We got to see a treat this morning as the sun started to break through the fog around our communities. Watch carefully to see a fogbow or "white rainbow" form toward the middle of our camera view in Simpsonville.
Fogbows are made the same way rainbows are but with fog instead of rain. Instead of larger raindrops in the air, fog or low clouds are made of smaller water droplets. That difference is the reason rainbows have color, but fogbows are usually white. Because they are made the same way, fogbows are roughly the same size as rainbows and always form in the opposite direction of the sun. Watch for them in thin fog when the sun is bright, like what happened this morning. You need to have clear sun shining into the fog, so these fogbows occur normally as the fog is clearing in one area but remains locked another fog prone area.Â
If you notice, there is a bright arc within the fog that takes the shape of a rainbow. All clouds, including fog (clouds on the ground), are made up of water droplets. When the sun shines into these water droplets, the light is refracted like a prism as it moves through the water separating the colors of the near white light from the sun to the full spectrum of colors. This creates the colors, but doesn't really explain the actual bow. As the sunlight moves into the water droplet, some of the light bounces off the back of the droplet and back toward the person viewing it. This bouncing is what creates a single bow, but if the light bounces a second time off the back of the droplet before coming back to the person viewing it, then you get a double rainbow. Here is what it looks like:
