SIOUX FALLS, S.D. (KELO) — On hot days like this, the weather likes to play a trick on us and make us think that there’s something in the distance we desperately need.
The weather, and specifically the sun, is capable of producing some interesting optical phenomena from sun dogs firing on the horizon to rainbows above. Lately, you may have seen one just as you drive along the road. In the distance, it may look like there’s standing water on the road. In actuality, you’re seeing one form of a mirage.
There are three main kinds of mirages: Inferior mirage, superior mirage, and Fata Morgana. What you see on the road is an inferior mirage, which is a false image that forms under the actual object due to the refraction of light. In this case, the object in question is the sky.
This refraction of light is due to a temperature gradient near the surface. Though the air outside is already hot, it’s still cooler than the air immediately above even hotter pavement. As a result, and due to the different densities of each layer of air, light is bent upward…giving us the illusion that there is water on the ground when it’s actually light from the sky.
Even though mirages like this are usually associated with summer, inferior mirages can occur at any point during the year…even in the winter.