An unexpected increase in solar activity, which has resulted in an increase in solar flares and coronal mass ejections, has surprised scientists in recent weeks.
In recent days, solar storms of up to G3 level (categorized as strong, on a scale ranging from G1 to G5) have been recorded. On Saturday, September 16, an enormous filament was detached from the Sun at the same time that a coronal mass ejection was generated directed towards the Earth. Three days later, the Earth's magnetic field was affected by the arrival of the flow of particles emitted by the Sun, which led to the appearance of northern lights in regions of northern Europe and the United States.
This Tuesday, in the early hours of the morning, some areas of Kenya experienced disturbances in radio communications when a high-energy light flow generated by a solar flare arrived. A few hours later similar effects were repeated in Indonesia due to another solar flare. In one day, 18 of these phenomena were recorded in the world.
These disturbances occur because the Sun throws large flows of radiation and particles (mainly electrons, protons and helium nuclei) into space. If these emissions are directed to the region of space where Earth is at the time, they can affect communications systems and power grids.
These effects are collectively known as solar storms (or geomagnetic storms), and although solar flares and mass ejections from the Sun have always existed, it is now, in an increasingly technological world, that they can cause more damage big.
Since the 19th century it has been known that the activity of the Sun varies in cycles of around 11 years. A cycle begins with a minimum of sunspots (and associated phenomena, such as flares and mass ejections), and activity gradually increases until it reaches a maximum. From this moment on, the amount of sunspots begins to decrease to a new minimum, which marks the end of the cycle.
We are currently in solar cycle number 25 (the first was defined starting in 1755), which began in December 2019. At that time some organizations such as NASA or the National Oceanic and Atmospheric Agency of the United States ( NOAA) predicted a relatively mild cycle of solar activity (like the one that just ended, the least intense in the last 100 years). The maximum was predicted for July 2025, with an expected monthly sunspot count of 115 at the time of the maximum.
However, the number of sunspots has reached 159 in July this year and 115 in August. Everything indicates that we are at a level of solar activity unprecedented in the last 20 years and that the maximum of the current cycle could arrive next year, months ahead of the forecast.
Due to the growing importance of solar phenomena for technology, several organizations such as NASA, NOAA or the European Space Agency (ESA) monitor the sun's activity with terrestrial instruments and with satellites, with the aim to generate forecasts and warn of geomagnetic storms.
