Lightning is an electrical discharge caused by imbalances between Storm clouds and the ground or within the clouds themselves. (Definition, Types, Causes, Distribution, Prediction) https://www.cda.org.bd

1. Lightning
Definition, Types, Causes, Distribution, Prediction
Prepared by Md. Nasim Fardous Zim
Centre for Disaster Aid (CDA)
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2. Lightning
Lightning is a natural event and
creates much energy.
Lightning is an electrical discharge
caused by imbalances between
• Storm clouds and the ground,
• or within the clouds themselves.
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3. Types of Lighting
There are three primary types of lightning, defined by what is at the "ends" of a flash
channel.
Intracloud (IC), which occurs within a single thundercloud unit
Cloud to cloud (CC) or intercloud, which starts and ends between two different
"functional" thundercloud units
Cloud to ground (CG), that primarily originates in the thundercloud and terminates on
an Earth surface, but may also occur in the reverse direction, that is ground to cloud
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4. Prediction
A lightning prediction system detects atmospheric conditions
likely to produce lightning strikes and sounds an alarm, warning
those nearby that lightning is imminent and giving them the
chance to find safety before the storm arrives in the area.
Lightning protection systems are often installed in outdoor
areas which are often congested with people, lack sufficient
shelter, and are difficult to evacuate quickly (such as water
parks, college campuses, and large swimming pool or athletic
field complexes). These locations are particularly dangerous
during lightning storms.
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5. Causes of Lightning
Lightning is an electric current. To make this electric current, first we need a cloud.
When the ground is hot, it heats the air above it. This warm air rises. As the air rises, water
vapor cools and forms a cloud. When air continues to rise, the cloud gets bigger and bigger. In
the tops of the clouds, temperature is below freezing and the water vapor turns into ice.
Now, the cloud becomes a thundercloud. Lots of small bits of ice bump into each other as
they move around. All these collisions cause a buildup of electrical charge.
Eventually, the whole cloud fills up with electrical charges. Lighter, positively charged particles
form at the top of the cloud. Heavier, negatively charged particles sink to the bottom of the
cloud.
When the positive and negative charges grow large enough, a giant spark - lightning - occurs
between the two charges within the cloud. This is like a static electricity sparks you see, but
much bigger.
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6. Distribution of Lightning
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7. Impacts of Lightning
• Lightning destroys crop fields and trees entirely
• When water in fractured rock is rapidly heated by a lightning strike, the
resulting steam explosion can cause rock disintegration and shift
boulders.
• Natural lightning makes X-rays in large quantities during the
propagation of stepped leaders.
• Nearby lightning can cause temporary blindness and severe hearing
problem
• Objects struck by lightning experience heat and magnetic forces of
great magnitude.
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8. Prevention of Lightning
You need to watch the full video that is given in the next slide for more prevention tips.
This may help you to keep safe.
Thank you.7/10/2018 8

9. Prevention for Lightning
How to survive a Lightning Storm
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10. Thank You
For Watching
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