In search of the green flash

| 02/11/2016

What is a green flash and how common is it in Cayman?

Auntie’s answer: Let me start off by saying to anyone who thinks the green flash is a myth, the phenomenon is very real. I know it sounds like an old wives’ tale but it is an occurrence with a very scientific explanation behind it.

But nobody panic; I will condense the description down to the simplest terms I can and as I understand it. The green flash is an optical phenomenon that occurs at sunset, though it can be seen at sunrise as well. I am going to focus, as it were, on the sun-going-down discussion.

As the sun sinks to the horizon, the light is refracted by the atmosphere, which separates it, like a prism, into the colours of the visible spectrum (you know – red, orange, yellow, green, blue, indigo, violet, in order of longest to shortest wavelength). The shorter wavelengths are refracted most but the indigo, violet and blue get scattered more (please don’t ask me why), leaving green to be the colour of the flash.

I think that is all the technical stuff I have the energy to provide, so I am moving on to the second part of your question.

While I cannot say how common it is to spot a green flash here, the good news is that we in Cayman are in a great position to view it. One of the most important requirements is an uninterrupted view of the sunset, preferably over the sea (check). In addition, a clear sky free of pollution (check) and clouds (often enough) provides the best chance of the flash occurring.

Just wait till the sun is touching the horizon (if you look too long then it will affect your ability to see the green and it also is not good for your eyes). If the universe aligns for you, for a second or so there will be a flash of green at the top of the sun as it disappears.

Actually, I do have an old wives’ tale to relate. Apparently if you see a green flash, you will never make a mistake when it comes to matters of the heart. And that is as good a reason as any to keep looking for it.


Category: Ask Auntie

Comments (6)

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  1. .LONDONER says:


    • Beaumont Zodecloun says:

      educate us on how to post photos here, and I will surely do that very thing.

  2. Anonymous says:

    I have photographed a couple of green flashes. It helps if you are a few feet (5-10) above the horizon. Also seems to be more pronounced when there is a warm air layer over a cooler horizon.

    Look up “etruscan vase sunset”, and see what that phenomenon looks like. When I see sunsets such as those, the chances of seeing a green flash are improved.

  3. Satirony says:

    It can also be seen at sunrise. A few years ago at Ocean Club, when the air was super-clear, I rose early to mark exactly where the sun first appeared on the horizon at sunrise. The next morning, I was astonished to witness the brightest green flash I have ever seen. A friend of mine, by complete coincidence, witnessed the same event, and was equally astonished. It’s something I will never forget, having seen many ‘green flashes’ at sunset. These are more of a brief, green glow. I once watched the green flash through top-quality binoculars, and observed the green followed by indigo, then violet.

  4. Anonymous says:

    Seen it twice in Cayman in the past 12 years. Needs to be super clear atmosphere with no clouds on the horizon line at all.

    The film Le Rayon Vert by Eric Rohmer tells you pretty much all you need to know about the green flash and life. Yes, it is all true.

  5. Anonymous says:

    Interesting, thank you