资源环境科技发展态势分析平台

A record for an abysmally high number of lightning discharges in a single day occurred on 16 April 2019, where almost 58,066 flashes (cloud to ground + inter cloud) with a maximum of 179 flashes/min were observed over India. Researchers have hypothesized that an intense Western Disturbance (WD) caused these high numbers of lightning strikes, which prevailed in the northwestern part of India and spread over much of the country. Instead, here it is suggested and shown through multiple datasets that a dust intrusion into the storm altered cloud characteristics at the microphysical level, most likely favouring charge separation in cloud particles. The back trajectory calculation reiterated that there was a south-westerly transport of dust/ aerosol which converged within the secondary flow associated with the WD and lofted into the higher levels. It is hypothesized that the entrainment of dust acting as cloud condensation nuclei as well as ice nuclei induced a favourable condition for charge separation. Also a dust-boosting feedback loop was set up due to the prevailing intense WD which further accelerated the electrification process and led to catastrophic lightning.