Infrasound observation and propagation of recent meteoroid events 

Large meteoroids entering Earth’s atmosphere are a well-known source of infrasound. During the supersonic entry of space material into the atmosphere, shock waves are emitted from the trajectory as a line source. Explosive fragmentation of the meteoroid may additionally produce one or multiple point source events. Both types of shock waves propagate as low-frequency acoustic waves, also known as infrasound, within the atmosphere and to the Earth’s surface. Such infrasound signals can be detected by adequate instrumentation at distances of hundreds to thousands of kilometers, after long range sound propagation within atmospheric ducts.Using microbarometer arrays of national observation networks, like e.g. the Central and Eastern European Infrasound Network, and the International Monitoring System for the Comprehensive Nuclear-Test-Ban Treaty, such meteoroid events can be remotely identified, localized and characterized. Array signal processing using the Progressive Multi-Channel Correlation method and propagation modeling using Ray-Tracing and Parabolic Equation approaches are applied to estimate the origin of the acoustic signals along the meteoroid trajectories and to derive information about entry parameters and explosive yield.This study focuses on the infrasound observation, event analysis and sound propagation of recent meteoroid events, including the Southern Atlantic Ocean fireball on the 7th of February, 2022, the El Hakimia fireball over Northern Algeria on the 7th of May, 2023 and the Ribbeck fireball over Eastern Germany on the 21st of January, 2024.