High temporal- and spatial-resolution photographs of the “Christmas” red-green auroras taken over Germany during a main phase of the 10–11 May 2024 superstorm

The 10–11 May 2024 superstorm had three main phase steps with peak intensities SYM-H=−183, −354 and −518 nT. During the second main phase red and green auroras occurred over Braunschweig and Göttingen, Germany. The Braunschweig and Göttingen red and green auroral images were taken during intense substorms within the storm second main phase. The high-altitude red aurora displayed brightness streaks/rays, which continued to lower-altitude green auroral brightness streaks/rays. Of the many postulated mechanisms for causing red auroras, it is concluded that high energy electron precipitation along the Earth's magnetic field lines was the main mechanism for both auroral streaks/rays. The plasmapause location estimated using the Dst index was L∼2.6, corresponding to the approximate L shell of Braunschweig and Göttingen.