![]() An overall increase in the number of geomagnetic storms this year has also caused the temperature in the thermosphere - the second-highest layer of Earth's atmosphere ― to reach a 20-year peak. For instance, on March 24, a "stealth" CME hit Earth without warning and triggered the most powerful geomagnetic storm in more than six years, which created vast auroras, or northern lights, that were visible in more than 30 U.S. Solar flares can also bring geomagnetic storms - major disturbances of Earth's magnetosphere caused by solar wind or CMEs. Related: 10 solar storms that blew us away in 2022 ( Solar flare classes include A, B, C, M and X, with each class being at least 10 times more powerful than the previous one.) The first half of 2023 logged more X-class flares than in all of 2022, and at least one has directly hit Earth. In 2022, there were fivefold more C-class and M-class solar flares than there were in 2021, and year on year, the number of the most powerful, X-class solar flares is also increasing, according to. (Image credit: Petr Horálek, Josef Kujal, Milan Hlaváč)Īnother key indicator of solar activity is the number and intensity of solar flares. The red ring surrounds a CME that erupted the same day. The ghostly lines of the sun's corona, or upper atmosphere, were clearly visible during a "hybrid eclipse" on April 20. While the bounty of sunspots is a major red flag, they are not the only evidence solar maximum could be here soon. In total, the number of observed sunspots has exceeded the predicted number for 27 months in a row. And in January 2023, scientists observed more than twice as many sunspots as NASA had predicted (143 observed versus 63 estimated), with the numbers staying nearly as high over the following months. In December 2022, the sun reached an eight-year sunspot peak. For instance, the number of observed sunspots has been much higher than predicted. In April 2019, the Solar Cycle 25 Prediction Panel, which is made up of dozens of scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA), released its forecast for Solar Cycle 25, suggesting that the solar maximum would likely begin sometime in 2025 and would be comparable in size to the maximum of Solar Cycle 24, which peaked unusually late between mid-2014 and early 2016 and was quite weak compared with past solar maximums.īut from the beginning, the forecast seemed off. Sunspots are almost completely absent at solar minimum and increase in numbers until a peak at solar maximum, but there's a lot of variation from cycle to cycle. "By looking at those sunspots we can get an idea of how strong and complex the sun's magnetic field is at that moment."Ī time-lapse image of two major sunspot groups moving across the surface of the sun between Dec. "Sunspots appear when strong magnetic fields poke through the surface of the sun," James said. To determine where we are in the solar cycle, researchers monitor sunspots - darker, cooler, circular patches of our local star's surface where coronal loops form. Related: Could a solar storm ever destroy Earth? ![]() This ushers in the end of the cycle and the beginning of a new solar minimum, James said. Sometimes, flares also bring enormous, magnetized clouds of fast-moving particles, known as coronal mass ejections (CMEs).Ī few years after the maximum, the sun's magnetic field "snaps" and then completely flips. These fiery ribbons can then snap as the sun's magnetic field realigns, releasing bright flashes of light and radiation, known as solar flares. As a result, the sun's magnetic field gradually weakens, and solar activity begins to ramp up: Plasma rises from the star's surface and forms massive magnetized horseshoes, known as coronal loops, that pepper the sun's lower atmosphere. ![]() (Image credit: NASA/Solar and Heliospheric Observatory)īut the magnetic field slowly gets tangled, with some regions becoming more magnetized than others, James said. A butterfly-shaped coronal mass ejection explodes from the sun's far side on March 10.
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