Observation of TLEs in Central Europe from Hungary Supported by LINET

Abstract

More than one hundred different transient luminous events (TLEs) i.e. sprites, sprite halos and one blue jet‐like emission have been observed in Central Europe at a new optical observation site in Sopron, Hungary, during the summer of 2007. The recently developed LINET lightning location network supplied information about the lightning activity in the region. This was the first time that data from this network was used to support TLE observations and to help interpret the results. TLE‐triggering lightning flashes were identified by their radiation in the ELF (Extremely Low Frequency) band, appearing as coherent transient signals with enhanced amplitudes in the monitored field components of the atmospheric electromagnetic field at NCK station in Hungary. Individual lightning flashes could be associated with 92% of the optically observed events. No ELF transient could be associated with the blue jet‐like emission, and for one sprite neither a corresponding transient nor any causative lightning flash could be found. Positive polarity lightning flashes were associated with almost all TLEs. In one exceptional case, a negative polarity parent lightning flash was associated with an ELF transient indicating a positive polarity source. In the present paper, the new optical observation site is introduced, the method of observation is described, and the potential role of LINET is discussed in connection with TLE research.