Characteristics of recoil leaders as observed by LOFAR

Lightning dart leaders and recoil are current pulses that propagate along previously established lightning channels reionizing the channel. They poorly understood since it is not known how a ionized channel can undergo dielectric breakdown multiple times. In this work we investigate five on two different using observations of LOFAR radio telescope in vhf (where observe 30--80 MHz) our TRI-D interferometric imaging algorithm. We show while do slow down over time average, they also clearly accelerate. addition, power emitted by leader closely correlated with speed. vhf-emitting width thinner than meter-scale resolution. This shows have significant streamer activity their core or at most very inner region corona sheath, there either little, weakly vhf-emitting, majority sheath. Finally, small microsecond-scale fluctuations occur same spot across subsequent channel, demonstrating propagation affected small-scale geometry.