Published on 31 Jan 2025
South Atlantic anomaly is a region at the Earth’s surface where the intensity of the magnetic field is particularly low. It stretches out between South America and southwest Africa and protects the planet from high doses of solar wind and cosmic radiation.
The anomaly
Magnetic field of earth acts like a protective shield around the planet repelling and trapping charged particles from the sun. But over South America and the southern Atlantic Ocean, an unusually weak spot in the field called the South Atlantic Anomaly (SAA), allows these particles to dip closer to the surface than normal.
Mechanism
Van allen radiation belt: A Van Allen radiation belt is a zone of energetic charged particles, most of which originate from the solar wind. South Atlantic Anomaly exists because the Earth's inner Van Allen radiation belt comes closest to the planet’s surface, causing an increased flux of energetic particles.
Penetration of earth surface: Increased influx leads to the penetration of solar energetic particles deep into Earth’s atmosphere.
Effects of South Atlantic Anomaly
Satellite anomalies: The increased radiation levels can interfere with onboard electronics, potentially causing malfunctions or affecting the performance of satellite systems.
Increased radiation and exposure for astronauts: For manned space missions passing through or near the SAA, astronauts may experience higher levels of radiation exposure.
Aviation concerns: The increased radiation in the SAA can also affect high-altitude flights, particularly those that pass through polar route.Impact on Magnetic Compasses: The weakened magnetic field in the SAA can cause navigational issues for spacecraft and satellites that rely on
magnetic sensors or compasses.
Geography
South Atlantic Anomaly
General Studies Paper 1
Physical Geography
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