Earth's new lightning capital revealed

Lightning as observed from the International Space Station CREDIT: ISS/NASA

Venezuela's Lake Maracaibo is Earth's new lighting capital, researchers have revealed.

The South American lake receives an average rate of about 233 flashes per square kilometre per year, according to a new study which used observations from the Lightning Imaging Sensor on board Nasa's Tropical Rainfall Measurement Mission. 

Researchers had previously identified Africa's Congo Basin as the location of maximum lightning activity.

The high resolution data set used to rank lighting hotspots was derived by 16 years of space-based observations, described in the Bulletin of the American Meteorological Society.

"We can now observe lightning flash rate density in very fine detail on a global scale," said Richard Blakeslee, LIS (Lightning Imaging Sensor) project scientist at Nasa's Marshall Space Flight Centre. "Better understanding of lightning activity around the world enables policy makers, government agencies and other stakeholders to make more informed decisions related to weather and climate."

“Lake Maracaibo has a unique geography and climatology that is ideal for the development of thunderstorms," said Dennis Buechler with the University of Alabama in Huntsville.

Mr Buechler noted that Lake Maracaibo is not new to lightning researchers. Located in northwest Venezuela along part of the Andes Mountains, it is the largest lake in South America. Storms commonly form there at night as mountain breezes develop and converge over the warm, moist air over the lake. These unique conditions contribute to the development of persistent deep convection resulting in an average of 297 nocturnal thunderstorms per year, peaking in September.

In 2014 the Catatumbo river, which flows into Lake Maracaibo, lightning phenomenon was approved for inclusion in the 2015 edition of Guinness World Records, dethroning the Congolese town of Kifuka as the place with the world's most lightning bolts per square kilometre each year at 250.

Africa remains the continent with the most lightning hotspots, according to the study, home to six of the world's top ten sites for lightning activity. The majority of the hotspots were by Lake Victoria and other lakes along the East African Rift Valley, which have a similar geography to Lake Maracaibo.

The study also confirmed earlier findings that concentrated lightning activity tends to happen over land and reduced lightning activity over oceans and that continental lightning peaks generally in the afternoon.

"Our research using LIS observations in new ways is a prime example of how Nasa partners with scientists all over the world to better understand and appreciate our home planet," said Mr Blakeslee.