The sun’s magnetic field is about to flip. This happens roughly every 11 years and marks an important stage in the solar cycle. The last time this occurred was in 2013. But what causes this switch in polarity, and is it dangerous? Let’s take a deep look at the sun’s magnetic field reversal and investigate the effects it could have on Earth.
To understand the magnetic field’s reversal, it’s important to be familiar with the solar cycle. This cycle is approximately 11 years long and is driven by the sun’s magnetic field. During solar maximum, the height of solar activity, the sun’s magnetic field becomes more complex. As we shift toward solar minimum, the sun’s magnetic field returns to a dipole, albeit with flipped polarity.
The upcoming switch in polarity will be from the northern to southern magnetic field in the Northern Hemisphere, and vice versa in the Southern Hemisphere. This will bring it to a similar magnetic orientation to Earth, which also has its southern-pointing magnetic field in the Northern Hemisphere.
The reversal is driven by sunspots, magnetically complex regions of the sun’s surface that can spawn significant solar events. These sunspots have an orientation that matches the old magnetic field or the incoming magnetic orientation, following Hale’s law. The exact underlying cause of the flip remains mysterious, and the process is gradual, taking about a year or two for a complete reversal.
The sun’s magnetic flip is not instantaneous, and it won’t cause any apocalypse. However, we will experience some side effects, such as shielding Earth from galactic cosmic rays. As the sun’s magnetic field shifts, the “current sheet” becomes very wavy, providing a better barrier against cosmic rays.
Scientists will be monitoring the sun’s magnetic field reversal to predict future solar cycle strengths. If the bounce back into a dipole configuration happens quickly, the next cycle will be relatively active. But if the buildup is slow, the cycle will be relatively weak, like the previous Solar Cycle 24.
In conclusion, the sun’s magnetic field reversal is a natural phenomenon that occurs every 11 years. While it may have some effects on Earth, such as shielding us from cosmic rays, it is not a cause for alarm. Scientists will continue to study and monitor these changes to better understand the sun’s behavior and its impact on our planet.