Seasonal Distribution of Thunderstorm Activity in the Southern Region of Peninsular Malaysia

Abstract

This paper comprehensively analyses the thunderstorm activity in southern Peninsular Malaysia from 2011 to 2018 utilizing lightning data from the Lightning Detection Network System (LDNS) managed by TNB-Research (TNBR). Employing statistical analysis with Microsoft Excel and Python 3.9, this study aims to evaluate and characterise the regional CG lightning, considering geographical, temporal and climatic factors and their relation to seasonal variations. Negative cloud-to-ground (-CG) lightning dominates at 98.00 %, with only 2.00 % positive cloud-to-ground (+CG) lightning. Monthly trends exhibit a double-peak characteristic, with primary and secondary maxima in April and October, respectively, coinciding with monsoon transitions. The first inter-monsoon (IM1) emerges as the most active period, with +CG lightning contributing 28.40 % of total CG lightning compared to -CG lightning at 71.60 %. This study emphasizes critical implications, including polarity imbalance, doublepeak distribution, and seasonality. The significant disparity between +CG and -CG lightning necessitates further investigation into charge separation mechanisms within the clouds, particularly during IM1. The presence of double-peak feature in the monthly variation underscores the significant influence of monsoon dynamics on lightning activity initiation. The dominance of IM1 in total CG lightning and the high percentage of +CG lightning emphasize the need for enhanced lightning protection measures and preparedness during critical months, improving lightning risk assessment, public safety and infrastructure resilience. Future studies should focus on employing advanced meteorological models to explain the charge separation and polarity variations.