Study Links Tonga Volcano Eruption to Ionospheric Disturbances Impacting Satellite Systems

Satellite-based communication and navigation systems are critical for various sectors, including defence, agriculture, aviation, and disaster management.

A groundbreaking study has unveiled a previously unexplored connection between the massive eruption of the Tonga volcano on January 15, 2022, and the formation of Equatorial Plasma Bubbles (EPBs) over the Indian subcontinent. This research highlights the significant role that volcanic eruptions can play in triggering ionospheric disturbances, which can adversely affect satellite communication and navigation systems.

Satellite-based communication and navigation systems are critical for various sectors, including defence, agriculture, aviation, and disaster management. Understanding how natural disasters like volcanic eruptions impact the ionosphere is crucial for predicting and mitigating disruptions to these systems. While prior studies have established that EPBs can disrupt satellite signals, the influence of terrestrial events on space weather had not been extensively studied until now.

The Tonga volcano, located 65 kilometers (40 miles) north of Tongatapu, erupted with unprecedented force, sending shock waves through the atmosphere. Scientists at the Indian Institute of Geomagnetism (IIG) in Navi Mumbai, an autonomous institute under the Department of Science and Technology, investigated the subsequent formation of EPBs in the evening hours over the Indian region.

The researchers discovered that the eruption generated strong atmospheric gravity waves that propagated into the upper atmosphere, creating conditions conducive to the formation of EPBs. Using ionosonde observations from Tirunelveli and Prayagraj, they detected spread-F traces—irregularities in electron density in the ionosphere that lead to disruptions in radio signals. Satellite data from the Swarm B and C missions confirmed significant electron density depletions linked to EPB formation.

The study employed a comprehensive analysis of atmospheric and ionospheric data, utilizing observations from NASA’s Ionospheric Connection Explorer (ICON) to assess wind, ion density, and temperature variations. This multi-dimensional approach confirmed that gravity waves induced by the eruption played a pivotal role in initiating plasma instabilities in the ionosphere.

Additionally, the research identified enhanced Pre-Reversal Enhancement (PRE)—a sharp increase in the eastward electric field in the dusk sector—triggered by atmospheric disturbances, further illustrating the eruption's wide-ranging impact on the ionosphere.

The analysis of Total Electron Content (TEC) data from Global Navigation Satellite System (GNSS) measurements revealed gravity wave-like oscillations and Traveling Ionospheric Disturbances (TIDs) across Indian longitudes in the equatorial ionosphere, indicating that the volcanic eruption acted as a seeding mechanism for EPB generation.

Published in the Journal of Geophysical Research: Space Physics, this study underscores the need for continuous monitoring of space weather conditions in the aftermath of significant geological events, enriching existing knowledge of ionospheric dynamics. The research team, consisting of R.K. Barad, S. Sripathi, S. Banola, and K. Vijaykumar, emphasized that understanding the relationship between geological events and ionospheric behaviour is essential for the reliability of satellite communication technologies.

The implications of this research extend far beyond academic interest; it holds significant potential for enhancing forecasting methods for ionospheric disturbances, thereby improving early warning systems for satellite signal interference. This advancement could greatly benefit sectors reliant on Global Positioning Systems (GPS), including aviation and military operations, allowing governments and industries to better prepare for and mitigate disruptions in essential services such as GPS, air traffic control, and satellite communications.