10. Blue Negative Streamers: The Downward Reach of Azure Light
One particular kind of electrical discharge seen in the lowest parts of thunderstorms are blue negative streamers. Often looking as thin, branching tendrils of blue light, these streamers spread down from negatively charged places inside the cloud. Although not as aesthetically arresting as some other blue lightning events, negative streamers are absolutely vital for the general electrical dynamics of thunderstorms.
The blue hue of these streamers results from the intense electric fields in the cloud ionising nitrogen molecules. Blue light is emitted by electrons removed from nitrogen atoms and then recombine. These streamers show the distinct azure hue produced by this procedure.
Predicting and investigating more extreme blue lightning incidents depends on an awareness of blue negative streamer behaviour. Often acting as predecessors to cloud-to- ground lightning strikes, these streamers can reveal important details on the charge distribution inside thunderstorms.