Satellite navigation systems play a crucial role in guiding individuals along intricate routes when they’re on the road. By offering reliable directions, they assist drivers in navigating even the most convoluted paths. However, in the unfortunate event of an unexpected failure, these systems can leave drivers lost and may even cause accidents.
A new study reveala that the eruption of the underwater volcano Tonga has a disruptive effect on satellite signals. These signals are vital for GPS tracking systems, which accurately determine the positions of vehicles, boats, and aircraft.
A groundbreaking study conducted by an international team has shed light on a remarkable phenomenon: the disruptive impact of an underwater volcano eruption on satellite signals across vast distances.
The team’s findings, published in the prestigious journal Scientific Reports, reveal how an air pressure wave triggered by volcanic activity generates an equatorial plasma bubble (EPB) in the ionosphere, causing significant disturbances in satellite-based communications.
The ionosphere, a region in the Earth’s upper atmosphere, is a dynamic zone where solar radiation ionizes molecules and atoms, resulting in the formation of positively charged ions. Within the ionosphere, the F-region stands out as a crucial component, spanning an altitude range of 150 to 800 km above the Earth’s surface. This region plays a pivotal role in long-distance radio communication by reflecting and refracting radio waves from satellites and GPS tracking systems back to the Earth.
However, the delicate balance of the F-region can be disrupted by irregularities. During daylight hours, the ionosphere undergoes ionization due to the Sun’s ultraviolet radiation, leading to an electron density gradient that is most concentrated near the equator.
Yet, various disturbances, such as plasma movement, electric fields, and neutral winds, can trigger the formation of localized irregularities characterized by intensified plasma density. As these regions expand and evolve, they manifest as bubble-like structures known as equatorial plasma bubbles (EPBs). The presence of EPBs can introduce delays in radio waves and impair the performance of GPS systems.
Density gradients have long been suspected to be influenced by atmospheric waves, leading to the hypothesis that terrestrial events such as volcanic activity play a role in their formation. To investigate this theory, an international team of researchers, led by Designated Assistant Professor Atsuki Shinbori and Professor Yoshizumi Miyoshi from the Institute for Space-Earth Environmental Research (ISEE) at Nagoya University, in collaboration with NICT, The University of Electro-Communications, Tohoku University, Kanazawa University, Kyoto University, and ISAS, seized the ideal opportunity presented by the historic submarine eruption in Tonga.
Recognized as the largest underwater volcanic eruption ever recorded, the Tonga event provided the team with an unprecedented chance to examine their hypothesis. Leveraging advanced technologies, the researchers employed the Arase satellite to detect occurrences of Equatorial Plasma Bubbles (EPBs). Additionally, the Himawari-8 satellite was utilized to monitor the initial arrival of air pressure waves, while ground-based ionospheric observations enabled the tracking of ionosphere motion. Through their comprehensive observations, they observed an irregular structure of electron density spanning the equatorial region, coinciding with the arrival of pressure waves generated by the volcanic eruption.
The findings revealed “EPBs generated in the equatorial to low-latitude ionosphere in Asia in response to the arrival of pressure waves caused by undersea volcanic eruptions off Tonga,” adds Shinbori.
The group also discovered something unexpected. They demonstrated for the first time that ionospheric oscillations begin many minutes to several hours before the atmospheric pressure waves responsible for plasma bubble formation. This has significant ramifications since it implies that the long-held concept of geosphere-atmosphere-cosmosphere connection, which asserts that ionospheric disruptions occur only after the eruption, has to be revised.
The “new finding is that the ionospheric disturbances are observed several minutes to hours before the initial arrival of the shock waves triggered by the Tonga volcanic eruption,” points out Shinbori.
This finding suggests that the rapid propagation of atmospheric waves in the ionosphere triggers these disturbances even before the shock waves reach their initial destination. Consequently, it is imperative to revise the existing model to incorporate these fast atmospheric waves in the ionosphere.
“Therefore, the model needs to be revised to account for these fast atmospheric waves in the ionosphere.”
Additionally, they discovered that the EPB stretched well beyond what the conventional models had projected.
“Previous studies have shown that the formation of plasma bubbles at such high altitudes is a rare occurrence, making this a very unusual phenomenon,” Shinbori adds.
They “found that the EPB formed by this eruption reached space even beyond the ionosphere, suggesting that we should pay attention to the connection between the ionosphere and the cosmosphere when extreme natural phenomenon, such as the Tonga event, occur.”
The findings of this research carry profound implications, not only within the realm of science but also in the domains of space weather and disaster preparedness.
In the event of a significant occurrence like the eruption of the Tonga volcano, it has been observed that an unexpected breach in the ionosphere can manifest, even under circumstances that are typically deemed improbable under normal conditions.
Regrettably, such scenarios have not been accounted for in space weather forecasting models. Consequently, this study will make valuable contributions toward averting disruptions in satellite broadcasting and communication, stemming from ionospheric disturbances triggered by earthquakes, volcanic eruptions, and other similar incidents.
Source: 10.1038/s41598-023-33603-3
Image Credit: Getty