Published June 8, 2024

Photo courtesy

By Pooja Sainarayan

Local Journalism Initiative

The aurora borealis is a beautiful nighttime marvel that is worth travelling afar to observe. In fact, for most people it is the only way to come across “space weather.” Aurora activity is an indicator of ongoing geomagnetic storm conditions or solar flares. Solar flares are eruptions of energy, extreme ultraviolet light and x-rays that are caused by intertwined magnetic fields at the Sun’s surface. These magnetic fields can abruptly come undone or recombine producing the solar flares. X-class solar flares are the most intense type of flare the Sun produces.

A giant solar storm hit the Earth’s geomagnetic field on the first week of May, resulting in the most intense geomagnetic storm and longest displays of the aurora borealis seen in over two decades. After an approximate two-week break, the sunspot section that resulted in the intense storm seen in the beginning of May named Active Region 3664 (AR3664), had rotated back to face the Earth. Although appearing smaller than when we last saw it, the sunspot now renamed AR3697 still left quite a mark. On May 29th, the returned sunspot blasted out remarkably long intervals of solar flares, which lasted over an hour. According to the U.S. National Oceanic and Atmospheric Administration (NOAA) which assesses geomagnetic storms on a five-point scale, this geomagnetic storm was rated at an average G2 that peaked on Friday May 31st, compared to the severe G4 storm seen in early May. The AR3664 noted in the beginning of May, emitted nearly a dozen X-class flares. As the sunspot was going out of view by Mid-May, the emissions reached X8.7-class, the most powerful flare since 2017. Although the brightness and duration of the aurora activity seen the end of May was not the same as in the beginning, the forecast still showed a likelihood of spotting the northern lights throughout most of Canada.

Solar flares release high energy particles and radiation, amongst which energetically charged particles (high-energy protons) and electromagnetic radiation (x-rays) are the most dangerous emissions. On the surface of the Earth, we are shielded from these emissions by the Earth’s magnetic field and atmosphere. The x-rays from solar flares are halted way above the surface of our planet. However, they do disrupt the Earth’s ionosphere which consequently disrupts radio communications. In combination with energetic ultraviolet radiation, these emissions heat the Earth’s outer atmosphere, causing it to widen. Additionally, emissions and changes in the atmosphere can interfere with satellite communications such as the accuracy of Global Positioning System (GPS) measurements.

It is now known that most of the severe geomagnetic storms are caused by coronal mass ejections (CMEs), commonly associated with solar flares. The precise relationship between CMEs and flares is still not completely understood, as flares can trigger CMEs but sometimes CMEs can be observed without any flares. CMEs carry more material than flares throughout interplanetary space, raising the probability that these dangerous emissions interact with Earth. Solar flares alone produce high-energy particles close to the Sun, some which escape into space. However, CMEs drive a shock wave that can continuously release energetic particles as it spreads through space. When a CME hits the Earth, its impact disrupts the Earth’s magnetosphere, producing a geomagnetic storm. After it leaves the Sun, a CME normally takes three to five days to reach Earth. So, observing the correlated solar flare of ejection of CMEs from the Sun gives an early warning of geomagnetic storms.

Astronauts that are on a mission to the Moon or Mars are in serious danger from the energetic particles of flares. However, astronauts that stay relatively close to the Earth are not in immediate danger as they do not have to worry about the cumulative radiation exposure. A major problem with geomagnetic storms is the temporary loss of electrical power over a large area. The most well-known case of this occurred in 1989 in Quebec. The high flux in the magnetosphere causes elevated electric currents in power lines, exploding the transformers. This can occur more frequently at higher latitudes, where the induced electricity is greatest, and in areas that have longer power lines and where the ground’s conductivity is weaker.

The consequences of geomagnetic storms are more disruptive now than in the past due to our increased dependence on electronics and satellites that can be impacted by electric currents and energy particles up top in the Earth’s magnetosphere. In addition, the cost associated with repairing satellites and large-scale power grids can be very expensive and time consuming.

Scroll to Top