A solar flare erupted from an area with a dense magnetic field on the surface of the Sun, causing temporary radio signal disruptions across many regions in Australia and throughout New Zealand.
The M5-class solar flare, classified as moderate, was recorded by NASA’s Solar Dynamics Observatory emanating from sunspot AR3141 at 6:11 AM on November 7, according to Hanoi time. This storm generated a stream of radiation that ionized the Earth’s atmosphere.
Solar flare emitted from the surface of the Sun. (Photo: NASA).
Sunspots are dark regions on the Sun’s surface where strong magnetic fields are created by moving charged particles that twist into closed loops before abruptly breaking. The release of energy results in a stream of radiation known as a solar flare and a mass of material called a coronal mass ejection (CME). The CME associated with the flare on November 7 was not directed towards Earth. The flare appeared so unexpectedly that scientists were unable to provide advance warning of the event.
The National Oceanic and Atmospheric Administration (NOAA) classifies solar flares into five categories: A, B, C, M, and X, based on the intensity of X-rays they emit, with each class being ten times more powerful than the previous one. Upon reaching Earth, the X-rays and ultraviolet radiation produced by solar flares ionize atoms in the ionosphere, rendering this layer unable to reflect high-frequency radio waves, resulting in signal loss. Radio blackout occurs in areas illuminated by the Sun during the flare’s appearance and is graded from R1 to R5 based on severity. The most recent flare caused an R2-class radio blackout.
Astronomers have been monitoring solar activity since 1775. The Sun’s activity fluctuates in an 11-year cycle, and it has been particularly high recently, with the number of sunspots nearly double NOAA’s predictions. This increased solar activity releases high-energy plasma waves and X-ray streams that collide with the Earth’s magnetic field, leading to the loss of Starlink satellites, radio signal disruptions, and auroras in southern regions such as Pennsylvania, Iowa, and Oregon.
More solar flares are expected to impact Earth in the coming years. Researchers predict that solar activity will gradually rise, reaching a peak in 2025 before declining once again.
On the night of the solar storm, northern auroras will be much more visible than those in the south. This is because the Earth’s magnetic field is slightly compressed by high-energy charged particle waves, tearing magnetic field lines and exciting molecules in the atmosphere.
