Historical Analysis Shows Earth’s Vulnerability to Solar Storms
In November this year, people marveled at the sight of the northern lights in locations as far south as Italy and Texas. This stunning display was a result of a solar coronal mass ejection affecting Earth’s magnetic field and atmosphere. However, this event was relatively minor compared to a massive solar storm that occurred in February 1872.
The 1872 solar storm was a global event, causing auroras that were visible even near the equator in places like Bombay and Khartoum. An international team of scientists from nine countries recently released a comprehensive analysis of this significant historical event, tracing its solar origin and widespread terrestrial impacts.
Telegraph communications were widely disrupted by the storm in 1872. Today, with our heavy reliance on technological infrastructure, such a storm has the potential to disrupt power grids and satellite communications, causing widespread chaos and difficulties for urban areas.
“The longer the power supply could be cut off, the more society, especially those living in urban areas, will struggle to cope,” explained Designated Assistant Professor Hayakawa, the lead author of the study. Such storms have the potential to knock out the power grid, communication systems, airplanes, and satellites, making it extremely challenging for people to maintain their daily lives without that infrastructure.
Despite the rarity of such extreme storms, recent research has shown that they are more common than previously thought. Intense storms like the Carrington storm in 1859, the New York Railroad storm in 1921, and the Chapman-Silverman storm in 1872 are reminders of the potential threat posed by solar storms to our technologically dependent society.
A study led by an international team of 22 scientists used historical records and modern techniques to assess the Chapman-Silverman storm from its solar origin to its terrestrial impacts. The size and impact of the 1872 storm rivaled those of the Carrington storm and the NY Railroad storm, showing that the world has experienced at least three geomagnetic superstorms in the last two centuries.
As the Sun approaches the maximum of Solar Cycle 25, predicted to occur in 2025, we can expect enhanced auroral activity in the coming years. The preservation and analysis of historical records are crucial in understanding and mitigating the impact of such events, as the threat they pose to modern society is real. The international team’s findings were published in The Astrophysical Journal.