As seen across North America at sometimes surprisingly low latitudes, brilliant auroral displays provide evidence of solar activity in the night sky. More is going on than the familiar visible light shows during these events, though: When aurora appear, the Earth’s ionosphere is experiencing an increase in ionization and total electron content (TEC) due to energetic electrons and ions precipitating into the ionosphere.One extreme auroral event earlier this year (May 10–11) was the Gannon geomagnetic “superstorm,” named in honor of researcher Jennifer Gannon, who suddenly passed away May 2. During the…
