Related data of CG lightning attachment process

More and more optical records have exhibited that multiple upward leaders
(MULs) occur frequently on a structure in the flash attachment
process. An interesting issue is why a structure can continue to
launch an upward leader (UL) after the first one appears. This
phenomenon is analyzed in the present paper. Considering the
influence of the leader behaviors on the ambient electric field, an
improved 3-D fine-resolution lightning attachment model with MULs is
established to simulate cloud-to-ground flash events with diverse leader
spatial morphologies. The simulation results show that MULs may
initiate almost simultaneously or with an obvious delay and the variation
range of UL length is large. From this, the flash events of lightning
terminating on a structure are divided into four scenarios and each
scenario is analyzed. It can be found that the spatial location of the
downward leader, the length and propagation direction of the
first UL and the time interval from the inception of the first UL
to final jump significantly affect the electric fields at top corners of
structure and further affect the inception of the second UL. Based on
qualitative analysis, four factors are proposed to explain why
the above four scenarios happen.