The Probability of a Catastrophic Geomagnetic Storm is Lower than Thought, According to a Recent Scientific Paper

Mar 5, 2019


An image of active regions on the sun from NASA’s Solar Dynamics Observatory. The glowing hot gas traces out the twists and loops of the sun’s magnetic field lines.

According to a group of mathematical researchers, the probability that the sun will cause a storm capable of significantly affecting the electrical and communication infrastructures of the entire Earth in the next 10 years is "only" of 1.9% at most. Even so, it would be an event with serious consequences and governments should prepare themselves, say the scientists.

Three mathematicians and a physicist from the Universitat Autònoma de Barcelona (UAB), the Centre de Recerca Matemàtica (CRM) and the Barcelona Graduate School of Mathematics (BGSMath) have presented a mathematical model that allows to make reliable estimations about the occurrence probability of geomagnetic storms caused by solar activity.

The researchers, who published their work in the journal Scientific Reports (Nature group) this February, have calculated the probability of a potentially catastrophic event in the next decade for terrestrial telecommunications, such as the one registered between the end of August and early September 1859, the so-called "Carrington event". That year, astronomer Richard C. Carrington observed the most intense geomagnetic storm known to date. According to the new data, the probability of a storm of such magnitude in the next decade is between 0.46% and 1.88%, much less than what had been estimated so far.

"In 2012, the results reported in the scientific literature estimated a probability around 12%, ten times more than our most pessimistic estimate," explains the lead author of the study, postdoctoral researcher David Moriña. "Our model is more flexible than the previous ones, and also includes the model on which the previous estimates are based as a particular case," adds Moriña.

The intensity of the solar surface disturbances, such as solar flares and coronal mass ejection, affecting the Earth’s magnetosphere is measured since 1957 by means of an index called "DST", which centralizes the values collected every hour in stations distributed all around the planet. Normally, the value of this parameter ranges from -20 to +20 nT (nanoteslas, a billionth of a Tesla -a Tesla is more or less the magnetic flux generated by a powerful speaker). It is estimated that the DST index associated with the Carrington event had a value around -850 nT.

Geomagnetic storms are responsible for spectacular phenomena such as the northern lights that are observed in Earth’s highest latitudes and can interfere drastically with different aspects of human activity, depending on their intensity. Examples of serious disruptions that have occurred in the last decades are the interruption of electrical systems or satellite navigation and communication systems. "In Carrington’s time, the only infrastructure affected was the global telegraph network," says one of the authors of the study, Isabel Serra. "currently, a storm like that could have catastrophic results for our society. According to a 2013 study by the insurance company Lloyds and the Atmospheric and Environmental Research, the duration of the damage could reach more than a year, and the costs could reach 2.5 million dollars. These are numbers that should make us think ", insists the researcher.

"A probability around 2%, like the one we have calculated for a very intense storm, is not insignificant taking into account the consequences of this event", observes Professor Pere Puig, one of the authors of the article. "Governments should have protocols against disasters of this type, to inform and reassure the population that may be affected by the loss of power and disruptions in communications. Keep in mind that there will be very little response time before the unforeseen arrival of a storm of these characteristics. "

David Moriña and Pere Puig, researchers from the Barcelona Graduate School of Mathematics (BGSMath) and from the Mathematics Department of the UAB, Isabel Serra from the Centre de Recerca Matemàtica (CRM) and the Barcelona Supercomputing Center (BSC), participated in the study. Álvaro Corral, researcher at the Centre de Recerca Matemàtica (CRM), the Barcelona Graduate School of Mathematics (BGSMath) and the Complexity Science Hub in Vienna. David Moriña is financed by the Banco Santander-María de Maeztu Agreement.

Scientific article:

David Moriña, Isabel Serra, Pere Puig, Álvaro Corral. "Probability estimation of a Carrington-like geomagnetic storm", Scientific Reports (2019) 9: 2393. DOI: 10.1038 / s41598-019-38918-8​​