Optical Phenomenon or Mythological Romanticism?

If you've spent time near the coast or on the water, you've likely heard about the optical phenomenon known as a "green flash" or "emerald flash". It is said to be witnessed just as the sun sinks below the horizon and is only visible for a brief moment. Here in Southwest Florida the green flash is common folklore (or is it lore?), even hosting a beachside restaurant with the same name.

The phenomenon is widely believed to be a Scottish legend. It is said that, "He who has been fortunate enough once to behold it is enabled to see closely into his own heart and to read the thoughts of others." The problem with the Scottish legend theory is that it was derived from Jules Verne's 1882 novel, Le Rayon-Vert. Verne describes the green flash as, "A green ray, but of a marvelous green, a green which no painter could ever obtain on his palette, a green of which nature, neither in the varied tints of vegetation nor in the shades of the most limpid seas could ever produce the like! If there is a green in paradise, it cannot be but of this shade, which most surely is the true green of Hope." Such legend is clearly derived more from French romanticism than Scotch whisky.

An old English proverb states, "Glimpse you ere the green ray, count the morrow a fine day." But I've witnessed a "red sky at night" followed by torrential rain upon many occasions. According to Pirates of the Caribbean, a green flash signifies a return of the soul from the land of the dead. Less romantic than Verne perhaps, yet seemingly a Hollywood conception.

There are many incorrect theories pertaining to green flashes. They are not a result of latitudinal restriction or sun shining through water as they can theoretically be witnessed anywhere. They are not an after-image as they can also be witnessed at sunrise. They have little dependence on the upper atmosphere and more reliance towards the layer of atmosphere between the astronomical horizon and apparent horizon. They are also not a result of air path length however, it does explain why flashes are most commonly seen as green rather than blue or violet.

So what is the cause of a green flash? It's quite simple really. They are an actual phenomenon supported by scientific data and not an illusion. They are mirages enhanced by astronomical refraction nearing optical infinity, which differs from terrestrial mirages. However, without mastering colorimetry, angular measurements, atmospheric refraction, molecular scattering, temperature gradients, and other such factors, I am unable to relay exactly why, where, when, and which distinctive type of green flash one may or may not witness.

I've had the pleasure of observing sunrises and sunsets from Pacific and Caribbean islands, high deserts and low deserts, mountains, hollows, lakes, rivers, and frequent sunsets at the local Gulf beach. I've witnessed solar eclipses, lunar eclipses, comets, and meteor showers, yet I still have not seen a green flash. That doesn't necessarily mean I'm denying the existence of the phenomenon. I've also never seen a jackelope or a skunk ape. What I do know however, is if you listen very carefully from the beach, you can hear the sun extinguish as it sinks into the ocean. Pssssssssssst...