Strong Solar Flares Possible as Sunspot Develops Delta Magnetic Field

Space weather forecasters say strong solar flares could erupt from the sun on Tuesday due to a sunspot developing an unstable magnetic field.

Solar flares are flashes of radiation that explode from the sun's surface, usually from areas of the sun known as sunspots. Sunspots are solar regions that have particularly intense magnetic fields—so intense that they prevent some of the sun's internal heat from reaching the surface, giving sunspots a dark appearance.

Whenever these magnetic fields suddenly shift or realign, huge explosions of solar material can be emitted into space, and sometimes towards Earth.

One sunspot, in particular, called AR3078, has rotated around the sun's surface in recent days and is currently facing the general direction of Earth. What's more, observers noted that it has developed a particular kind of magnetic field that is associated with strong solar flares.

Solar flare
The sunspot AR3078 is seen above flashing brightly in the center-left of this NASA Solar Dynamics Observatory (SDO) image of the sun from August 15, 2022. Solar flares from sunspots have the potential to cause radio disruption. NASA/SDO/AIA

This is notable because solar flares have the potential to cause disruption on Earth. Since they carry high-energy radiation, solar flares can disrupt an electrically-charged region of our planet's atmosphere known as the ionosphere.

When the ionosphere is disrupted, so are high-frequency radio communications because radio engineers use the ionosphere to "bounce" radio signals around the world.

The particular type of magnetic field that AR3078 has developed is known as a delta field. Sunspots with delta fields are known to produce the most intense solar flares, and sunspots with this structure are often very big, according to the solar activity news website spaceweatherlive.com. At the same time, this type of sunspot also decays quicker than other types.

Early on Tuesday morning, the U.S. National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center (SWPC) recorded an M5 solar flare from AR3078 that was associated with a temporary moderate-strength radio blackout over parts of the Middle East and East Africa.

Potentially, a disruption of this strength could have caused loss of radio contact for minutes and degradation of low-frequency navigation signals for the same amount of time in affected areas, according to the SWPC.

However, there is a small chance that even stronger solar flares could erupt from AR3078, potentially reaching X-class strength—the strongest type. If so, there is potential for further radio and navigation disruption over Tuesday. The chance of an X-class flare from AR3078 is about 10 percent as of Tuesday, spaceweather.com said.

Solar flares in general are quite common and can even occur multiple times per day during times of peak solar activity. While potentially disruptive, they do not usually cause noticeable issues for the general public.

Solar flares are closely related to, but should not be confused with, coronal mass ejections (CMEs), which are also ejected from sunspots but move much slower, sometimes taking several days to reach Earth. CMEs can alter Earth's magnetic field, also causing communication issues and producing auroras.