Variation of Surface Pollutants and Their Influence on Lightning Development in the Urban Cities of Northern India

Abstract

Lightning development and its variation with surface pollutants like particulate matter (PM₁₀), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂) were investigated in two urban cities of northern India, one from the high-altitude region Haldwani (Uttarakhand) and the other from Indo-Gangetic plain region, Agra (Uttar Pradesh). Lightning data is retrieved from Lightning Imaging Sensor (LIS) aboard the International Space Station (ISS) satellite for the period (2018–2022). Surface pollutants data is obtained from Uttar Pradesh Pollution Control Board for the same period. In the high altitude Haldwani region, it is observed that SO₂ is very well correlated (CC = 0.95) with lightning flash frequency compared to other surface pollutants PM₁₀ and NO₂ in the pre-monsoon season (March–May). Annual mean values of lightning and concentration of surface pollutants in both study regions indicate that lightning frequency is higher in the high-altitude region of Haldwani than Agra, which is situated in the Indo-Gangetic plain region of Uttar Pradesh. No significant correlation is observed between lightning and meteorological variables in Haldwani region. However, a significant correlation is observed between lightning and 2-m air temperature in Agra. A distinct relation is observed between lightning and surface pollutants in the high-altitude region of Haldwani and the Indo-Gangetic plain region of Agra. The present study shows that high concentrations of SO₂, associated with intense convection, are one of the reasons for the high lightning frequency in the high-altitude region of Haldwani.