We present measured radio emission from cosmic-ray-induced air showers under thunderstorm conditions. We observe for these events large differences in intensity, linear polarization and circular polarization from the events measured under fair-weather conditions. This can be explained by the effects of atmospheric electric fields in thunderclouds. Therefore, measuring the intensity and polarization of radio emission from cosmic ray extensive air showers during thunderstorm conditions provides a new tool to probe the atmospheric electric fields present in thunderclouds.

Cosmic Lightning
International Conference on Acoustic and Radio EeV Neutrino Detection Activities
This work was funded by the The Netherlands Organisation for Scientific Research (NWO); grant id nwo/12PR3041-2 - Cosmic Lightning
Centrum Wiskunde & Informatica, Amsterdam, The Netherlands

Trinh, T.N.G, Scholten, O, Bonardi, A, Buitink, S, Corstanje, A, Ebert, U, … Winchen, T. (2016). Circular polarization of radio emission from air showers in thunderstorm conditions. In EPJ Web of Conferences. doi:10.1051/epjconf/201713503002