Scientists have issued a new warning about the powerful impact of “head-on” interplanetary shocks on Earth’s magnetic field, which can cause stunning aurora displays but also threaten critical infrastructure.
The findings, published in Frontiers in Astronomy and Space Sciences, emphasize the need for improved forecasting to protect electrical systems from potential damage.
Understanding Interplanetary Shocks and Their Impact
Interplanetary shocks are disruptions in the solar wind caused by coronal mass ejections (CMEs) from the Sun. These CMEs are clouds of magnetic fields and charged particles that can travel through space at speeds up to 1,900 miles per second.
When these shocks hit Earth’s magnetic field, they can compress it, often triggering spectacular auroras. Dr. Denny Oliveira of NASA’s Goddard Space Flight Center, lead author of the study, explained, “Auroras and geomagnetically induced currents are caused by similar space weather drivers.
The aurora is a visual warning that indicates that electric currents in space can generate these geomagnetically induced currents on the ground.” These geomagnetically induced currents (GICs) can damage infrastructure that conducts electricity, such as power lines, oil and gas pipelines, railways, and submarine cables.
The study highlights the critical nature of understanding these shocks’ behavior. Interplanetary shocks that strike the Earth’s magnetic field head-on create stronger GICs than those that hit at an angle. This difference in impact is due to the more significant compression of the Earth’s magnetic field caused by frontal shocks.
As Oliveira noted, “The auroral region can greatly expand during severe geomagnetic storms. Usually, its southernmost boundary is around latitudes of 70 degrees, but during extreme events, it can go down to 40 degrees or even further, which certainly occurred during the May 2024 storm — the most severe storm in the past two decades.”
Measuring and Analyzing the Effects of Geomagnetically Induced Currents
Researchers used a comprehensive database of interplanetary shocks and cross-referenced it with readings from a natural gas pipeline in Mäntsälä, Finland, located within the aurora zone. This region is particularly susceptible to GICs during active solar events.
The data revealed that head-on shocks cause higher peaks in GICs compared to shocks that hit at an angle. This finding is crucial for understanding how to protect infrastructure effectively. The most intense GIC peaks occurred around “magnetic midnight,” when the north pole is between the Sun and Mäntsälä on Earth’s night side. This timing correlates with localized substorms that cause striking auroral brightening.
Oliveira further explained the significance of these findings: “Our work shows that considerable geoelectric currents occur quite frequently after shocks, and they deserve attention. Arguably, the most intense deleterious effects on power infrastructure occurred in March 1989 following a severe geomagnetic storm—the Hydro-Quebec system in Canada was shut down for nearly nine hours, leaving millions of people with no electricity.”
Implications for Infrastructure Protection and Future Research
The ability to predict the angles of incoming interplanetary shocks up to two hours before impact provides a crucial window for implementing protective measures for vulnerable infrastructure. Oliveira suggested, “One thing power infrastructure operators could do to safeguard their equipment is to manage a few specific electric circuits when a shock alert is issued. This would prevent geomagnetically induced currents from reducing the lifetime of the equipment.” This proactive approach could help mitigate the risks associated with GICs and ensure the continued reliability of essential services.
The researchers also highlighted the need for more comprehensive data collection to better understand the effects of these shocks. “Current data was collected only at a particular location, namely the Mäntsälä natural gas pipeline system,” cautioned Oliveira. “It would be nice to have worldwide power companies make their data accessible to scientists for studies.” Expanding the scope of data collection to include multiple locations and infrastructure types will provide a more complete picture of how interplanetary shocks impact different regions and systems.
Preparing for Increased Solar Activity
As we approach solar maximum, the period of increased solar activity, the frequency and intensity of interplanetary shocks are expected to rise. This makes it even more critical to develop accurate forecasting models and implement protective measures to mitigate the impact on infrastructure.
The study’s findings underscore the importance of understanding space weather phenomena and their terrestrial effects. By improving our ability to predict and respond to interplanetary shocks, we can better protect our infrastructure and ensure the continued reliability of essential services.
In conclusion, while the Northern Lights offer a beautiful natural display, they also serve as a reminder of the powerful forces at play in our solar system. By improving our ability to predict and respond to interplanetary shocks, we can better protect our infrastructure and ensure the continued reliability of essential services.
As Oliveira emphasized, “The aurora is a visual warning that indicates that electric currents in space can generate these geomagnetically induced currents on the ground.” This research not only advances our understanding of space weather but also highlights the practical steps needed to safeguard our technological infrastructure against its potentially harmful effects.
