“Reverse” lightning 100 times stronger than normal lightning has been mapped  

The strange phenomenon of nature

“Upside down” lightning is a mysterious phenomenon of nature and unlike normal lightning, it does not fall to Earth but is directed towards space. We know very little about them since they are unpredictable and take place above the clouds. Thanks to a citizen, however, such lightning was recorded above the clouds during a storm in Oklahoma, USA in 2018, and with the data scientists were able to gather, they were able to study it extensively in three dimensions.

We managed to map this giant column in three dimensions with very high quality data. We were able to see VHF sources above the clouds, which we had not seen before in such detail. Using satellite and radar data, we were able to learn the location of the largest concentration of the plume above the cloud.

The fact that the lightning was detected by multiple systems, including the Lightning Mapping Array and two geostationary satellites, was a unique event and gives us a lot of information about the phenomenon. It is probably the first time that such a giant column has been mapped in three dimensions.

The “upside down” lightning started from the clouds at a height of 8 kilometers and reached ten times the altitude, near the Karman line where the Earth’s atmosphere ends and space begins. It carried 300 coulombs of electrical charge, when a typical lightning bolt carries only 5 coulombs. The temperature of the ionized air along the discharge reached 4,700 degrees Celsius, while the smaller plasma branches only reached 200 degrees.

The electrical connection of the clouds to the ionosphere carried a negative charge of the order of thousands of amperes per second. What we can see in the visible spectrum was limited to an altitude of 20 kilometers, but VHF transmissions reached 45 kilometers.

The VHF and visual signals confirmed what investigators suspected but had not yet proven. How the VHF emissions from lightning are emitted from the edge of the lightning, while the strong electric currents are much further back.

As to why some lightning travels upward instead of downward, it remains a mystery. Researchers suspect that there may be something blocking the lightning from moving toward the ground or other clouds.

For some reason, there is a barrier to cloud-to-ground blowdown. There is a concentration of negative charge and we believe that the conditions at the top of the storm weaken its upper layer which is normally positively charged. In the absence of the lightning discharge we normally see, the giant columns may release the concentration of excess negative charge.

The research was published in Science Advances .