What causes a green flash? Green flashes are enhanced by mirage, which increase refraction. A green flash is more likely to be seen in stable, clear air, when more of the light from the setting sun reaches the observer without being scattered. One might expect to see a blue flash, since blue light is refracted most of all, and the blue component of the suns light is therefore the very last to disappear below the horizon, but the blue is preferentially scattered out of the line of sight, and the remaining light ends up appearing green. With slight magnification a green rim on the top of the solar disk may be seen on most clear-day sunsets, although the flash or ray effects require a stronger layering of the atmosphere and a mirage, which serves to magnify the green from a fraction of a second to a couple of seconds.
Posted on: Thu, 31 Jul 2014 01:17:43 +0000
Trending Topics
Recently Viewed Topics
© 2015