Aurora Borealis is formed in which region of Earth's atmosphere?

Aurora Borealis is formed in which region of Earth's atmosphere?

• A. Ionosphere
• B. Troposphere
• C. Stratosphere
• D. Exosphere

Answer: (A)

Charged particles from the solar wind are funneled along Earth’s magnetic field into the polar upper atmosphere, where they collide with gas molecules. These collisions excite the atoms and ions, and as they return to lower energy states, they emit light, creating the aurora. This glow occurs in the upper atmosphere within the ionosphere, at altitudes of roughly 80 to a few hundred kilometers. The lower layers (troposphere and stratosphere) are too deep and dense, and the outer exosphere is too diffuse to produce this effect.

Charged particles from the solar wind are funneled along Earth’s magnetic field into the polar upper atmosphere, where they collide with gas molecules. These collisions excite the atoms and ions, and as they return to lower energy states, they emit light, creating the aurora. This glow occurs in the upper atmosphere within the ionosphere, at altitudes of roughly 80 to a few hundred kilometers. The lower layers (troposphere and stratosphere) are too deep and dense, and the outer exosphere is too diffuse to produce this effect.