A spatiotemporal analysis of lightning in the Bangkok Metropolitan Region

ABSTRACT This investigation analyzes the spatiotemporal lightning distribution from 2016 through 2020 for the Bangkok Metropolitan Region (BMR). Results suggest that significant urban augmentation of the lightning and subsequent thunderstorm distribution is occurring in the BMR. The distribution of lightning across the BMR is shaped by wind direction, wind speed and location of urban land cover. There exists a prominent two-peak (May and October) monthly distribution in the BMR lightning activity. October lightning counts are nearly double the amount occurring in May, with a lull in activity during July, August and the dry monsoonal months of December through March. However, both the number of lighting days and hours remain elevated from April through October, with thunderstorm lightning productivity highest in October, April, and September respectively. Lightning activity in the BMR is most frequent between 1100–1300 and 1900–2300 Local Standard Time. Significant enhancement of the lightning distribution occurs downwind of the Bangkok central business district and appears to be dependent on both the wind direction and speed. As wind speeds decrease, results suggest the spatial distribution of lightning strokes and lightning days become more focused over downtown Bangkok.