dayglow

noun

1. See under airglow.

noun

1. a dim light from the upper atmosphere caused by emissions from atoms and molecules ionized by solar radiation: observed at night (nightglow), during the day (dayglow), and at twilight (twilight glow), with each having slightly different characteristics.

noun

1. the faint light from the upper atmosphere in the night sky, esp in low latitudes

1. A faint photochemical luminescence in the upper atmosphere caused by the collision of x-rays and charged particles from the Sun with atoms and molecules, especially of oxygen, sodium, and the hydroxyl radical (OH). Airglow is strongest over low and middle latitudes.