Ballooning-Interchange waves and heads: https://www.nasa.gov/feature/aurora-mysteries-unlocked-with-nasa-s-themis-mission/ Magnetospheric buoyancy waves: https://www.nasa.gov/feature/goddard/2016/nasa-s-themis-sees-auroras-move-to-the-rhythm-of-earth-s-magnetic-field/ https://science.nasa.gov/science-news/science-at-nasa/2010/27jul_spacequakes