ESS55
Prof.
Jin-Yi Yu
Negative
and Positive lightning Strokes
q Most of the lightning are negatively charged cloud-to-positively charged ground (negative lightning).
q But there are also positively charged cloud-to-negatively charged ground (positive lightning).
qWhen
high-level winds are strong,
thunderstorm clouds become
tilted and produce the positive lightning.
q The positive lightning can be
twice as
strong as the negative lightning.