Researchers in Russia have demonstrated that volcanic eruptions can influence the ionosphere far beyond their immediate surface area. Fine volcanic dust particles can disperse rapidly through the upper atmosphere and space, altering the distribution of electrons and creating temporary voids or “holes” in the ionosphere. This phenomenon was observed by a team from Schmidt Institute of Physics of the Russian Academy of Sciences, led by Doctor of Physical and Mathematical Sciences Sergey Shalimov. The finding adds a new dimension to how volcanic activity interacts with space weather and radio communication systems.
Following the January 2022 eruption of the Hunga-Tonga-Hunga-Khaapai volcano in the Tonga archipelago, the researchers monitored changes in the ionosphere over a broad corridor stretching from Australia toward the Kamchatka Peninsula. They employed ultra-long radio wave measurements to track variations in the amplitude and phase of low frequency signals. The initial expectation was that atmospheric waves would cause the observed fluctuations. However, the analysis revealed that dust ejected during the eruption was the primary driver of the irregularities in the radio signal, not internal atmospheric dynamics.
The team established that the volcanic plume contained material reaching altitudes much higher than the early models suggested. While early observations estimated a rise to approximately 30 kilometers, subsequent measurements showed that portions of the dust could be propelled into the lower ionosphere at about 60 kilometers above the Earth’s surface. In this region, the ionosphere is a seething mix of charged particles, where electrons move rapidly and ions respond more slowly. The charged dust particles acquire an electrical charge by absorbing or releasing electrons, and this charging process alters the local plasma environment. As a result, the pattern of radio wave propagation changes, and the signal can experience shifts in phase and amplitude. These changes manifest as holes or depletion regions within the ionosphere, which can scatter or attenuate radio waves that rely on the ionosphere for long-range transmission.
Why is this important? The ionosphere serves as a natural shield against certain high-energy cosmic rays, but disturbances within it can modify radiation exposure levels for high-altitude flights and satellite operations. When holes form in the ionosphere, navigation and communication systems that rely on radio signals can experience degraded performance. The dispersion of volcanic dust into the upper atmosphere also raises questions about the frequency and duration of such events. While most ionospheric holes tend to close relatively quickly, the observed occurrence after strong eruptions suggests that future climate-driven changes could influence their frequency or persistence, potentially increasing the risk for aviation and space-borne technology. Researchers emphasize the need to monitor these dynamics, as understanding the interactions between volcanic activity and the ionosphere helps improve models used for radio communication planning, aviation safety, and space weather forecasting. In the broader scientific context, these findings contribute to a more integrated view of Earth system processes, where geophysical phenomena on the surface can ripple through atmospheric layers and into near-Earth space, influencing systems that people rely on daily.