Superlightning: What causes extremely powerful discharges?

Why distance plays a role is still unclear. Ephraim compares this phenomenon to a condenser. With this electrical component, energy is stored in the form of static electricity and released again at lightning speed. “There are two charged plates and some material or air between them,” he explains. When these plates are very close together, the electric field can become increasingly stronger and more conductive, Ephraim says, and when something similar happens in clouds, stronger lightning occurs.

A number of very similar studies and theories on this topic have appeared in the past. As explained previously The very high energy of lightning is due to the large difference between the salinity of water and soil. In the new paper, Ephraim and his colleagues argue that this theory does not explain why different salinities in the Atlantic Ocean and the Mediterranean Sea lead to similar numbers of superflashes. There are two other theories that provide a link between Aerosols rising from desert areasrespectively Spray over the sea Cloud formation. This should also lead to an increase in electrical charge. However, these theories explain the phenomenon only in certain regions, and not on a global level.

According to Ephraim, his team’s explanation fits more places where “superbolts” occur than other studies. However, it is not certain whether this also applies to conditions at the equator and in the North Pacific. “There are still many unanswered questions,” says Ningyu Liu, a professor of physics and astronomy at the University of New Hampshire, who was not involved in the new study. He points out that the study’s interpretation is valid for super lightning strikes that occur in the northeastern Atlantic Ocean and the Mediterranean Sea, but not for super lightning elsewhere. Liu asks: “Why are these two regions different from other regions above water?”

Michael Peterson, an atmospheric scientist at Los Alamos National Laboratory who was also not involved in the new study, suspects that the brightest large lightning strikes seen from space are caused by positively charged electrostatic discharges between clouds and the ground, whereas ordinary lightning is usually caused by negative phenomena. . Charged discharges between clouds and the ground.