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Effects of E region nonlinear instabilities in the generation of a strong SAID channel

Joaquin Diaz Pena
Matthew Zettergren
Joshua Semeter
Michael Hirsch
Toshi Nishimura
Meers Oppenheim
Yakov Dimant
First Author's Affiliation
Boston University
Abstract text:

Ionospheric flow channels play a vital role in shaping the dynamics and structure of the ionosphere. These channels are characterized by localized and swift plasma flows, which have a profound impact on the distribution of ionospheric plasma, energy and momentum transport, as well as the interaction between the ionosphere, magnetosphere, and atmosphere. Consequently, these channels can greatly influence the behavior of the ionosphere, affecting the propagation of radio waves and the distribution of ionospheric plasma. Among these flow channels, a specific type called subauroral ion drift (SAID) flow channels occurs in the subauroral region, situated between the auroral and midlatitude regions of the ionosphere. These channels are narrow, latitudinal pathways characterized by fast westward flows, appearing during magnetically disturbed periods. Recent research has indicated that SAID channels are closely related to the formation and behavior of the Strong Thermal Emission Velocity Enhancement (STEVE) aurora. STEVE is a unique type of aurora that was initially discovered by citizen scientists and stands apart from the classic auroral oval. It manifests as a narrow ribbon of light at lower latitudes, often accompanied by a distinctive pattern of green vertical stripes resembling a "picket fence." Due to its remarkable appearance and unusual behavior, STEVE has garnered significant attention from both scientists and the public. This study employs the GEMINI3D model to simulate an extreme SAID event using a three-dimensional grid, building upon previous observations of the STEVE phenomenon. The E region is of particular importance in this investigation, as the effects of non-linear instabilities. These instabilities can significantly influence conductance, temperature, and the ambient electric field, subsequently impacting the flow channel. To address this, we have updated the GEMINI3D model to incorporate the macroscopic effects of the Farley-Buneman instability.

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Poster category
MDIT - MidLatitude Thermosphere or Ionosphere