Good times – really bad summer weather in Switzerland brought me “back home” to Islamorada. Enjoy some sun and outside swimming that’s exactly what I needed to start my winter season. Another good reason for me to come back of course is that I still need to catch the Green flash.
Green flashes 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 (so Islamorada in the Florida Keys should be a perfect place to catch it). Its explanation lies in refraction of light 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. And I was told that it is a good thing to see the green flash. Can’t say if it’s true or not, but I really would love to see a Green flash once.