SARarc and STEVE

These two phenomenas are no auroral instances. It is known that there is some relation to the solar wind but the exact connection to that is yet unknown.

SARarc stands for Stable Auroral Red arc. It looks like an aurora but it stays almost fixed with only slight movements and has a deep red colour. SARarcs can move on to transition into a STEVE.

STEVE stands for Strong Thermal Emission Velocity Enhancement.

Both phenomenas seem very likely to be connected and appear only in subauroral lattitudes. They have been spotted between the lattitudes of Italy and New Zealand.

Citation from a comprehensive article on the SARarc and STEVE:
"These phenomena are distinct from auroras, as their optical signatures appear to be triggered by extreme thermal and kinetic energy in Earth's atmosphere, rather than produced by energetic particles raining down into our atmosphere," the researchers wrote in the new study. Satellite observations of the event suggest that the night's geomagnetic storm may have played a key role in this parade of sky lights."