Lightning Observation around Tall Structures in Kuala Lumpur, Malaysia

Abstract

This paper presents lightning observation around tall structures in Kuala Lumpur. As one of the fastest growing cities in the Southeast Asia, the growth in the number of skyscrapers may influence lightning activity in the area since tall structures are known to initiate lightning. This study aims to investigate lightning events around tall structures in Kuala Lumpur by analyzing data recorded by the lightning location system (LLS). In the study, the behaviour of the ground flashes were investigated and hotspots that coincided with tall structures in the area were identified. LLS data for the year 2020 were obtained from TNB Research (TNBR) and a total of 112,946 data were analyzed. Detailed investigation within 30 km radius from Kuala Lumpur showed that most of the lightning events consisted of negative flashes (92.4%) while positive flashes only contributed 7.6%. Despite the small percentage, positive flashes produced higher geometric mean and median peak current values of 30.8 kA and 31 kA, respectively. Negative flashes, on the other hand, produced lower geometric mean and median values of 23.7 kA and 23 kA, respectively. From our dataset, the highest peak current was recorded by a negative return stroke with a value of 302 kA while a positive return stroke recorded a value of 169 kA. A heatmap generated using QGis showed that indeed there were high lightning activities around the tall structures in Kuala Lumpur. The trend of the peak currents was also seen to be increasing with structure height. The increase in the number of lightning strokes around taller structures suggests their influence on the activity of lightning around the surrounding area. Due to this, proper consideration has to be taken when designing lightning protection systems for structures with greater heights.