13. Blue Cones: The Funnel-Shaped Marvels of the Sky
Rare and very beautiful, blue cones show up as funnel-shaped discharges rising upward from the tops of thunderclouds. Though their conical form widens as it rises into the stratosphere, these events resemble blue jets.
The same mechanism generates the blue hue of these cones as that of other blue lightning events: excitation and consequent de-excitation of nitrogen molecules in the environment. The electrical discharge interacts with nitrogen at varying altitudes as it moves higher to produce a gradient of blue colours that can be really amazing to view.
Usually barely a fraction of a second, blue cones are short-lived yet can soar astonishingly 40 km beyond the cloud tops. Blue cones, according to scientists, might help to transport electrical charge between several layers of the atmosphere, therefore supporting the worldwide electrical circuit.
14. Blue Crawlers: The Horizontal Lightning Phenomenon
A rare kind of blue lightning, blue crawlers spread horizontally either inside or slightly above the cloud layer. Blue crawlers move laterally, producing complex patterns of blue light that seem to “crawl” across the heavens unlike vertical discharges such as blue jets or sprites.
The same process—excitation of nitrogen molecules by electrical discharges—produces the blue hue of these crawlers, same as other blue lightning events. But the horizontal migration of blue crawlers produces a unique optical impression, sometimes likened to a network of blue veins over the cloud surface.
Usually connected with big, intricate thunderstorm systems, blue crawlers could help to distribute electrical charge inside the storm. Though less frequent than certain other blue lightning events, blue crawlers offer important new perspectives on the three-dimensional electrical structure of thunderstorms.