Q. If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth?
- GPS and navigation systems could fail.
- Tsunamis could occur at equatorial regions.
- Power grids could be damaged.
- Intense auroras could occur over much of the Earth.
- Forest fires could take place over much of the planet.
- Orbits of the satellites could be disturbed.
- Shortwave radio communication of the aircraft flying over polar regions could be interrupted.
Select the correct answer using the code given below: (UPSC Prelims 2022)
Answer:
1, 3, 4, 6 and 7 only
Notes: The correct answer is
[C] 1, 3, 4, 6 and 7 only. Solar storms, or Coronal Mass Ejections (CMEs), primarily affect the Earth's magnetic field and atmosphere, impacting electronic and electrical systems.
- GPS and Navigation (Statement 1 – Correct): Solar flares ionize the ionosphere, causing signal delays and inaccuracies in GPS and satellite navigation.
- Power Grids (Statement 3 – Correct): Solar storms induce Geomagnetically Induced Currents (GICs) in power lines, which can overheat and damage high-voltage transformers, potentially causing widespread blackouts.
- Intense Auroras (Statement 4 – Correct): When charged particles from the sun collide with Earth's atmosphere, they create spectacular auroras (Northern and Southern Lights). Major storms can push these displays toward much lower latitudes than usual.
- Satellite Orbits (Statement 6 – Correct): Solar activity heats the upper atmosphere, causing it to expand. This increased atmospheric density creates extra drag on low-Earth orbit satellites, causing them to slow down and drop in altitude.
- Shortwave Radio (Statement 7 – Correct): High-frequency (shortwave) radio relies on the ionosphere for reflection. During solar storms, the absorption of radio waves increases, leading to "radio blackouts," particularly on polar routes.
- Tsunamis (Statement 2 – Incorrect): Tsunamis are geological events caused by underwater earthquakes, volcanic eruptions, or landslides. Solar storms do not have the physical mechanism to trigger tsunamis.
- Forest Fires (Statement 5 – Incorrect): While solar flares involve high energy, they do not cause direct ignition of forests on Earth's surface. The Earth's atmosphere and magnetic field shield the surface from direct thermal combustion from such flares.