Fig. 2: Images recorded on 21 September 2019 at 19:45:14 UTC.
From: Spectroscopy of a mesospheric ghost reveals iron emissions
a Composite image of the jellyfish sprite (red). The slit projection is superimposed as a yellow line. Time-lapse video was taken with a monochrome Teledyne FLIR Grasshopper3 video camera (Sony IMX174 CMOS sensor) fitted with a 25 mm F0.95 lens and a 720 nm infrared long-pass filter. The exposure time of each frame was 1 s. The composite has been made using the sprite event frame as red RGB channel, the airglow image as the green channel, while the blue channel is a frame of a cirrus cloud revealed by the reflection of light from a distant lightning flash 13 s after the event. b Averaged (stacked) video frames of airglow background in the 10 s before and after the sprite time show some banded structure which we interpret as likely caused by modulation of the hydroxyl (OH*) airglow layer by gravity waves.
