Emerald sunset

An emerald sunset is a green flash that appears just before the setting of the sun and is caused by the interaction of light with the earth's atmosphere. The processes involved in creating a green flash are non-trivial to explain, but have to do with the scattering of light by the particles in the upper atmosphere, and the fact that the light emitted by the Sun peaks in the green wavelengths.

These "green flashes" at sunset occur when viewing a distant sunset over very flat land or over the water from a high mountain. They have usually never been seen by most but have been seen esp. by sailors.

External links

• http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/redsun.html
• http://www.factmonster.com/ce6/sci/A0930510.html