A huge and extremely fast-growing sunspot, AR3780, has been undergoing an extraordinary increase in size and is holding up excellent magnetic activity. That could be an indication that solar flares are heading toward Earth. This falls at the height of the 23-year cycle, during which the number of sunspots is highest. The average number of sunspots reached 196.5 in July 2024, the highest since December 2001.
Currently, on the southeastern side of the sun, AR3780 will rotate to face the Earth in a few days. That is when a more accurate measure of its size can be obtained, but it also increases its potency for solar flares and coronal mass ejections reaching Earth.
Sunspots are dark patches on the solar surface due to intense magnetic activity. They can be several times larger than Earth and many times appear in groups. The magnetic fields in and around sunspots can become twisted and stressed, and when these magnetic field lines are joined again, for instance, with magnetic reconnection, they release vast amounts of energy in the form of solar flares. This process can also propel large plumes of solar plasma into space, known as CMEs.
Solar flares can cause a break in radio communication, hurt satellites, and cause interference with GPS signals, while a CME can cause a geomagnetic storm. A geomagnetic storm in its turn may result in aurora and widespread blackouts. In their turn, G5s are the most intense and quite rare, though they may bring about some really serious consequences. G5 storms are extremely rare, said David Jess, a professor of solar physics from Queen’s University Belfast in Northern Ireland. On average, he said, only three to four G5 storms pop up for an 11-year solar cycle. Indeed, he mentioned that the last solar cycle, which ended in 2019, did not see any G5 storms at all.
The sun is now approaching its solar maximum, a periodic phase in its approximately 11-year cycle when the number of sunspots, solar flares, and other solar activities are at their most extreme. According to Martin Connors, a professor in the Department of Space Science and Physics at Athabasca University in Canada, the sun has had bursts of typical activity for when the sun is near solar maximum. He added that the frequency may remain like this for a year or so before declining.
The last major peak in sunspots back in 2001 was followed by the famous 2003 Halloween storms, which featured an X45 solar flare and G5 geomagnetic storms that caused power outages in Sweden. As the current solar maximum draws near, other strange solar phenomena are coming to light, like “sympathetic solar flares,” where two distinct sunspots emit solar flares simultaneously.
As the sunspot counts reached a 23-year high on March 25, scientists expect more Northern Lights displays in the coming weeks and months. The recent G5 geomagnetic storm on May 10, the strongest since 2003, made the Northern Lights visible across all 50 states in the United States, putting into evidence just how dramatically solar activity can affect Earth.
With the potential for disruption, scientists are watching the activities of the sun closely, warning and giving insight into the powerful solar events to lessen their impacts.