClintock
Laboratory for Atmospheric and Space Physics
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A unique phenomenon {\textendash} merging of Equatorial Ionization Anomaly (EIA) crests, leading to an X-pattern (EIA-X) around the magnetic equator {\textendash} has been observed in the night-time ionospheric measurements by the Global-scale Observations of the Limb and Disk (GOLD) mission. A whole atmospheric general circulation model simulation reproduces this pattern. The pattern is also produced in an assimilative ionosphere model that assimilates slant Total Electron Content (slant-TEC) from Global Navigation Satellite System (GNSS) and Constellation Observing System for Meteorology, Ionosphere, and Climate 2 (COSMIC-2). Due to the observed similarity between measurements and simulations, the latter is used to diagnose this heretofore unexplained phenomenon. The simulation shows that the EIA-X occurs in the afternoon to evening sector at a longitude where the vertical drift is negative, which is a necessary but not sufficient condition. The simulation was performed under constant low-solar and quiescent-geomagnetic forcing conditions, therefore we suggest that one of the drivers of this phenomenon is from lower-atmospheric processes.
30 Oct 2023Submitted to ESS Open Archive
08 Nov 2023Published in ESS Open Archive