Polarization in aurorae: A new dimension for space environments studies

• Published in: Geophysical Research Letters
• Main Authors: Lilensten, Jean, Moen, Joran, Barthelemy, Mathieu, Thissen, Roland, Simon, Cyril, Lorentzen, D. A., Dutuit, Odile, Amblard, Pierre-Olivier, Sigernes, Fred
• Other Authors: Laboratoire de Planétologie de Grenoble (LPG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics Oslo, Faculty of Mathematics and Natural Sciences Oslo, University of Oslo (UiO)-University of Oslo (UiO), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Arctic Geophysics Research, The University Centre in Svalbard (UNIS), GIPSA - Signal Images Physique (GIPSA-SIGMAPHY), Département Images et Signal (GIPSA-DIS), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: [SDU]Sciences of the Universe [physics]; Svalbard
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00363722; https://hal-insu.archives-ouvertes.fr/insu-00363722/document; https://hal-insu.archives-ouvertes.fr/insu-00363722/file/2007GL033006.pdf; https://doi.org/10.1029/2007GL033006

International audience The polarization of emission lines is a noteworthy observational parameter in astronomy. However, it has never been detected without ambiguity in planetary upper atmospheres. Theoretical considerations have suggested that the polarization of the thermospheric oxygen red line (630 nm) could exist in the polar cap region. We present here its first successful measurement at Svalbard in January 2007, during active geophysical conditions. We assign its origin and variability to complementary effects between permanent low-energy electron precipitation and sporadic auroral events. Implications in physics, geophysics and planetary science are foreseen. In physics, it raises the question of the polarization of a forbidden transition by electron impact which is still unknown. In geophysics, it provides a new parameter to constrain the thermospheric models. In planetary science, it makes it possible to derive the local configuration of the magnetic fields. It therefore opens new perspectives for future space missions towards other planets.