Context:
NASA recently shared an incredible picture of an aurora captured from the International Space Station.
Relevance:
GS I: Geography
Dimensions of the Article:
- Formation of Auroras
- Carbon Dioxide Aurora
Formation of Auroras:
- Auroras are formed when charged particles ejected from the sun’s corona create solar wind, which interacts with Earth’s ionosphere.
- In the Northern Hemisphere, they are called the northern lights or aurora borealis, while in the Southern Hemisphere, they are known as the southern lights or aurora australis.
- The asymmetry of auroras between hemispheres is influenced by the interference between the sun’s magnetic field and Earth’s magnetic field.
- The commonly observed green and red auroras occur between 100 to 250 kilometers above the planet’s surface due to the excited state of atomic oxygen.
Carbon Dioxide Aurora:
- When charged particles collide with Earth’s atmosphere, they interact with various atoms and molecules, including carbon dioxide.
- Carbon dioxide, known for its role as a greenhouse gas in the lower atmosphere, also exists in trace amounts in the upper atmosphere.
- Around 90 kilometers above Earth, carbon dioxide molecules become excited during an aurora, leading to the emission of infrared radiation.
- This results in a higher presence of infrared radiation in the atmosphere compared to typical levels.
-Source: Indian express
