School;
of;
Earth;
and;
Space;
Sciences,;
University;
of;
Science;
and;
Technology;
of;
China,;
Hefei;
230026,;
China;
School;
of;
Earth;
and;
Space;
Sciences,;
University;
of;
Science;
and;
Technology;
of;
China,;
Hefei;
230026,;
China;
School;
of;
Earth;
and;
Space;
Sciences,;
University;
of;
Science;
and;
Technology;
of;
China,;
Hefei;
230026,;
China;
Chinese;
Academy;
of;
Meteorological;
Sciences,;
Beijing;
100081,;
China;
Chinese;
Academy;
of;
Meteorological;
Sciences,;
Beijing;
100081,;
China;
IC,; lightning; parameterization,; branched; bilevel; structure,; fractal; feature,; propagation; tendency.;