ESA Swarm Discovers Rapid Change in Earth’s Magnetic Field

Key Takeaways

1. Swarm has achieved the longest uninterrupted magnetic field measurement from space since its launch in November 2013.
2. The South Atlantic Anomaly is expanding and now covers an area comparable to continental Europe.
3. A region southwest of Africa is experiencing a rapid decline in magnetic strength, raising concerns since 2020.
4. Areas of stronger magnetic fields have been identified in the southern hemisphere and two locations in the northern hemisphere, with varying strengths over time.
5. Understanding the Earth’s magnetic field is crucial for space safety as it protects us from cosmic radiation and solar particles.

Since it launched in November 2013, Swarm has been observing the Earth’s magnetic field. This satellite constellation is made up of three identical satellites. It has now set a new record for the longest uninterrupted magnetic field measurement from space.

Discoveries About the South Atlantic Anomaly

The satellite constellation has uncovered new information regarding the South Atlantic Anomaly, a region where the Earth’s magnetic field is considerably weak. Swarm’s observations indicate that this weak area has been steadily expanding from 2014 to 2025, growing to a size comparable to continental Europe.

Notable Weakening in Another Region

While the expansion of this weak area is alarming, Swarm also identified a different region southwest of Africa that has shown an even faster decline in magnetic strength. This area has seen a more rapid decrease in the Earth’s magnetic field since 2020, raising further concerns.

Areas of Stronger Magnetic Strength

Swarm’s data also highlighted regions with stronger magnetic fields. The southern hemisphere has one such area, while the northern hemisphere has two—one near Canada and another around Siberia. Over time, the magnetic field in Siberia has intensified, while the one in Canada has diminished.

The information gathered by Swarm is vital for scientists as they seek to comprehend the Earth’s magnetic field more thoroughly. With this data, they can explore the reasons behind the variations in magnetic strength in specific locations. The Earth’s magnetic field plays a crucial role in shielding us from cosmic radiation and charged particles emanating from the Sun, making its understanding essential for space safety. These findings have been shared in the journal Physics of the Earth and Planetary Interiors.