Green Flash

When I was growing up in Nebraska, I sometimes saw the fabled 'green flash' at sunrise. When I moved away, I missed it and sought to find it again. I rarely wake up early enough to see it during sunrise over the Atlantic, so I am most likely to see the green flash when I return to Nebraska or visit the West Coast or Hawaii.

What is the green flash? It's a spot or beam of vivid green light that you can see at the top of the sun as it rises or sets. You can only see it if the conditions are just right, so it's a rare treat.

Photo: Green Flash in San Francisco (Mila Zinkova)

The green flash is an optical phenomenon in which a spot or ray of green is seen at the top of the rising or setting sun. The green flash is most commonly seen over a flat horizon such as a plain or the sea, but it can be seen at any altitude and over cloud tops and mountaintops as well.

The green flash results from the refraction of light in the earth's atmosphere. Higher frequency green light curves more than lower frequency light red and orange light, so green rays from the sun can be seen even after the orange and red rays are blocked by the earth's curvature. Sometimes even blue rays can be seen, though this is even more rare.

Photo: Green Flash, San Francisco (Mila Zinkova)

It's a lot easier to capture the green flash on your camera than it is to see it with your eyes as the sun rises or sets! If you can, it's best to make a movie so that you don't miss the flash. Many cell phones have this capability and so do most digital cameras, so you don't have to use a camcorder unless you have one handy.

If you are lucky, you can capture the green flash on most days when it is clear or there are just a few clouds near the sun. If there is a thermal inversion, your chances of seeing the flash are even better. Basically this means you have a great chance of seeing the flash over the ocean or in a city with smog.

Start taking pictures or making your video a few minutes before the sun sinks below the horizon. Even if you do not see the green flash, your camera might, so review your pictures.

Have you seen the green flash or would you like to? Feel free to sign my guestbook and tell me what you think of the green flash or this lens.