Context:
Recently, a rare celestial phenomenon known as a “double sun halo” was witnessed in the skies over Ladakh.
Relevance:
Facts for Prelims
Understanding the Double Sun Halo
Definition:
- The double sun halo is a rare optical phenomenon featuring two concentric rings surrounding the sun.
Formation:
- This occurs when sunlight is refracted through ice crystals suspended in cirrus clouds, resulting in a dazzling visual effect.
- The double sun halo is a variant of the common 22-degree halo, which is a bright ring that encircles the sun.
- In the case of the double sun halo, there are two distinct halos: an inner halo with a radius of approximately 22 degrees and an outer halo with a radius of around 46 degrees from the sun’s center.
Mechanism:
- The formation of a double sun halo is due to the unique shape and orientation of ice crystals in cirrus clouds.
- These crystals, typically hexagonal, act as natural prisms, refracting and reflecting sunlight at specific angles.
- When the ice crystals are randomly oriented, the refracted sunlight creates the inner 22-degree halo.
- If the crystals align horizontally, with their flat faces parallel to the ground, additional refraction occurs, forming the outer 46-degree halo.
- The precise alignment of these ice crystals is rare, making the double sun halo an uncommon sight.
Occurrence:
- This phenomenon is especially visible in regions with ideal atmospheric conditions, such as Ladakh.
Significance:
- The double sun halo is not only a stunning natural spectacle but also an indicator of specific atmospheric conditions involving ice crystal orientation and sunlight refraction.
-Source: India Today
