13. Sprites and Elves
Two of the most mysterious forms of high atmospheric electrical events, sprites and elves, present an original viewpoint on red lightning. High above the surface of Earth, in the mesosphere and lower ionosphere, these brief bright events strongly correlate with strong troposphere below lightning strikes. While Elves (Emission of Light and Very Low Frequency disturbances due of Electromagnetic Pulse Sources) seem as growing rings of red light at heights of 100 kilometres, sprites are vertical columns of red light that can reach from 50 to 90 kilometres in height. These red lightning events arise from a complex interaction between strong electromagnetic pulses produced by strong positive cloud-to- ground lightning strikes. Strong lightning strikes produce an electromagnetic disturbance that rises into the mesosphere and ionosphere. The excitation and ionisation of nitrogen molecules in the top atmosphere brought on by this disruption produces the distinct red glow of sprites and elves. The emission spectra of nitrogen when nitrogen returns to its ground state following excitation explains most of the red colour. Study of sprites and elves offers vital new perspectives on the electrical interaction between several strata of the environment for physicists and atmospheric scientists. These events show how much higher altitudes may get energy from lightning, therefore changing atmospheric chemistry and maybe even the entire electrical circuit of the Earth. Further helping us to grasp high-energy physics processes in the upper atmosphere and their possible effects on space weather and long-range radio communications is research on sprites and elves.
14. Derecho Wind Events
Characterised by their extensive and long-lived straight-line windstorms, derecho wind events produce a special atmospheric environment that can lead to the red lightning phenomena. Often referred to as inland hurricanes, these strong storms can span hundreds of kilometres and cause devastation wherever they pass. Red lightning during derecho outbreaks is intimately related to the strong atmospheric turbulence and electrical activity these storms produce. Usually accompanied by strong thunderstorms, a derecho generates a large wall of wind and rain as it passes across the terrain. Strong updrafts and downdrafts inside these storms cause notable charge separation, which prepares the ground for great electrical activity. Several elements are thought to affect the red hue of lightning seen during a derechos. The strong winds’ high quantity of dust and trash raised into the air can change the way light from lightning distributes and is seen. Furthermore influencing the spectrum of light released during electrical discharges are some atmospheric contaminants and particulates that the strong winds of the storm might concentrate. Studying red lightning in derecho events offers meteorologists and atmospheric scientists important new perspectives on the electrical character of these strong storms and their possible effects on communication networks and infrastructure. This study advances our knowledge of severe weather events and might assist to enhance warning systems and forecasting for these damaging winds. Moreover, the study of red lightning in derechos presents a special chance to investigate the relationship between global atmospheric dynamics and localised electrical events, therefore clarifying more general trends of atmospheric electricity and storm behaviour.
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