Steve

STEVE ("Strong Thermal Emission Velocity Enhancement") is an atmospheric optical phenomenon that appears as a purple and green light ribbon in the sky, named in late 2016 by aurora watchers from Alberta, Canada. According to analysis of satellite data from the European Space Agency's Swarm mission, the phenomenon is caused by a wide ribbon of hot plasma at an altitude of , with a temperature of and flowing at a speed of (compared to outside the ribbon). The phenomenon is not rare, but had not been investigated and described scientifically prior to that time.