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 The
Ocean We Live In consists of
four great regions of air -- troposphere,
stratosphere, ionosphere, and exosphere;
all life on earth is squeezed into the
lowest 20 miles of that ocean. |
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 A Barometer
is an instrument
for measuring atmospheric pressure. The
atmosphere exerts a pressure because air
has weight and is being pulled to the
earth by the force of gravity. For this
reason atmospheric pressure depends on
the height of air above the point at
which it is being measured and is lower
on top of a mountain than it is at sea
level. |
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 A Tornado
is defined as a violently rotating column
of air extending from a thunderstorm to
the ground, and can generate wind speeds
of 250 mph or more. |
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 Lightning
is a flash of light in the sky caused by
an electrical current that may flow
between parts of the same cloud, between
different clouds, or between clouds and
the earth. |
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