passes current between the two charges to
diminish the imbalance between them. This
is similar to what occurs during a buildup
of static electricity.
The lightning spark can take place between clouds, between the cloud and air, or
between the cloud and the ground, though
only 30 percent of all strikes are cloud to
ground (science.nasa.gov). Trees, cell phone
towers, steeples or the ground itself have
positive charges, and therefore are often
struck by lightning. Lightning bolts are
hot—their temperature can reach 50,000 degrees F (27,769 degrees C), which is hotter
than the surface of the sun. Objects struck
by lightning may catch fire or show little or
no evidence of burning at all.
Previously, scientists estimated that the
frequency of lightning on earth was about
100 times per second. With the advent of
widespread satellites that can detect lightning even in the most remote locations, we
now know that lightning occurs 44 times a
second on average. Nearly 1.4 billion flashes of lightning occur every year.
Lightning is distributed unevenly around
the globe. Much more lightning—about 70
percent—occurs in the tropics. These equa-
heats up the land surface faster than the
ocean. The heated land surface heats the air
above it, leading to stronger atmospheric
convection, thunderstorms and lightning.
The small village of Kifuka in the mountains of eastern Democratic Republic of
Congo (DRC) reputedly receives the most
lightning strikes of any place on Earth. On
average, this region receives 158 lightning
Neal Lineback
strikes per square kilometer (0.4 sq. mile)
a year. DRC lies at the heart of the world’s
and Mandy Lineback Gritzner
equatorial regions and therefore has warm
temperatures year round.
In the United States, Central Florida receives more lightning than any other area.
In fact, an area between Tampa and OrWhile the old adage that April showers
lando is known as “Lightning Alley.” Lightbring May flowers is often true, those showning Alley sees approximately 50 strikes per
ers can also bring something beautiful but
square mile (about 20 per sq. km) each year.
deadly—lightning.
As summer approaches in the United
Knowing where lightning occurs across
States, everyone should be aware of the
the Earth is important for many economic
danger of lightning. If caught in the open
and safety-related reasons. Every year lightduring a lightning storm, crouch down imning strikes kill approximately 2,000 people
mediately, keeping both feet on the ground.
and many farm and wild animals worldAvoid water and metal objects such as fencwide. In the United States, lightning is the
es, wires, power tools and railroad tracks.
second-highest storm-related killer, killing
Stay away from tents, golf carts, trees, hillabout two dozen people annually. Only
tops and open spaces. Find shelter in a buildflash floods
ing or car,
kill more.
never unLightder a tree.
ning causes
If you are
billions of
in a boat
dollars in
on a lake,
property
river or the
damage to
ocean, seek
buildings,
shelter on
commuland at the
nication
first sign of
systems,
thunder or
power lines
lightning,
and electriif possible.
cal systems
Lighteach year.
ning
is
It is a freone of the
©2010
quent cause
most sinisof
wildter threats
Flashes Per Square Km Per Year
fires
and
to outdoor
house fires
enthusi0.1-0.6
8-29
50+
0.7-1
2-7
30-39
40-49
and costs
asts. A little
Geography in the News 4/16/10
Source: www.science.nasa.gov
T. Smith/ C. Franko
airlines
common
billions of
sense can
Sources: http://environment.nationalgeographic.com/environment/natural-disasters/lightning-profile.html; and
dollars in
help mitihttp://geology.com/articles/lightning-map.shtml
delays, cangate
the
cellations
threat of a
and alternative routes to bypass storms.
torial regions are warmer than the poles
lightning strike.
Lightning is caused by an imbalance beand atmospheric convection is more prevaAnd that is Geography in the News™.
tween positive and negative charges. When
lent (the vertical movement of air caused by
April 16, 2010. #1037.
rain, ice or snow particles collide with one
heating at the surface). Thunderstorms and
Co-authors are Neal Lineback, Appalaanother during a storm, large electrical
lightning are widespread across the tropics
chian State University Professor Emeritus
fields build up in the clouds. When these
almost daily. Lightning almost never strikes
of Geography, and Geographer Mandy
electrical fields become large enough, a giat the north or south poles.
Lineback Gritzner. University News Diant “spark” occurs between them to reduce
Furthermore, more lightning occurs over
rector Jane Nicholson serves as technical
the charge separation. In essence, nature
land than over the ocean. Daily sunshine
editor.
Geography
In The
News™
LIGHTNING
STRIKES
Lightning Strikes Around the World
©2010 Maps.com