New LIGHTNING Research
Researchers at the University of New Hampshire have found a unique set of events
that happens just before a lightning
flash. Their observation, called “fast negative breakdown”, documents a new possible way for lightning to form, and is the opposite of the current
scientific view of how air carries electricity in thunderstorms.
Recently, the problem of lightning initiation seemed to be solved
with the discovery of "fast positive breakdown" of air, which matched the theory long held by lightning researchers.
Fast positive breakdown involves the downward development of a pathway in the cloud, moving from the positive charge at the top of the cloud to the negative charge in the middle of the cloud. The pathway forms at one-fifth the speed of light and can trigger lightning.
However, the newly reported observation of fast negative breakdown shows that an upward pathway (going in the opposite direction and just as fast) can be created in a thundercloud, indicating there's another way to start electricity in the air. Ultimately, this provides scientists with a new view of what's possible inside a storm cloud.
These findings indicate that lightning creation, within a cloud, might be more bidirectional than we originally thought. These new understandings of how lightning forms might lead to better diagnostic and predictive capabilities.
“Fast negative breakdown in thunderstorms”
~ by Julia N. Tilles, Ningyu Liu, et al. (April 2019)
1 ➥ https://www.nature.com/articles/s41467-019-09621-z
2 “Fast positive breakdown in lightning”
~ by M. G. Stock et al (June 2017)