NASA has identified the South Atlantic Magnetic Anomaly (SAA) as a region off the coast of South America, where Earth’s magnetic field is significantly weaker. This weakening reduces magnetic shielding, exposing satellites and spacecraft to higher levels of radiation and posing a risk to their operation. Understanding the causes and implications of the SAA is essential for addressing these LEO challenges.

One hypothesis suggests that irregularities at the core-mantle boundary disrupt the geodynamo, the mechanism generating Earth’s magnetic field. The anomaly’s alignment with submarine volcanic features hints at possible links between mantle-crust interactions and magnetic disturbances. Additionally, a hotspot near the Mid-Atlantic Ridge corresponds to a geomagnetic intensity minimum at the core-mantle boundary, implying that thermal and compositional anomalies in the mantle may affect convection in the molten outer core, creating localized variations in the magnetic field.

Further research using subsurface imaging will help in uncovering the internal processes shaping Earth’s magnetic field and enhancing our understanding of the planet’s protective geodynamo.also assist in predicting magnetic anomalies and their effect on LEO space flight in the future.

Source: NASA. Graphic. Core Geomagnetic Anomaly, NASA.