Bizarre Green Flash at Topmost Part of Rising, Setting Sun Explained

Have you noticed a green light during sunrise or sunset? If you do and wonder what it is, this article will explain the phenomenon called "green flash."

Green Flash at Sunrise and Sunset

In very rare circumstances, when the sky is exceptionally bright and translucent, a green flash may be seen just as the sun's very top portion is rising or setting, Space.com reported.

Earth's atmosphere separates the stack of different-colored images when the sun is close to the eastern or western horizon, mimicking the behavior of subpar optics. In particular, short wavelengths in the green and blue images are scattered by the air.

The red and orange hues observed at sunrise and sunset are produced by the long wavelengths of the red and orange pictures, which are more penetrating. But under extremely rare circumstances, when the sky is exceptionally clear and translucent, a tiny portion of the green image can be seen just as the sun's topmost point rises or sets. The green color is caused by atmospheric refraction of light, which makes things near the horizon look slightly higher in the sky than they are. This very uncommon phenomenon is known as the "green flash."

The green flash is an optical phenomenon that you can observe immediately following or just before sunrise or sunset, according to Earth Sky. It occurs when only the sun's upper edge, almost completely below the horizon, is still visible. That upper rim of the sun will appear green for a brief moment. The fabled "green flash" is a fleeting flash of green.

The sun's blue light is raised slightly more than its red light because refraction is stronger for green and blue light than for yellow and red light. Similar to the effect of seeing the moon via improperly aligned optical instruments, this mild prismatic effect of the atmosphere causes a bluish or greenish fringe on the upper border of the sun.

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How to See a Green Flash?

There are two requirements to witness this phenomenon. First, it should be a clear day. By this, we mean no haze or cloud on the horizon. Second, you need a distant horizon and a distinct edge to the horizon.

You will only see the green flash from a mountain top or high building. It is mostly observed over the ocean by individuals on beaches or in boats.

To avoid damaging your eyes, wait until the sun is almost below the horizon before looking at it. Otherwise, you will ruin your chances of seeing a green flash that day.

Green flashes are most frequently observed after sunset since you need to know exactly where to look along the horizon and because most people aren't awake at dawn. However, alert watchers can also spot them before sunrise.

Green flashes can also be seen over land if your horizon is far enough away. But they are most frequently observed over the ocean.