Partamies, Noora;
Dayton-Oxland, Rowan;
Herlingshaw, Katie;
Virtanen, Ilkka;
Gallardo-Lacourt, Bea;
Syrjasuo, Mikko;
Sigernes, Fred;
... Ledvina, Vincent E; + view all
(2025)
First observations of continuum emission in dayside aurora.
Annales Geophysicae
, 43
(2)
pp. 349-367.
10.5194/angeo-43-349-2025.
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Abstract
We report the first observations of continuum emission at the poleward boundary of the dayside auroral oval. Spectral measurements of high-latitude continuum emissions resemble those of Strong Thermal Emission Velocity Enhancement (STEVE), with light characterized by colours such as white, pale pink, or mauve. The emission enhancement spans the entire visible wavelength range. However, unlike STEVE, the high-latitude dayside continuum emission events tightly follow the auroral particle precipitation, often forming field-aligned rays and other dynamic shapes. Some dayside emissions appeared as wide arcs or cloud-like structures within the red-emission-dominated dayside aurora. Our spectral measurements further suggest that the broadband continuum emission may extend into the near-infrared (NIR) regime. Similar to the STEVE emission, low-Earth-orbit measurements of plasma flow in the region of continuum emission show a strong horizontal cross-track velocity shear. Ground-based radar and optical observations provide evidence of both plasma and neutral heating, as well as upwelling, in connection to the continuum emissions. We conclude that the interplay between different heating mechanisms may be an important factor in generating high-latitude continuum emissions.
| Type: | Article |
|---|---|
| Title: | First observations of continuum emission in dayside aurora |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.5194/angeo-43-349-2025 |
| Publisher version: | https://doi.org/10.5194/angeo-43-349-202 |
| Language: | English |
| Additional information: | © Author(s) 2025. This work is distributed under the Creative Commons Attribution 4.0 License. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10211249 |
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