South Atlantic Anomaly (SAA) is a mysterious “dip” that can harm satellites and spacecraft, leading scientists to debate theories surrounding Earth’s magnetic pole reversal.
According to Science Alert, the SAA is still growing and requires NASA’s active monitoring. It is a vast area with a magnetic field strength lower than any other place in Earth’s magnetosphere, stretching across a large expanse of the South Atlantic from South America to Southern Africa.
“Magnetic dip” named “South Atlantic Anomaly” – (Image: GODDARD/NASA).
The magnetosphere serves as the planet’s protective shield, guarding everything from cosmic ray attacks. This SAA region over the ocean does not significantly affect living organisms, but it is “harming” satellites and spacecraft, including the International Space Station (ISS).
Without sufficient protection from the magnetosphere, the technological systems within spacecraft and satellites can short-circuit and malfunction when attacked by cosmic rays, such as high-energy protons from the Sun.
Minimizing that risk is one of the reasons NASA is monitoring the SAA. Additionally, they hope to uncover answers regarding this complex and perplexing phenomenon.
Geophysicist Terry Sabaka from NASA’s Goddard Space Flight Center explains: “The magnetic field is the sum of the magnetic fields from many current sources. The main source is a molten iron ocean within the outer core of the Earth. Its movement generates electric currents, which in turn create the magnetic field for the Earth, but it is not necessarily uniform.”
A dense rock reservoir located about 2,900 km below the African continent is believed to be the cause of the significantly weakened magnetic field in the area above.
According to geophysicist and mathematician Weijia Kuang, also from Goddard, the SAA may also result from the dominance of a “dipole field,” where a local field has an opposite polarity to the main field, causing the overall magnetic field strength to weaken.
Moreover, numerous studies worldwide over the past years have also linked the SAA to the magnetic North Pole event, which is moving from Canadian territory towards Siberia, Russia, shifting up to 50km each year. They suggest that this signals an impending magnetic pole reversal – the magnetic North Pole becoming the South Pole and vice versa – which has occurred multiple times throughout the planet’s history.
However, many groups dismiss the hypothesis of “Earth is about to reverse”, arguing that it is a recurring magnetic event that affected the Earth 11 million years ago.
Clearly, there are still many significant questions surrounding this magnetic anomaly, and scientists hope that the attention of the world’s leading space agency will help unveil its mysteries.
