Advertisement
4. The Mysterious Blue Jets of the Upper Atmosphere
Advertisement
Blue jets are an uncommon and poorly known type of lightning occurring high above the clouds in the rarefied air of the upper stratosphere. Rising from the summits of thunderclouds, these brief, cone-shaped flashes of blue light travel distances of up to 50 kilometres in a fraction of a second. Originally observed by researchers in 1989, blue jets have attracted great attention and conjecture ever since. Blue jets flow from the cloud tops towards the ionosphere unlike ordinary lightning, which passes between clouds or from clouds to the ground. Molecular nitrogen emissions in the rarefied air of the upper atmosphere produce its unusual blue hue. Still up for discussion among atmospheric scientists is the precise mechanism behind blue jets. Some ideas propose they might be part of the global electrical circuit, balancing the electrical charge between the ionosphere and the ground. These elusive blue flashes remind us of how much we still have to discover about the intricate electrical events taking on in the atmosphere of our planet as long as research is under progress.
