The relationship between aerosol concentration and lightning is complex.
Aerosols can act as cloud condensation nuclei, contributing to the
formation of cloud droplets, cloud electrification and lightning, while
high concentrations of aerosols can contribute to a decrease in
lightning due to radiative effects. Meteorology plays a dominant role in
lightning activity, distorting the effect of aerosols. More
measurements, as presented here, are needed to establish the complex
relationship between aerosols and lightning.
The Po Valley, a heavily industrialized region, was highly affected by
the COVID-19 lockdown. The reduction of non-essential activities and
mobility coincided with a significant drop in pollutant concentrations
and lightning. We investigate the relationship between lightning,
meteorology and aerosols. We find that the variation in lightning during
the lockdown cannot be fully attributed to meteorology.
$\sim$60\% of the observed decrease can
be attributed to meteorology, and
$\sim$40\% to the reduction in aerosol