Solar flares are a sudden release of energy from the sun that can cause various effects on Earth. These flares are often associated with sunspots, which are dark patches on the sun’s surface. Sunspots occur when the magnetic field lines in the sun’s atmosphere become twisted and tangled. When these lines snap back into place, they can release a burst of energy that causes a solar flare.
What is a solar flare, and what causes them?
Solar flares are brief eruptions of energy on the sun’s surface. They happen most frequently close to the peak of the sunspot cycle, which is a period of increased sunspot activity followed by a period of decreased activity. The sun’s magnetic field becomes more chaotic during the sunspot cycle’s peak, and sunspots often form in groups. These sunspots can interact, causing a release of energy that results in a solar flare.
Solar flares can last for minutes or hours, releasing a tremendous amount of energy, and the largest flares can cause disruptions to power grids and communications systems on earth if the flare erupts in the direction of Earth. The strongest flares can even pose a radiation risk to astronauts in space, as well as airline passengers flying near the poles.
But don’t worry, most solar flares aren’t “earth directed,” or strong enough to cause more than pretty aurora in our skies. But they can cause problems with the technology we take for granted, like GPS.
The different types of solar flares
The sun is always active, but the activity waxes and wanes over time. The sun goes through an approximately 11-year cycle, during which sunspot activity increases and then decreases again. This cycle is known as the sunspot cycle.
During the peak of sunspot activity, solar flares are more likely to occur. Solar flares are bursts of radiation released when the sun’s magnetic field becomes unstable. There are three main types of solar flares: C-class, M-class, and X-class. C-class flares are the weakest type of solar flares that can affect Earth, while X-class flares are the strongest. M-class flares fall somewhere in between.
The scale is logarithmic, much like the Richter scale. So an M-Class flare is 10 times as strong as a C-Class flare, and X-Class Flares are 10 times as strong as C-Class Flares, and 100 times as strong as an M-Class flare! The NASA video below explains this in a bit more detail.
How solar flares can affect Earth
One of the most visible effects of solar flares is the aurora borealis or the “northern lights” in the Northern Hemisphere, and the Aurora australis in the Southern Hemisphere. These light displays are caused by charged particles from the sun interacting with Earth’s atmosphere. While the aurora borealis is typically only visible in high-latitude areas, intense solar flares can cause the northern lights to be seen as far south as Europe and the United States.
In addition to the aurora borealis, solar flares can also disrupt radio communications and power grids. This is because high-energy particles from the sun can interfere with electronic equipment on Earth. Solar flares are often associated with sunspot activity, and they tend to occur in cycles that last about 11 years. The next sunspot cycle is predicted to peak in 2024, so we may see an increase in solar activity over the next few years.
The dangers of a powerful solar flare
A solar flare is a magnetic storm on the sun’s surface that can release tremendous energy. This energy can be light, x-rays, and particles that are accelerated to high speeds. If a solar flare is powerful enough, it can cause auroras on Earth and disrupt electronic systems.
A major solar flare occurred in 1859, known as the Carrington Event causing auroras as far south as Cuba. The electrical currents caused by the solar flare were so strong that they set fire to telegraph wires and started fires in telegraph offices. There have been several powerful solar flares in recent years, but thankfully they have not been strong enough to cause significant damage on Earth.
However, scientists warn that if a sufficiently powerful solar flare were to occur, it could cause widespread damage to our electrical grid and other infrastructure.