Jun 17, 2024 12:30:00

The Sun's magnetic field is set to reverse soon - what will the impact be on Earth?

The Sun's magnetic field reverses approximately every 11 years, and since the last time it did so in 2013, it is expected to reverse again within the next few years. Space news site 'Space' reports on the Sun's magnetic field reversal and its impact on Earth.

The sun's magnetic field is about to flip. Here's what to expect. | Space

https://www.space.com/sun-magnetic-field-flip-solar-maximum-2024

Solar cycle - Wikipedia
https://en.wikipedia.org/wiki/Solar_cycle

The activity of the sun can be observed by the number of sunspots, and periods with many sunspots are called 'solar maximum' and periods with few sunspots are called 'solar minimum.' Observations have shown that this activity cycle lasts about 11 years on average, but past records show that the period varies from 9 to 14 years, so 11 years is only a guideline.

Sunspots appear near the mid-latitudes of the Sun, and often appear in pairs, one leading sunspot in the direction of rotation and one trailing sunspot, forming a magnetic field with one north pole and the other south pole. The magnetic field is in opposite directions in the Northern and Southern Hemispheres, and for the 11 years between solar maximums, the magnetic field is always formed in the same direction in the same hemisphere, but when the solar maximum is reached, the magnetic field reverses and for the next 11 years, the magnetic field is formed in the opposite direction.

by NASA

During solar maximum, the magnetic field reversal starts near the poles and moves slowly toward the equator. In most cases, it takes one to two years for the magnetic field to completely reverse after it starts, but there are records of it taking as long as five years to reverse in the past.

During the solar minimum, the magnetic field will be close to a dipole with a north and south pole, just like the Earth. During the previous solar minimum, the magnetic field on the Sun was in the opposite north-south direction to the Earth, but during the next solar minimum, this magnetic field will reverse and point in the same direction as the Earth.

Unlike solar maxima, which are characterized by increased

solar flares and coronal mass ejections , and geomagnetic storms that increase the occurrence of auroras on Earth and cause damage to power lines and electronic systems , the magnetic field reversal is different from these phenomena and primarily benefits the Earth. The Sun's magnetic field changes the shape of the heliospheric current sheet , which becomes more wavy than usual during the magnetic field reversal, and it is said that this will better interfere with high-energy galactic cosmic rays that could harm astronauts operating outside the Earth's protective atmosphere.

by NASA

The reason why the magnetic field reversals occur is not yet clear, and it is also difficult to predict when solar activity will reach its maximum or minimum. However, it is known that the earlier the solar maximum occurs, the more active the solar activity. Scientists say they continue to monitor the sun's activity to predict future solar activity.