Description:
The correct answer is:
✅ Refraction and reflection of light
Why?
Halos around the Sun or Moon are caused by ice crystals in high-altitude cirrus clouds:
Refraction: Light bends passing through hexagonal ice crystals, creating a 22° halo (most common).
Reflection: Some halos form when light bounces off crystal surfaces (e.g., sundogs).
Key Features:
Colors: Often faintly rainbow-like (red inside, blue outside).
Weather Sign: Often signal approaching warm fronts (and rain/snow within 24–48 hours).
Why Not the Others?
❌ Solar flares: Affect space weather, not atmospheric optics.
❌ Magnetic fields: Influence auroras, not halos.
Fun Fact: The same ice crystals cause sun dogs, light pillars, and circumzenithal arcs! 🌞❄️
Spot a halo? Rain might be coming! 🌧️☁️