Study of the correlation between electrical activity and the microphysics and dynamsics of a real severe event using the WRF-ELEC model

Abstract

Atmospheric electrical activity is one of the most damaging meteorological phenomena. Studies suggest that storm electrical discharges are correlated with severe weather events such as hail, strong surface winds, etc. To study these correlations, in addition to real data, numerical simulations can be used. In this work, we investigated the electrical activity of simulated thunderstorms using the WRF-ELEC model over a case study of the RELAMPAGO field campaign (11 December 2018) associated with the occurrence of generalized deep moist convection in central Argentina including some supercell storms. The WRF-ELEC model successfully reproduced the convective event. A tracking algorithm was used to individualize different convective cells and to study the relationship between their electric activity and different microphysical and kinematic variables. The model reproduced the expected correlations and time lags between these variables. In particular, the model showed that the best correlation occurred between the graupel and hail mass and the electric activity of the storms; this is expected given the key role of these microphysical species in the charge separation processes. Also, 5 m·s−1 updraft volume and cloud top temperature (CTT) temporal evolutions presented good correlations with the electrical activity. Maximum updraft show a less but still good correlation with the electrical activity. We also investigated the correlation between the electrical activity and the hail and graupel concentration near the surface (as an indicator of hail precipitation) and the near-surface winds and we found that correlation is strong. In particular, for near-surface ice, we determined that peaks in electrical activity precede peaks in hail and graupel precipitation and that electrical activity could be used as a proxy of this high-impact weather event.