Send to

Choose Destination
Sci Adv. 2018 Mar 14;4(3):eaaq0030. doi: 10.1126/sciadv.aaq0030. eCollection 2018 Mar.

New science in plain sight: Citizen scientists lead to the discovery of optical structure in the upper atmosphere.

Author information

NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
New Mexico Consortium, Los Alamos, NM 87544, USA.
University of Calgary, Calgary, Alberta, Canada.
Boston University, Boston, MA 02215, USA.
University of California, Los Angeles, Los Angeles, CA 90095, USA.
Lancaster University, Lancaster, UK.
Alberta Aurora Chasers, Alberta, Canada.
Athabasca University, Athabasca, Alberta, Canada.
Department of Physics and Astronomy and Centre for Planetary Science and Exploration, Western University, London, Ontario N6A 3K7, Canada.
Los Alamos National Laboratory, Los Alamos, NM 87545, USA.


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).

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center