The Growing South Atlantic Magnetic Anomaly: Why It Matters

The South Atlantic Magnetic Anomaly (SAMA) over Brazil and the South Atlantic is intensifying.

This phenomenon results in a significantly weaker geomagnetic field compared to other regions. But why does this matter?

SAMA is expanding and deepening, which concerns scientists. The magnetic field here is much weaker than the global average.

This significantly impacts navigation systems. The exact cause of SAMA remains unknown.

However, the magnetic field intensity in this region drops to one-third of the global average.

This weakness leads to critical issues, particularly for satellite operations and radio communications.

The 2023 World Magnetic Model (WMM) report by NCEI and BGS notes a further decline in SAMA’s magnetic field intensity.

The anomaly’s center also shifted about 20 km westward. The affected area has grown by approximately 7% since 2020.

Why SAMA Matters

While SAMA poses no direct health risks or daily disruptions on land, it can harm satellites and affect radio wave propagation.

The reduced magnetic field intensity exposes satellites and navigation systems to high levels of cosmic radiation.

This exposure can cause failures in electronic components and onboard systems, leading to frequent malfunctions and even shutdowns.

SAMA also affects the accuracy of navigation systems relying on precise magnetic readings, such as compasses.

This has direct implications for critical communication and environmental monitoring technologies.

South America, particularly Brazil, feels the brunt of SAMA’s impact.

The anomaly’s weakness in this region can disrupt technology essential for communication and environmental surveillance.

The Reliability of the World Magnetic Model

The WMM, a spherical harmonic model of Earth’s main magnetic field, is developed by NCEI and BGS. It updates every five years to reflect magnetic field changes.

The accuracy of WMM2020 is confirmed until 2024. This reliability makes the WMM a crucial tool for navigation and directional reference, despite SAMA’s variations.

Data from the European Space Agency’s (ESA) Swarm satellite constellation monitor and predict magnetic field changes.