Lightning, where does it
come from?
Since the dawn of time, lightning has been one of the Earth's most
exciting natural phenomenon. It's spectacular displays have given
entertainment and enjoyment to people all over the globe since the
beginning of mankind while still up to this day holding its mysteries
of ball lightning .
http://www.tbns.net/mediapoet/tech19b.h
http://homepages.wmich.edu/~m3nickel/lightning.jpg
Most people have experienced lightning and its counterpart thunder at some point in their
life, but at the same time may be confused as to the origin of the
bolts which they perceive. Lightning itself is composed of an
electrical charge, but where does it come from one might ask. During
the evaporation process, water molecules that come from the sea, lakes,
rivers and other sources rise into the air and condense into clouds. It
is not agreed upon in the scientific community, but according to http://science.howstuffworks.com/lightning2.htm,
one possible theory is that along the way these molecules experience
many collisions where they tend to lose and gain electrons. The freed
electrons gather along the bottom of clouds, while the positively
charged molecules rise and freeze in the upper portion of the
clouds. This is where the frozen molecules tend to lose more electrons
due to air currents rising. As the positively charged molecules rise
and the negatively charged electrons form along the bottom of the cloud
we have what is known as a Cloud's Charge
Separation. This charge separation would create the
possibility for a lightning stroke. An electric field forms around clouds
with charge separation with an intensity proportional to the amount of
charge build up within the cloud. As the field strengthens, it's field
of electro-negativity repels the electrons of the Earth's surface
enough to create a conductor of positive charges on the surface. The
field itself would then help to create the path from the cloud to the
Earth's surface for a successful strike of lightning.
http://www.weatherphotography.com
(c)Harald
Edens, reproduced with permission
The Electrical Field has an ionization effect on the air surrounding
the cloud, this spacing of positive ions and electrons turns the
air into a plasma like state, which is more conductive to electricity
than a normal atmospheric state. This creates the specific conditions
needed for the electrical charge to travel down from several kilometers
above the Earth.