Influence of topography on lightning density in Sumatra

Abstract

Lightning is one phenomenon that plays an essential role in weather modeling and forecasts. Moreover, lightning also has an impact on humans and facilities. Lightning shows variations both temporally and spatially. In this study, the spatial distribution of lightning in Sumatra was examined to see topography’s effect on lightning density in this region. We analyzed lightning data from the World Wide Lightning Location Network (WWLLN) observation. Topographic data, particularly the altitude and terrain slope data, were obtained from the digital elevation model (DEM) Shuttle Radar Topography Mission (SRTM). It was found that the lightning density is slightly correlated with the terrain slope and the altitude. High concentrations of lightning are observed in the land, consistent with some previous studies. Lower concentrations are seen on Sumatra’s western side, particularly in the hillside of the Barisan Mountains. Although Sumatra’s eastern side has a low elevation and a small topography slope, a high lightning concentration is observed in this region. The distribution of lightning shows seasonal variation in which the largest density is found during the dry season (MAM), which is different from the previous studies.