5:15 PM - 6:45 PM
[MIS06-P05] Characteristics of lighting estimated by infrasound observations in Bergen, Norway
Keywords:Infrasound , Norway western coast , Winter lighting , Lighting energy
In various regions, particularly Southeast Asia, heavy rainfall caused by cumulonimbus clouds has become increasingly severe in recent years. However, accurately predicting meteorological phenomena at the scale of cumulonimbus clouds remains challenging with existing observation networks and analysis models. Lightning, known to precede heavy rainfall by a few minutes, is considered a valuable clue for forecasting. This study aims to operationalize the use of lightning data for heavy rainfall prediction by comparing lightning data with meteorological data in terms of the energy. Observations were conducted using infrasound observations (infrasound sensors), which can estimate lightning energy and the position of thunder sources. Infrasound observation data obtained in Bergen, Norway, and analysis was conducted for a total of 7 events during the winter period from November 22, 2022, to March 15, 2023, and 23 events during the summer period from May 16 to July 22, 2023. The estimated lightning energy had average values of 3.0 MJ in winter and 1.7 MJ in summer. Winter lighting is stronger than summer, but the difference is lower than the previous study showed. In an event on February 9, 2023, a nearby lightning strike was observed approximately 1.5km away, and after a strong amplitude of 1.25 seconds, a 19.85-second ultra-low-frequency sound was recorded. This waveform is not shown in previous studies so far. These results not only demonstrate the validity of each observation method but also contribute to understanding the characteristics of lightning through estimation.