Extreme Solar Storms May Cause More Damage Than In The Past

It is well known that a solar stormaccording to its level of power, it can affect operation of electric grids, control systemsor satellite communications. The problem is that it is not known what would happen today if the storm reached the level of the forecasters Carrington Event in 1859one of the most amazing things that happens only once every 1,000 years. New researchHowever, he suggests that the consequences may be worse than scientists thought.

Solar storms occur when the solar wind – a constant stream of particles ejected from the sun – interacts with Earth’s magnetosphere. During the Carrington Event, telegraph communications fell across half of the world, and the northern lights appeared in North America as far south as Cuba. Today, powerful solar storms can destroy many things and can even change the atmosphere.

“Our planet’s magnetic field does an excellent job of shielding us from many atmospheric conditions and is often only visible as glitches or beautiful auroras,” says Maria Walach, a researcher at Lancaster University who collaborated on the study. “However there are extreme cases, where satellites return to Earth unexpectedly, or we lose contact with GPS.”

To estimate the strength of the solar wind, researchers use measurements taken by satellites located at the L1 Lagrange point, about 1.5 million kilometers from Earth. The problem is that the observations don’t exactly match the environment where the solar wind interacts with the Earth’s magnetic field. A large amount of time passes between these two points, and the solar plasma also changes during its journey.

The authors argue that this uncertainty, rather than just experimental noise, causes systematic bias in the data analysis.

Solar Counters

The central point of the study lies in a well-known statistical phenomenon called regression towards the mean. In simple terms, the higher the rate, the lower the actual value it is trying to represent. This is because random uncertainty can sometimes exaggerate observations.

In the case of the solar wind, the strongest measurement made at L1 probably corresponds to a slightly weaker wind by the time it reaches the magnetic field. If scientists directly attribute the measurement of excess to the Earth’s response, the results will seem small compared to such a large influence. Repeated many times, this leads people to falsely believe that the magnetosphere stops responding as the strength of the solar wind increases.

What has happened is that, for many years, scientists have believed that there is a natural limit to the strength with which the Earth responds to severe hurricanes. According to that theory, when the solar wind reaches a high value, the Earth’s magnetic field ceases to play a role, and its response goes into a “multiplied” mode. However, this new study suggests that the limit may not have existed. What appears to be a physical phenomenon may be an illusion caused by the way the measurements are evaluated.

To test this hypothesis, the researchers developed a statistical model that includes the main sources of uncertainty: the difference in the time it takes for the solar wind to reach Earth and the random changes that occur during the journey. The model also reproduces in detail how the “multiplier” curves over a period of more than 25 years, without the need to use any method to suppress the Earth’s response.

They then used a technique known as regression calibration, which mathematically corrects for bias caused by measurement uncertainty. After the correction, the assumed saturation can be eliminated. The relationship between the strength of the solar wind and the geomagnetic response is also consistent, at least within the current range – more than a millionth, in fact.

There are no limits

What are the results of these results, as reported in the journal Nature? If the Earth’s response continues to grow in proportion to extreme events, extreme hurricanes such as the Carrington Event may be more dangerous than previously thought. The authors estimate that, due to the strong solar wind, the geomagnetic field could be almost twice as large as in previous models.

“If there is no upper limit on how the Earth responds to the solar wind, taking extreme scenarios into account should take this into account and we should be alert to the climate.” said Walach in a press release. “Fortunately, these extreme cases are rare, but this also means that we have very little information to work with and only time will tell what happens in such a dangerous, thousand-year-old event.”

Indeed, this study acknowledges that limitation: There is still very little documentation of high-risk events. For this reason, researchers do not say that saturation is impossible. Instead, they argue that the existing data do not provide sufficient statistical evidence for their existence.

This article appeared first WIRED in Spanish and translated from Spanish.