The South Atlantic Anomaly (SAA) is an area where the Earth’s inner Van Allen radiation belt (a protective zone of energetic charged particles originating from the solar wind that are captured by Earth’s magnetic field) comes closest to the Earth’s surface, dipping down to an altitude of 120 miles. This leads to an increased flux of energetic particles in this region and exposes orbiting satellites to higher-than-usual levels of radiation.
The effect is caused by the non-concentricity of the Earth and its magnetic dipole. The SAA is the near-Earth region where the Earth’s magnetic field is weakest relative to an idealized Earth-centered dipole field.
read more »
The Daily Omnivore 