The green flash is a rare optical phenomenon that occurs just as the sun sets or rises. It happens when the atmosphere separates or refracts different colors of sunlight. Blue and violet light are scattered away, while green light can briefly reach our eyes for a second or two.
This effect is most likely to be seen when:
- The horizon is clear and unobstructed (often over water)
- The air is very clear with minimal pollution
- The viewer is at a higher elevation
- Atmospheric conditions are stable
While commonly described as a flash, it can also appear as a small green dot or rim on the upper edge of the sun. Photographers often capture this phenomenon more easily than the naked eye can detect it.