Overview

• The weak-field region has enlarged by an area roughly half the size of continental Europe since 2014, according to the newly published Swarm-based study.
• Researchers report faster weakening since about 2020 in a sector southwest of Africa, with parts of the anomaly drifting west at roughly 22 km (14 miles) per year.
• ESA attributes the uneven behavior to reverse flux patches at the core–mantle boundary, including one observed moving westward beneath Africa.
• Increased radiation in this zone raises risks for satellites and low-Earth-orbit astronauts, necessitating updates to geomagnetic models, though people at the surface remain protected.
• Swarm data also show a shrinking strong-field area over Canada (~0.65% of Earth’s surface) and growth over Siberia (~0.42%), and the healthy satellite trio is expected to keep delivering measurements beyond 2030.