Green Flash at Sunrise

Imaged by a telephoto lens, the sun rises over one of the Dokdo islets (also known as Liancourt Rocks) off the coast of Korea. The image shows a little green light at the top of the solar disc. Difficult to observe, the momentary green flash above the rising or setting sun has been documented as a phenomenon caused by the atmospheric bending or refraction of sunlight. Like a weak prism, the Earth’s atmosphere breaks white sunlight into colors, bending red colors slightly and green and blue colors through increasingly larger angles. When the sky is clear, a green rim just above the sun’s edge can sometimes be seen for a second or so, when the sun is close to a distant horizon.