Overview
- A peer-reviewed analysis of 11 years of ESA Swarm measurements finds the South Atlantic Anomaly has expanded since 2014 by an area roughly half the size of continental Europe.
- The weak region behaves differently across its flanks, with stronger degradation toward Africa tied to reverse flux patches that turn magnetic field lines back into the core.
- Researchers highlight an intensified drop in field strength southwest of Africa beginning around 2020, increasing radiation exposure risks for satellites crossing the zone.
- Elsewhere the field is reorganizing, with a contraction of the Canadian strong-field region (~0.65% of Earth’s surface, about India) and growth over Siberia (~0.42%, about Greenland).
- The results, published October 3 in Physics of the Earth and Planetary Interiors, draw on Swarm’s continuous record, which ESA says remains healthy and supports navigation models and spacecraft risk monitoring.