AAPOD2 Image Archives
Milky Way and STEVE
STEVE, or Strong Thermal Emission Velocity Enhancement, is a fascinating atmospheric phenomenon distinct from typical auroras. Unlike the common green and red hues of auroras caused by charged particles from the solar wind interacting with Earth's magnetic field, STEVE appears as a purplish arc with "picket fence" structures of green light. This phenomenon has intrigued scientists and citizen scientists alike, leading to its formal identification and study in recent years.
STEVE occurs at lower latitudes compared to traditional auroras and is associated with high-speed streams in the upper atmosphere. The exact mechanisms behind STEVE are still under investigation, but it is believed to involve different physical processes, possibly related to ionospheric heating and particle precipitation. Observations of STEVE, often captured by amateur photographers and skywatchers, provide valuable data that help scientists better understand the complex interactions between solar activity and Earth's magnetosphere.