Photos

This is a shot I took in Dominica showing the 'Green Flash' sometimes given off by the setting sun. I've seen the green flash 3 times on different visits to Dominica and managed to get this image on my last visit there in 2006. It's a fantastic phenomenon to witness.

I have only recently discovered that it is a rare occurrence so I feel very lucky and privileged to have seen and even captured an image showing it!

This from Wikipedia -
Green flashes and green rays are rare optical phenomena that occur shortly after sunset or before sunrise, when a green spot is visible for a short period of time above the sun, or a green ray shoots up from the sunset point. It is usually observed from a low altitude where there is an unobstructed view of the horizon, such as on the ocean.

Its explanation lies in refraction of light (as in a prism) in the atmosphere and is enhanced by atmospheric inversions. Whilst we would expect to see a blue light, the blue is dispersed (this is why the sky is blue) and only the green light remains visible.

With slight magnification a green rim on the top limb of the solar disk can be seen on most clear-day sunsets. However the flash or ray effects require a stronger layering of the atmosphere and a mirage which serves to magnify the green for a fraction of a second to a couple of seconds.