What is the Magnetic Field of Earth?

• Earth’s magnetic field, also known as the Geomagnetic field, is the magnetic field that extends from the Earth’s interior out into space, where it interacts with the solar wind, a stream of charged particles coming out from the Sun and repel them back into space.
• The magnetic field is generated by electric currents due to the motion of convection currents of a mixture of molten iron and nickel in the Earth’s outer core: these convection currents are caused by heat escaping from the core, a natural process called a Geodynamo.

What is Convection Current?

• Convection is one of the three main types of heat transfer, the other two being conduction and radiation. Unlike the other two, convection can only happen in fluids (i.e.- liquid and gas).
• To help you understand it better.

For example: Imagine it’s lunchtime, and you’re hungry. You decide to heat up a pan of soup on a gas stove. As the soup gets heat the molecule of soup starts moving rapidly. Because of this extra rise in temperature the molecules start moving away from each other and becomes less dense. As a result of this, hotter fluids become less dense than colder fluids. The soup near the bottom of the saucepan is hottest, because it is closer to the burner. This means that the soup is less dense at the bottom.
• Now, it is already known that, the matter which has less density floats on the surface of water and matter with high density sinks down. The same thing happens with the soup. The hotter, less dense soup at the bottom rises above the colder, denser soup. As the soup rises and gets further away from the burner, it starts to cool and become denser. Before long, the soup is dense enough that it sinks again–passing the rising hot soup on its way–and the whole process repeats. These movements in the soup are called convection currents.

• Now coming back to the topic, there is no soup boiling in pan inside our Earth’s crust rather, a mixture of molten iron and nickel cause rise of convection currents. These currents escape out from the Earth’s core. The escaping of these convection current is a natural process known as Geodynamo.
• Now that, you understood the background of the topic. Let us see what does the latest new report says.

Recent News and findings:

• Scientists have found the magnetic field from Africa to South America to be gradually weakening which is causing problems for satellites and space crafts in navigation.
• The phenomenon has been dubbed as the South Atlantic Anomaly by scientists,
• The data gathered by the European Space Agency’s swarm of satellites reveals that the area of the anomaly dropped in strength by over 8 per cent between 1970 and 2020.

What is causing weakening of magnetic field?

• One of the reasons for this could be a shift in the Earth’s magnetic field, whereby the North Pole and the South Pole switch places as the field reverses.
• This reversal last happened 7.8 lakh years ago, with scientists believing that a shift is long overdue. These reversals usually happen at an interval of 250,000 years.
• However, a study published in the scientific journal Proceedings of the National Academy of Sciences in 2018 found that despite the weakening field, “Earth’s magnetic field is probably not reversing”. Given that the reversal of a magnetic field takes tens of thousands of years of occurring, the exact cause for the weakening of the geomagnetic field is for now another of Earth’s mysteries yet to be ascertained.

What effect will the weakening of Earth’s magnetic field create?

• The Earth’s magnetic field also plays an important role in protecting the planet from solar winds and cosmic radiation that are harmful.
• The magnetic field of Earth protects the life of Earth from the harmful cosmic radiation and charged particles emitted from the Sun. Birds, turtles and other creatures also use the magnetic field of Earth to navigate.
• The navigation systems and mapping functions in smartphones may get affected.
• The telecommunication and satellite systems also rely on the geomagnetic field. Therefore, computers, mobile phones and other devices could also face difficulties. South in the compass could point to Canada and North to Antarctica.