Intro – Definition:
- Aurora Borealis: Also called Northern Lights, visible in high-latitude regions near the North Pole.
- Aurora Australis: Known as Southern Lights, seen near the South Pole.
Formation Mechanism:
- Solar Wind Emission:
- Sun emits charged particles (electrons, protons) during solar flares/CMEs.
- Earth’s Magnetic Field Interaction:
- Particles are directed by Earth’s magnetosphere toward the polar regions.
- Atmospheric Collision:
- Charged particles collide with oxygen and nitrogen molecules in the upper atmosphere (80–300 km altitude).
- Excitation and de-excitation release visible light.
- Resulting Colors:
- Green: Oxygen at ~100 km.
- Red: Oxygen at ~200+ km.
- Blue/Violet: Nitrogen at lower altitudes.
Conditions for Visibility:
- High solar activity.
- Clear, dark skies near magnetic poles (Arctic, Antarctic circles).
Significance:
- Indicators of solar-magnetic interactions.
- Affect satellite communication and GPS.
- Studied in space weather research.
Conclusion:
- Auroras are natural luminous phenomena caused by solar wind interactions with Earth’s magnetosphere, visually representing space-Earth electromagnetic dynamics.
