On July 3, 2026, the Local Lightning Detection Network (LLDN) measurement station was launched at the Central Geophysical Observatory of the Institute of Geophysics of the Polish Academy of Sciences in Belsk. The installation was carried out in collaboration between the Department of Atmospheric Physics, Department of Technical Support, and the Belsk Geophysical Observatory team by Piotr Barański, Jakub Wink, Paweł Czubak, Mariusz Chmielewski, and Radek Kiraga. An electric field measurement antenna with a recorder was installed on the roof of the main observatory building, and the entire system was operational in less than an hour. The installation aims to record radio signals generated by lightning discharges and to advance national research on the initiation processes of these discharges in thunderclouds.
The installation in CGO Belsk builds on years of work conducted at IGF PAS on the electrical structure of cloud-to-ground lightning and thunderstorm clouds. In 2008-2009, the Local Lightning Detection Network (LLDN, in Polish LSDWA) became fully operational, consisting of six identical stations located in various locations in Warsaw region. The entire project was funded by the national COST/204/2006 program for a consortium consisting of the Faculty of Electrical Engineering of the Warsaw University of Technology, the Institute of Geophysics PAS, and the Institute of Meteorology and Water Management- National Research Institute. The network was designed as a regional system for highly sensitive detection and digital recording of electric field signatures of lightning and cloud-to-ground discharges in the 20 Hz to 50 kHz band, complementing two routine lightning detection systems in operation in Poland, PERUN and LINET, for research purposes.
After the network was fully operational, some of the stations were used, and during various periods of operation, the measurement stations also operated in other locations in the Warsaw region, including: Belsk, Milanówek, Piaseczno and in IGF PAS Geophysical Observatory in Swider, in addition to the Warsaw stations located at the IGF PAS and the Space Research Centre PAS. Data from individual stations allowed for continued research on lightning discharges and the processes occurring in thunderclouds. These observations enable, among other things, spectral analyses of preliminary breakdown and leader stages of ground lightning strokes, as well as evaluation of the dipole moment of these strokes by comparing local electric field measurements with ELF radio observations.
The Belsk observatory rejoins the group of locations contributing to the lightning discharge research infrastructure developed by the Institute of Geophysics of the Polish Academy of Sciences since the operation of the LSDWA in the Warsaw area. This new installation not only expands observational capabilities but also continues long term measurements.
