[en] Discrete aurora are sporadic emissions of light originating in Mars upper atmosphere.
We report nadir imaging observations from MAVEN’s Imaging UltraViolet Spectrograph which identify the conditions which trigger electron precipitation causing these events. Prior studies have shown that discrete aurora events in the strong crustal magnetic field region in the southern hemisphere are the brightest and most repeatable compared to events occurring outside the region. Our new dataset offers a more complete and accurate characterization of aurora in this area. The region of strongest crustal fields is composed of two distinct magnetic regions, with magnetic fields in opposite directions; discrete aurora trigger in one region after dusk and in the other before dawn. Magnetic reconnection in these two adjacent regions with the draped interplanetary field may open the crustal fields in these regions during opposing local times.
Particles precipitation can then cause discrete aurora at the observed times and locations.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Johnston, Benjamin
Schneider, Nicholas
Jain, Sonal
Milby, Zachariah
Deighan, Justin
Bowers, Charles
DiBraccio, Gina
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Soret, Lauriane ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP) ; Université de Liège - ULiège > Unités de recherche interfacultaires > Space sciences, Technologies and Astrophysics Research (STAR)
