Whenever my husband and I watch the sun go down over a large body of water we ask each other if we will see the green flash. If we are in the company of others, they often look at us as if we are crazy or pulling their legs. During our most recent visit to the beach on the Gulf of Mexico we witnessed the green flash two nights in a row. Since we can go years without seeing the flash, this was quite an unusual occurrence. The flash is a brief burst of extraordinary green color as the sun descends below the horizon. If you blink at the wrong time you will miss it. Yes, there is a scientific explanation for the green flash or the green ray.
Atmospheric conditions have to be just right in order for the green flash to occur. Although the phenomenon can be observed at varying altitudes, including from a plane, it is most often seen at sunset on the horizon over a large body of water. The flash is due to the refraction of light in the atmosphere similar to the light refraction of a prism. The air closer to the earth is denser than the air above. Light moves slower through the dense air than the thinner air above. Sunlight rays follow paths that curve in the same direction as the earth curves. Green and blue colors are high frequency light rays that curve more than the lower frequency red and orange rays. Therefore the green/blue rays of the setting sun remain visible a bit longer than the red/orange rays. Sunset on a clear day provides the best opportunity to see the green flash because more of the light reaches the viewer without being scattered.
According to the Wikipedia website, there are several mentions of the green flash or green ray in literature and film. Jules Verne wrote a novel called “The Green Ray” in 1882 in which he describes the green color as almost supernatural. In 1986 the French came out with a film entitled “The Green Ray” or “Le Rayon Vert.” The writers of the 2007 film “Pirates of the Caribbean: At World’s End” included the green flash as part of the plot. J.R.R. Tolkein wrote about the green flash in “The Hobbit.” In her novel, “The Pride and the Peacock,” Victoria Holt also describes a green flash.
The next time you have the opportunity to watch the sun setting over the water on a clear day, watch carefully and you may see the green flash. Hold your breath and remember not to blink as the sun slowly sinks into the water. Even if you do not see the green flash, the experience is well worth the wait.