Although solar flares occur quite frequently, they rarely produce truly catastrophic consequences. Nevertheless, they should not be underestimated. The historic Carrington Event of 1859 burned out telegraph lines across Europe and the Americas. Even recent incidents, however, demonstrate the vulnerability of modern technology. During the 2003 “Halloween Storms,” navigation systems operated by the U.S. Federal Aviation Administration (FAA) failed for 26 hours, prompting officials, for the first time in history, to warn airline passengers that radiation exposure at an altitude of 10 kilometers could rise to dangerous levels.
A new study by an international team of physicists led by NASA’s Goddard Space Flight Center and published in Nature has alarmed the scientific community. The researchers concluded that humanity and governments around the world have for years critically underestimated the worst-case scenarios of space weather because of a fundamental error in their calculations. It was previously believed that there was a natural upper limit to the amount of energy a solar storm could transfer into Earth’s polar ionosphere. To the researchers’ surprise, such a limit may not exist at all.
An Illusion of Safety
Study co-author Maria Walach, a lecturer in space physics at Lancaster University, notes that because superstorms are so rare, scientists have too little statistical data. Until now, physicists have relied on basic assumptions and interpretations that turned out to be incorrect.
Spacecraft such as the IMAP probe are used to provide advance warning of solar eruptions. They are positioned approximately one million miles from Earth at the gravitationally stable L1 Lagrange point. These spacecraft remain fixed relative to Earth and are the first to detect coronal mass ejections. However, measuring the strength of the solar wind at this location is similar to trying to assess the destructive force of an ocean wave at the shore by measuring its height in the open sea. The probes record particle parameters before the particles collide with Earth’s protective magnetic shield and undergo scattering effects, leading to systematic distortions in the data.
According to the study’s lead author, Nitin Sivadas of NASA, probability theory indicates that the real risks posed by severe space weather have been significantly underestimated because of the mistaken belief that the truth must lie somewhere between the measurements.
What the Satellites Show
To investigate the anomaly, the research team analyzed a dataset containing more than one million measurements collected by satellites operating directly within Earth’s magnetosphere, including the THEMIS, MMS, and Double Star missions.
The analysis found no statistical upper limit whatsoever on the amount of energy that can be transferred from the Sun to the upper layers of Earth’s atmosphere. Earth’s magnetic shield is highly effective at neutralizing ordinary solar activity. During an extreme storm occurring once every thousand years, however, these protective mechanisms may simply be overwhelmed.
Physicists warn that models of future space-weather threats must be urgently revised to account for the possibility that a solar storm could, in theory, have virtually unlimited destructive power, capable of disabling satellites, GPS networks, and the planet’s entire global energy system.
Earlier, we reported on how a powerful solar flare punched an enormous hole in the upper atmosphere.
According to Phys
