Fig. 5: Schematic diagram of electron precipitation driven by LBC and SH.
From: Diffuse auroral precipitation driven by lower-band chorus second harmonics
After injected from magnetotail (step 1), fresh electrons become anisotropic to excite lower-band chorus (LBC, step 2). Lower-band chorus can self-consistently generate their second harmonic (SH) emissions (step 3, observed by the Van Allen Probe mission, VAP), and then they work together (step 4) to cause electron precipitations both above and below 4 keV to form diffuse aurora (step 5, observed by the National Oceanic and Atmospheric Administration Polar Orbiting Environmental Satellite, NOAA). Balls with bright red colors denote electrons with energies >4 keV while those with dark red colors are below 4 keV.
