“The level of activity here is the highest it’s been in about 20 years, since about 2003,” said Mark Miesch, a member of the solar modeling team at NOAA’s Space Weather Prediction Center.
If the Sun were to repeat its 2003 behavior, Earth could benefit, but it would also pose some problems. The 2003 Halloween storm brought dazzling green, red, and purple aurora borealis to California, Texas, Florida, and even Australia. It also disrupted more than half of all spacecraft orbiting Earth, irreparably damaged satellites, and caused communications problems for airlines and research groups in Antarctica.
While a sudden increase in the Sun’s activity may sound worrying, the Sun’s magnetic activity naturally waxes and wanes in an 11-year cycle known as the solar cycle. Almost halfway through the current solar cycle, the Sun is expected to reach its peak activity between January and October 2024, but its activity will probably reach its peak in 2025, or perhaps in 2026. It will become more active. Space Weather Forecast Center model.
And the upcoming peak should be a decent result compared to recent cycles. The momentum toward this “solar maximum” is already stronger than scientists thought, with an impressive punch of solar energy and particles being sent to Earth in 2023 and a rare aurora sighting in Arizona. was added. Already, solar flares and eruptions have been more pronounced than during the last solar maximum in 2014.
Still, scientists predict that peak activity intensity will likely be below or near average intensity compared to the long-term average, but it will still be exciting. .
“Some interesting things are going to happen in the next year or years,” said Scott McIntosh, a solar physicist at the National Center for Atmospheric Research in Boulder, Colorado.It will be the same as Halloween [2003], I don’t know. we have to prepare. ”
How do we know when the sun’s activity is at its peak?
After the solar maximum period has passed, the solar maximum period becomes obvious and the activity begins to decline. But observations of past solar cycles can help scientists understand what to look for quantitatively in advance.
One way to track the rise and fall of activity is to count the number of temporary dark spots on the sun’s surface called sunspots. Sunspots make up the Sun’s “active regions” and are often the source of large bursts of energy known as solar storms. Generally, as the number of sunspots increases, solar activity also increases.
“Sunspots are related to the sun’s magnetic activity,” said Miesch, who is also a researcher at the University of Colorado Boulder. Specifically, he said, it’s where the magnetic field passes from the sun’s interior (where it originates), through the surface, and into the atmosphere.
“We’ve known for about 150 years that when we look at the surface of the sun, the number of sunspots increases and decreases every 11 years,” says Miesch. During this period, the sun’s north and south poles swap places and the magnetic field reverses.
The beginning of the 11-year solar cycle is known as the solar minimum, when the number of sunspots and magnetic activity are at their lowest. Activity increases in the middle of the cycle, known as the solar maximum, and eventually decreases back to its minimum value.
The Sun is currently in its 25th solar cycle since observations began in the 1700s.
Over the past 24 solar cycles, the average number of sunspots during solar maximum has been about 179 in the peak month, Miesch said. (The last solar maximum in April 2014 was the weakest in this century and only peaked) There are only about 114 sunspots. )
The current solar maximum is predicted to last between 135 and 174 days in the largest month, which is slightly below average, said Miesch, who helped model the current solar cycle and its progression. That’s what it means.
However, some believe this is an underestimate. McIntosh and his colleagues predicted the maximum number of sunspots within the average range of NOAA-independent models. He said that within the margin of error, NOAA’s forecast is “close” to the average number of sunspots.
Miesch said the peak is expected to reach its peak in October 2024, but a NOAA model from January predicted solar activity and sunspot numbers would remain elevated until at least mid-2025. .
But predicting the sun’s movement can be more difficult than Houdini’s routine.
“We know a lot about the Sun, but we don’t know when the maximum will occur,” said Rachel Fillwett, an astrophysicist at Montana State University who is not involved in predicting solar cycles. “There is still considerable margin of error in making predictions.” .
But don’t worry. Even if this solar maximum ends slightly below average or arrives late, that doesn’t mean it’ll be boring.
In 2023, skywatchers got a sample of the solar hustle as a solar storm brought about rare auroral sightings in lower latitudes and disrupted radio signals. Other recent solar events have also knocked small communication satellites out of space.
Solar storms are called geomagnetic storms because they collide with Earth’s magnetic field and are ranked on a scale of G1 (slight) to G5 (extreme). At least one geomagnetic storm last year ranked her G4, making it the most powerful storm to hit Earth in recent years.
The question about this solar maximum is whether we will see a G5 storm.of Dramatic Halloween Storm of 2003comes from a past solar maximum and is ranked in G5.
“It’s the complexity that matters.” [active] Region of production. It’s not about the number of spots,” McIntosh said. If the strong geomagnetic storm of 2023 is a harbinger, the chances of even bigger storms are “pretty good,” McIntosh said.
It’s difficult to pinpoint exactly when major storms will occur. Mackintosh said that statistically speaking, it is normal for G4 and G5 events to occur when the sun is emerging from its solar maximum. Some of the greatest storms to ever hit the Earth occurred during the waning phase of the cycle.
Delores Knipp, an astrophysicist at the University of Colorado Boulder, said, “As we are passing the solar maximum, the chances of a direct hit on the Earth will increase.This is because there are many sunspots at low latitudes near the Earth.” It is because of this.”
Sunspots in their declining stages can become even more complex, Knipp said. When the Sun enters solar minimum, sunspots move from mid-latitudes to lower latitudes. She says some research suggests that this movement could cause crosstalk between the two hemispheres, leading to more magnetically complex eruptions on the Sun.
This is good news for aurora chasers. That’s because the potential for major storms continues for another year or two beyond the solar maximum (whether it occurs in 2024 or later).
Apart from the aurora borealis, the solar maximum will provide a unique opportunity to prepare for the total solar eclipse on April 8th. According to scientists, during a totality, the sun will generate an even larger stream of particles from its corona, which may be visible to solar eclipse observers.
“What we’ll see in the April eclipse will be a much more complex corona,” Miesch said.
This article is part of hidden planet, A column that explores the surprising, unexpected, and quirky science of our planet and beyond.