Thunderstorm electric fields probed by extensive air showers through their polarized radio emission

• Main Authors: Trinh, T. N. G, Scholten, O, Bonardi, A, Buitink, S, Corstanje, A, Ebert, U, Enriquez, J. E, Falcke, H, Horandel, J. R, Hare, B. M, Mitra, P, Mulrey, K, Nelles, A, Rachen, J. P, Rossetto, L, Rutjes, C, Schellart, P, Thoudam, S, ter Veen, S, Winchen, T
• Format: Journal Article
• Language: English
• Published: 20-03-2017
• Subjects: Physics - Instrumentation and Methods for Astrophysics
• DOI: 10.48550/arxiv.1703.06008

We observe a large fraction of circular polarization in radio emission from
extensive air showers recorded during thunderstorms, much higher than in the
emission from air showers measured during fair-weather circumstances. We show
that the circular polarization of the air showers measured during thunderstorms
can be explained by the change in the direction of the transverse current as a
function of altitude induced by atmospheric electric fields. Thus by using the
full set of Stokes parameters for these events, we obtain a good
characterization of the electric fields in thunderclouds. We also measure a
large horizontal component of the electric fields in the two events that we
have analysed.