Analyses of negative cloud-to-ground flashes and their ground strike points in Austria

This paper presents an analysis of flashes and their Ground Strike Points (GSPs) by using Video and Field Recording System (VFRS) data and Lightning Location System (LLS) data from Austria. Analyses of the multiplicity of flashes and strokes per GSP have been performed. A comparison between strokes per flashes and strokes per GSPs has been conducted. By using the calculated strike point locations from the LLS, distances between different GSPs have been calculated. The used VFRS and LLS data set includes records from 2015, 2017, 2018 and 2021 recorded in the Austrian Alpine region. Atmospheric discharges have been recorded at 22 different measurement locations in Austria. For the present work a data set of 519 flashes including 1683 strokes were analyzed. Results for the mean multiplicity (3.3) revealed a lower value compared to multiplicities from other countries, but similar to the ones determined by former studies from Austria. Calculations of distances between the first GSP of a flash to the other GSPs of the same flash showed a median of 1.4 km, an arithmetic mean of 1.6 km and a geometric mean of 1.2 km. The maximum determined distance between two GSPs was 6.9 km for the analyzed data set.