Dr Silvia Vernetto (INAF Torino)
ARGO-YBJ is an air shower detector that operated from 2007 to 2013 at the Cosmic Ray Laboratory of Yangbajing (Tibet, China) at 4300 m a.s.l. devoted to Gamma Ray Astronomy and Cosmic Ray studies in the TeV energy range. During thunderstorms ARGO-YBJ observed significant variations of the flux of secondary particles of cosmic rays, strongly correlated with the local atmospheric electric field intensity. During the occurrence of the most intense episodes, increases of the triggered shower rate have also been observed. A study of the variation of the space-time features of showers during these events is in progress.