Q. Which one of the following statements correctly defines the ‘Alpenglow phenomenon’, seen in the news recently?

[A] These are optical phenomena that create bright circles or arcs around the sun or moon.

[B] It is an optical phenomenon that appears as a horizontal reddish glow near the horizon opposite to the Sun when the solar disk is just below the horizon.

[C] These are beams of sunlight that appear to radiate from the point in the sky where the sun is located.

[D] It creates distorted and elongated images of distant objects, often appearing as castles or cities in the sky.

Answer: B
Notes:

Explanation – The Alpenglow phenomenon is an optical phenomenon that creates a horizontal reddish glow near the horizon opposite to the Sun when the solar disk is just below the horizon. It can occur during the twilight hours before sunrise or after sunset. Alpenglow occurs when direct sunlight around sunrise or sunset is reflected off airborne precipitation, ice crystals or particulates in the lower atmosphere, as the sunlight has no direct path to reach a mountain. In simple terms, the Alpenglow phenomenon is like a beautiful sunset or sunrise, but instead of coloring the sky, it paints the tops of mountains with a soft, reddish glow. Alpenglow specifically involves the reddish glow on mountain peaks during sunrise or sunset, while rainbows are multicolored arcs caused by the refraction and dispersion of sunlight by water droplets in the atmosphere.

Source: Forum IAS

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