What are those red lights in the sky?

Source: FOX19 Viewer Lori Ortlieb, Fayetteville, OH
Source: FOX19 Viewer Lori Ortlieb, Fayetteville, OH

(FOX19) - Just what are those red lights in the sky? Chief Meteorologist Steve Horstmeyer has the answer.

On a dark clear night, when our viewers see lights in the sky it is one of two phenomena. First and most often, it could be very high, thin clouds reflecting sunlight. Even though the sun set an hour or more earlier high in the atmosphere the sun is still above the horizon. The light in this case is usually pale white but it can be pale red if there is dust in the atmosphere to the west.

Occasionally we see the northern lights here in Cincinnati. Scientists call this phenomenon the aurora borealis and when charged particles from the sun interact with Earth's magnetic field a variety of colors and shapes can result.

Red usually signifies oxygen atoms in the very highest part of the atmosphere, above 120 miles up, interacting with the charged particles of the solar wind. Green (sometimes yellowish-green) too is oxygen and blue is nitrogen but at a lower elevation between 60 and 120 miles up. The blue nitrogen glow is hard to see against the black sky so it is rarely reported. A bit lower still, below 60 miles up, nitrogen glows deep red/crimson color.

The northern lights produce their glow the same way neon lights work. A gas is subject to an electrical charge. The charge strips electrons from the atoms of the gas and when the electron flow they collide with the atoms of the gas and the excited gas emits light.

Monday evening the auroral oval extended south of the Ohio River and the index that classifies geomagnetic storms reached 6 indicating a small geomagnetic storm.