Assistant Professor Ivaylo Nachev from the Faculty of Telecommunications, a participant in the 33rd Antarctic Expedition, raised the flag of the Technical University of Sofia at the Bulgarian base “St. Kliment Ohridski” on Livingston Island. This is the largest Bulgarian expedition in terms of scientific objectives and team composition,
For the first time, a researcher from Bulgaria’s first polar astronomical project — Ivaylo Nachev, PhD from the Technical University of Sofia – joined the expedition to Antarctica. On Livingston Island, he installed scientific measurement equipment designed and developed at the Department of Radiocommunications and Video Technologies. This equipment is used for radio observations of the Sun as part of the project “Impact of Solar Activity on Ionospheric Dynamics and High-Energy Particle Fluxes over Antarctica.”
In 2025, the Sun is expected to reach its maximum within the current solar cycle, and the associated phenomena could cause geomagnetic storms, disrupt satellite operations, affect radio communications, and even impact Earth’s electrical grids. Observing solar processes during this period could contribute to significant insights into changes in future solar cycles and help establish connections between events on Earth—directly or indirectly related to solar activity—and the identification of relevant patterns. The current project, “Impact of Solar Activity on Ionospheric Dynamics and High-Energy Particle Fluxes over Antarctica,” is jointly organized by the Technical University of Sofia, the Institute of Astronomy with the National Astronomical Observatory at the Bulgarian Academy of Sciences, and the Nikola Vaptsarov Naval Academy. The project is funded under the National Polar Research Program “From Pole to Pole 2023–2025.” Its primary goal is the installation of an observation station on the Ice Continent to monitor the Sun in the radio-frequency range.
The observation system consists of several facilities, including antennas with associated peripheral hardware, designed at the Technical University of Sofia, with their performance optimized to account for the meteorological conditions on Livingston Island.
The facilities have high sensitivity.
For example, the system includes a sensor operating in the Hertz range (20–25 kHz) and a log-periodic antenna for high frequencies (50–1000 MHz), which continuously tracks the position of the Sun. The advantage of placing such equipment in the polar region is the opportunity for prolonged solar observation—up to more than 20 hours during the polar day. Another interesting facility is a sensor for monitoring Earth’s magnetic field in the Hertz range, allowing tracking of magnetic field variations and their correlation with solar activity. Additionally, radiation plates for detecting cosmic particles have been installed at various locations within the base. The CR-39 plates are configured to enhance their sensitivity, enabling the detection of alpha particles (through a triple-layer arrangement for the necessary thickness), neutrons (leaving direct traces easily readable after secondary processing), as well as gamma and X-rays. After chemical etching, ionizing radiation traces become visible, which are then analyzed under a microscope, providing insight into the radiation background around the base.
Radio-frequency observations of the Sun provide valuable data on coronal mass ejections, solar flares, and magnetic waves that influence space weather. Analysing this data will lead to a better understanding of the complex processes in solar-terrestrial dynamics, the relationship between Earth’s magnetic field, seismological processes, and ionospheric variations caused by or associated with solar activity. Additionally, the study will contribute to analyses of solar activity in the polar region. Understanding solar activity can also provide indirect insights into climate change and the speed at which these changes occur, potentially linking them to global warming.
