Side-by-side images show fish-eye-style photographs of a starry evening sky illuminated by different subauroral events. The left image shows a SAR arc, a reddish arc that spans the sky. Beneath the arc the sky transitions from bright green at the horizon to purple and is partially obscured by clouds. The right image shows a STEVE phenomenon. Part of the red SAR arc is still visible but is much fainter and more of a pink color than its original red. The green and purple sky is more muted in color, and more stars and the band of the Milky Way are now visible. In both images, the silhouette of some shrubs is visible.

From SAR Arc to STEVE: An Atmospheric Evolution

A new study reports the first observation of a stable auroral red arc evolving into a strong thermal emission velocity enhancement during a geomagnetic storm.

Eos
0 Comments