The Auger Engineering Radio Array (AERA) at the Pierre Auger Observatory with its 153 antenna stations distributed over 17 km2 is the largest experiment to measure the radio emission of extensive air showers.
The radio emission is known to be influenced by strong atmospheric E-fields such as those in thunderstorm conditions. Based on the measurement of the atmospheric E-field on the ground, criteria for the selection of affected events have been derived. A corresponding event selection has been studied with respect to the amplitude and polarization in comparison with simulations. In addition, selected events have been simulated with a two-layered atmospheric E-field model and compared with the measurements.