NASA Map Shows Where Lightning Strikes Most
Around the World
太空總署的地圖顯示雷電打擊最多的地區
Lightning strikes worldwide between 1995
and 2013. Areas with the most activity appear light pink. NASA
NASA has been
recording just about every lightning strike for much of the past 20 years, and
it has produced a map to show where this phenomenon is most common.
It turns out
that the eastern Democratic Republic of the Congo and Lake Maracaibo in northwestern Venezuela have the most
lightning. Both places have a lot of precipitation and the ideal humidity and
atmospheric conditions for thunderstorms to form, according to the NASA Earth Observatory.
As the map shows,
lightning is much more frequent over land than water, and it is more common in
the tropics, where there is more heat, and thus more energy for producing
storms. Areas that are lighter in color have more lightning, and some places
have as much as 150 strikes per square kilometer per year; one square kilometer
is about one-third the size of New York's Central Park.
The map was
produced using data collected between 1995 and 2013 by NASA’s Tropical Rainfall
Measuring Mission satellite and the OrbView-1/Microlab satellite.
Lightning is
formed within clouds. “As ice particles within a cloud collide and break apart,
the smaller particles acquire positive charge and the larger particles acquire
negative charge,” explains LiveScience, a science news site. “Updrafts of wind then
push the small particles upward, until the top of the cloud is positively
charged, while the bottom of the cloud is negatively charged. This separation
of charge creates a huge electric potential within the cloud, and between the
cloud and the ground.” Lightning is the discharge of electricity between cloud
and Earth, which diffuses this difference in potential.
Lightning strikes
over Lake Maracaibo, in Venezuela, which has some of the most frequent
lightning in the world.JORGE SILVA /
REUTERS
Condensed from Newsweek.
jUSTIN lAI (賴正雄)
07/23/2015
04/08/15 (Eng.)/ 全
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