First observations of continuum emission in dayside aurora
Year: 2025
Type: article
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.
Source: Annales Geophysicae
Authors: Noora Partamies, Rowan Dayton-Oxland, Katie Herlingshaw, Ilkka Virtanen, Bea Gallardo-Lacourt, Mikko Syrjäsuo, Fred Sigernes, Takanori Nishiyama, Toshi Nishimura, Mathieu Barthelemy, Anasuya Aruliah, Daniel Whiter, Lena Mielke, Maxime Grandin, Eero Karvinen, Marjan Spijkers, Vincent E. Ledvina
Institutions: University Centre in Svalbard, University of Southampton, University of Oulu, Goddard Space Flight Center, Catholic University of America, National Institute of Polar Research, Boston University, Centre National de la Recherche Scientifique, Institut de Planétologie et d'Astrophysique de Grenoble, Université Grenoble Alpes, University College London, Finnish Meteorological Institute, University of Alaska Fairbanks
Language: English
Subfield: Space and Planetary Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,186
Awards: G2969202172, Auroral, Energetic and Relativistic particle precipitation: Global Energy input and Local Chemical effects in the High-latitude atmosphere (AERGELC'H), INSPIRE: Interdisciplinary Southampton Partnership for Investigators Researching the Environment, Aurora and Neutral Atmosphere interplay: Observations and Novel analysis methods (ANAON), How does the aurora heat the upper atmosphere?
OpenAlex ID: W4411976007