Science / Earth's magnetic field weakening, impacting orbiting satellites: Scientists

Science: Scientists say that earth’s magnetic field is gradually weakening which is resulting in technical disturbances in some satellites orbiting our planet.

The magnetic field is vital for life on earth as it protects us from the harmful cosmic radiation and charged particles emitted from the sun.

The field is mostly generated by the ocean of super-hot liquid iron that makes up Earth’s outer core, around 3,000 km below our feet. It creates electric currents that generate and change our electromagnetic field, according to the European Space Agency, ESA.

This field varies in strength and direction and over the last 200 years, it has lost around 9% of its strength.

However, scientists studying the phenomenon have observed that between 1970 and 2020, the magnetic field weakened considerably in a large region stretching from Africa to South America, known as the ‘South Atlantic Anomaly’. This area has grown and moved westward at a rate of around 20km per year.

The reason for the reducing magnetic field is not entirely known and researchers are using ESA’s Swarm constellation to improve their understating of this area.

Swarm satellites are designed to identify and precisely measure the different magnetic signals that make up Earth’s magnetic field.

“The new, eastern minimum of the South Atlantic Anomaly has appeared over the last decade and in recent years is developing vigorously,” said Jurgen Matzka from the German Research Centre for Geosciences.

“We are lucky to have the Swarm satellites in orbit to investigate the development of South Atlantic Anomaly. The challenge now is to understand the processes in the Earth’s core driving these changes,” he was quoted as saying in the ESA article.

According to the ESA, one possibility for the current weakening is a sign that Earth’s magnetic field is about to reverse – in which the north and south magnetic poles switch places.

Such events, however, are not new and have occurred many times throughout Earth’s history, roughly every 250,000 years. In fact, such a “geomagnetic reversal” is long overdue since the last one took place 780,000 years ago, according to a report in the Independent.

The Independent article says that the impact of such a geomagnetic reversal could be significant, given the role of Earth’s magnetic field in protecting the planet from solar winds and harmful cosmic radiation.

Also, telecommunication and satellite systems also rely on the magnetic fields to operate, suggesting that the computers and mobile phones could experience difficulties.

Another impact of the reversal will be on birds, turtles and other creatures that use the magnetic field to navigate, according to an article in The Daily Mail. North on a compass will also point to Antarctica rather than Canada, it reports.

The ESA team studying the South Atlantic Anomaly says that the present intensity dip is well within what is considered normal levels of fluctuations. However, satellites and other spacecraft flying through the area are more likely to experience technical malfunctions, so charged particles can penetrate the altitudes of low-Earth orbit satellites.