How to Spot a Green Flash Sunset: Ideal Conditions and Safety Guide
By Alexander Ross
The green flash is fundamentally a product of atmospheric refraction. Earth’s atmosphere functions like a gigantic, curved lens. Air density increases closer to the ground or sea surface, causing incoming light rays from the sun to bend downward. Because shorter wavelengths bend more sharply than longer wavelengths, light dispersion separates the descending sun into stacked color layers. Red light bends the least, followed by orange, yellow, green, and blue.
As the sun sets, the red and orange disks drop below astronomical horizon lines first. Under normal circumstances, blue and violet light should linger longest. Earth's atmosphere scatters blue and violet photons across wide angles through Rayleigh scattering, which explains why the midday sky appears blue and sunrises look red. By the time twilight arrives, air particles have filtered out nearly all violet and blue light.
Green remains the last surviving high-refraction wavelength. When the upper rim of the sun hits the ocean edge, the green light briefly emerges isolated from the rest of the solar spectrum. The entire burst routinely clocks in at between 1.2 and 2.1 seconds, demanding total focus from ground observers.
Alexander Ross has covered the video game industry for a decade, writing deep dives on game design, esports tournaments, VR developments, and gaming culture.
