9.The Connection Between Red and Blue Lightning
Although most people’s imagination is captured by red lightning, it is intimately tied to another amazing higher atmospheric phenomena: blue lightning. Rising-propagating discharges from the tops of thunderclouds, blue jets and giant jets seem as blue cones or columns of light. Often seen in concert with red sprites, these blue events create a fascinating interaction of colours in the upper atmosphere. Red and blue lightning differs mostly in colour from the altitude at which these discharges occur and the atmospheric composition at such heights. Usually starting at lower altitudes (between 20 and 30 km), blue jets favour the emission of blue light from nitrogen molecules by thicker atmosphere. The discharge may turn crimson as it moves upward into the less thick atmosphere, producing an amazing visual show. Red and blue lightning events give important new perspectives on the vertical structure of the atmosphere and the propagation of electrical discharges over several atmospheric layers. Suggesting a complicated chain of events in the evolution of upper atmospheric electrical events, some scientists speculate that blue jets may be precursors or triggers for red sprite creation. Developing thorough models of atmospheric electricity and solving the riddles of how energy is distributed across various parts of the Earth’s atmosphere depend on an awareness of the link between these vivid discharges.
10. Red Lightning and Climate Change
Scientists are become more and more fascinated in how global warming can influence the frequency and features of red lightning as our planet deals with climate change. Although the link between red lightning and climate change is yet unknown, some possible links have been suggested. In many areas, rising global temperatures are predicted to intensify the frequency and intensity of severe thunderstorms, hence increasing the likelihood of more frequent red lightning episodes. Variations in atmospheric composition—especially those related to greenhouse gases—may change the electrical characteristics of the upper atmosphere, therefore influencing the development and spread of sprites and other transient light occurrences. Some research speculate that variations in the height of the tropopause—the border separating the troposphere from the stratosphere—caused by climate change could affect the height at which red lightning strikes. Furthermore changing the geographic location of red lightning hotspots could be changes in global circulation patterns and storm trajectories. Tracking variations in red lightning patterns over time could offer important signals of more general atmospheric changes linked with climate change. But the complicated character of atmospheric electricity and the rather limited observational record of red lightning events make it difficult to reach firm conclusions regarding long-term patterns. Understanding how this amazing phenomena may develop in a changing environment and what it might teach us about the condition of the atmosphere of our planet depends on ongoing research and long-term monitoring of red light episodes.
zi ang