Where lightning strikes most, and how lightning forms
Q: Where in the world do the most lightning strikes occur?
What position is South Africa in the list? (Jabulani, Johannesburg, South
A: Each year, lightning flashes about 1.4 billion times over
movie taken from the Space Shuttle Columbia shows Argentina under
fire. Hundreds of strikes flash along the storm’s 580-mile (930 km) front like a
scene from a war picture.
zaps within the cloud, from cloud to cloud, and from cloud to ground. Only about
30% of all discharges go from cloud to ground, says
E. Philip Krider,
professor of atmospheric sciences at the University of Arizona. Courtesy
For most landmasses, lightning strikes most often during the
summer. That, of course, limits the strikes. Not so in equatorial Africa — where
summer is year round, and lightning is a way of life. The spot with the most
lightning lies deep in the mountains of eastern Democratic Republic of the Congo
near the small village of Kifuka (elevation 3200 feet, 970 m). Thunderbolts pelt
a year, 158 bolts occur over each square kilometer (10 city-blocks square), says
Steve Goodman of NASA’s Global Hydrology and Climate Center (GHCC)
in Huntsville, Alabama.
The black dot (in the middle of the largest white area in Central Africa)
marks the spot — near the tiny town of Kifuka in the Democratic Republic of the
Congo — where the greatest lightning activity in the world occurs. The color
code at the top of the image shows the number of flashes per square kilometer
during the year. Note that over the oceans and desert "white" means no
lightning. [Courtesy of NASA’s Lightning Imaging Sensor (LIS) Instrument Team
and the Global Hydrology Resource Center (GHRC).]
homeland in South Africa doesn’t come close. The greatest flash density averages
only 36 discharges per square kilometer per year — only 23% of Kifuka’s rate,
says Goodman. This rate occurs at Costmore, located about 85 miles (135 km) west
of Durban, in southeastern South Africa.
Where lightning strikes Earth. Please click
here for a higher-resolution map. Courtesy of NASA’s Lightning Imaging
Sensor (LIS) Instrument Team and the Global Hydrology Resource Center (GHRC).
We can see how South Africa ranks in the lightning race by
checking the world map of strikes averaged from April 1995 to February 2003. It
does rank in the top 4th category (orange-red) but the world is full
of similar spots.
By the way, here’s how various continents rank according to
Country / State
strikes / km˛ / yr
Dem Rep of Congo
USA / Florida
NASA’s Lightning Imaging Sensor Instrument Team and the Global
Hydrology Resource Center (GHRC):
A map that shows where lightning hits over Earth
NASA Global Hydrology and Climate Center:
Observing lightning from space
NASA Global Hydrology and Climate Center: Lightning detection
from space: A
Flash facts about lightning
Q: What causes lightning? (Lanney,
Sandia Park, New Mexico)
Within the maelstrom of a thunderstorm, lightning is born. Ice and supercooled
water are the keys to the process, says
E. Philip Krider, professor of atmospheric sciences at the University of
Arizona. Violent winds buffet tiny hailstones as they form, causing them to
collide. When the hailstones hit ice crystals, some negative
from one particle to another. The smaller particles lose negative ions and
become positive and the larger more massive particles gain negative ions and
Lightning discharges an excess of positive and negative
charge within clouds, between clouds, or between clouds and the ground. Drawing
adapted from lightning article by Ron Hipschman.
"Ions (both positive and negative) have a lower mobility and a
longer lifetime than free electrons," notes Krider. So, the charges on the ice
particles tend to persist.
"The strong updrafts within thunderstorms carry the smaller
positively charged ice particles to the upper regions of the cloud while the
larger, heavier negatively charged (hail) particles collect in the lower and
middle portion of the cloud,"says atmospheric physicist
Steve Goodman of NASA’s Global
Hydrology and Climate Center (GHCC)
in Huntsville, Alabama.
This creates charge differences, like that between the
terminals of a car battery. When the potential difference between the regions
gets too great, lightning flashes, heating the discharge channel to sun-surface
temperatures. The air expands explosively, forms a shock wave, and thunder
cracks — nature’s sonic boom.
Lightning by Ron Hipschman
Benjamin Franklin and the first lightning conductors by E. Philip Krider
(Answered Dec. 13, 2005)