Turbulence Embedded Into the Ionosphere by Electromagnetic Waves

• Published in: Journal of geophysical research. Space physics 2024-08, Vol.129 (8), p.n/a
• Main Authors: Ivarsen, Magnus F., Gillies, Megan D., Huyghebaert, Devin R., St‐Maurice, Jean‐Pierre, Lozinsky, Adam, Galeschuk, Draven, Donovan, Eric, Hussey, Glenn C.
• Format: Article
• Language: English
• Subjects: aurora; Auroras; Charge deposition; Charged particles; Chorus waves; Cosmology; Earth magnetosphere; Electric fields; Electromagnetic radiation; Electron precipitation; Electrons; Embedding; Ionosphere; magnetosphere; Neutral gases; Pressure gradients; pulsating; Radar; Structural stability; Turbulence; Wave interaction
• ISSN: 2169-9380; 2169-9402; 2169-9402
• DOI: 10.1029/2023JA032310

When charged particles are accelerated from Earth's magnetosphere and precipitate into the atmosphere, their impact with neutral gas creates the aurora. Structured electric fields drive the acceleration processes but they are also passed down to the ionosphere, meaning that turbulence can in part be embedded into the ionosphere rather than emerge through instability processes locally. Applying a point‐cloud analysis technique adapted from observational cosmology, we show how observed turbulence in the ionosphere matches electrical current signatures in the pulsating aurora in a series of conjunctions between space‐ and ground‐based instruments. We propose that the temporal spectrum of pulsations in the pulsating aurora is the driver of a clearly observed energy injection into the ionosphere's unstable bottomside. Precipitating electrons produce electric fields through charge deposition, and we observe wave characteristics that are present in this pattern. Next, the relative electron‐ion drifts excite the Farley‐Buneman instability, the distribution of whose waves are organized according to the local electric field. It is the temporal characteristics of chorus wave interactions in the magnetosphere that is imparted, via precipitating electrons, to the pulsating aurora, and so we propose that chorus wave interactions are capable of embedding turbulent structure into the ionosphere. This structure (now pressure gradients) dissipate energy in the E‐region through turbulent processes, observed by the icebear coherent scatter radar. Key Points A study of multiple space‐ground conjunctions that occurred during a strong pulsating aurora event There were identical turbulent properties in in‐situ field‐structuring and in E‐region plasma turbulence We suggest that this structure is driven, or embedded, by electromagnetic waves, mediated by precipitating particles in the pulsating aurora