New Science in Plain Sight : Citizen Scientists Lead to Discovery of Optical Structure in the Upper Atmosphere

MacDonald, Elizabeth and Donovan, E. and Nishimura, Y. and Case, Nathan Anthony and Gillies, D. M. and Gallardo-Lacourt, B. and Archer, W. E. and Spanswick, E. and Bourassa, N. and Connors, M. and Heavner, Matt and Jackel, B. and Kosar, Burcu and Knudsen, D. J. and Ratzlaff, C. and Schofield, I. (2018) New Science in Plain Sight : Citizen Scientists Lead to Discovery of Optical Structure in the Upper Atmosphere. Science Advances, 4 (3): eaaq0030. ISSN 2375-2548

PDF (aaq0030_ArticleContent_v4)
aaq0030_ArticleContent_v4.pdf - Accepted Version
Restricted to Repository staff only until 1 January 2050.
Available under License Creative Commons Attribution-NonCommercial.
Download (431kB)

Preview

PDF (eaaq0030.full)
eaaq0030.full.pdf - Published Version
Available under License Creative Commons Attribution-NonCommercial.
Download (645kB)

Abstract

A glowing ribbon of purple light running east-west in the night sky has recently been observed by citizen scientists. This narrow, subauroral, visible structure, distinct from the traditional auroral oval, was largely undocumented in the scientific literature and little was known about its formation. Amateur photo sequences showed colors distinctly different from common types of aurora and occasionally indicated magnetic field–aligned substructures. Observations from the Swarm satellite as it crossed the arc have revealed an unusual level of electron temperature enhancement and density depletion, along with a strong westward ion flow, indicating that a pronounced subauroral ion drift (SAID) is associated with this structure. These early results suggest the arc is an optical manifestation of SAID, presenting new opportunities for investigation of the dynamic SAID signatures from the ground. On the basis of the measured ion properties and original citizen science name, we propose to identify this arc as a Strong Thermal Emission Velocity Enhancement (STEVE).