STEVE is an atmospheric optical phenomenon that appears as a purple and green light ribbon in the night sky, named in late 2016 by aurora watchers from Alberta, Canada.

[1] One of the aurora watchers, photographer Chris Ratzlaff,[9][10] suggested using the name "Steve" for the phenomenon, in reference to Over the Hedge, an animated comedy movie from 2006.

[12][13] During the fall meeting of the American Geophysical Union in December 2016, Robert Lysak suggested using a backronym of "Steve" for the phenomenon that would stand for a "Strong Thermal Emission Velocity Enhancement".

[15] STEVE phenomena may be spotted further from the poles than the aurora,[16] and as of March 2018, have been observed in the United Kingdom, Canada, Alaska, northern U.S. states, Australia, New Zealand[17] and Denmark.

[20] A study published in March 2018 by Elizabeth A. MacDonald and co-authors in the peer-reviewed journal, Science Advances, suggested that the STEVE phenomenon accompanies a subauroral ion drift (SAID),[21] a fast-moving stream of extremely hot particles.

Hence, the green bars in the picket fence are moving more slowly than the structures in the purple emissions and some scientists have speculated they could be caused by turbulence in the charged particles from space.