The relationship of lightning radio pulse amplitudes and source
altitudes as observed by LOFAR
When a lightning flash is propagating in the atmosphere it is known that
especially the negative leaders emit a large number of Very High
Frequency (VHF) radio pulses. It is thought that this is due to streamer
activity at the tip of the growing negative leader.
In this work we have investigated the dependence of the strength of this
VHF emission on the altitude of the negative leader as observed by the
LOFAR radio telescope.
We find that the extracted amplitude distributions are consistent with a
power-law, and that the amplitude of the radio emissions decreases very
strongly with source altitude, by about a factor of 2 from
1~km altitude up to 5~km altitude. In
addition, we do not find any dependence on the extracted power-law with
altitude, and that the extracted power-law slope has an average around