14 DAY TRIAL // The upper atmosphere surrounding our planet is a very mysterious and difficult to analyze place. For many years, meteorologists and scientists analyzing phenomena that take place exclusively in storms and hurricanes were convinced that thunders and lightnings were the primary forms through which energy was released from the cloud. Over recent years, however, this was proven to be false, as various research groups identified luminous phenomena known as storm sprites and storm elves, which take place out of view. They can only be seen from high altitudes, or from low-Earth orbit.
But a team of scientists from Spain managed to capture not only highly-detailed video evidence of the elusive phenomena, but also slow-motion images depicting them. “This is the first time in Europe that we have been able to use high-speed video to detect transitory luminous phenomena taking place in the upper atmosphere – so-called sprites (in the form of a carrot or column) and elves (which are ring shaped),” explains for SINC researcher Joan Montanya. The expert is based at the Polytechnic University of Catalonia (UPC) Department of Electric Energy, and is also the coauthor of a new paper presenting the discoveries.
Details of the team's work appear in the latest issue of the esteemed scientific publication Journal of Geophysical Research. One of the main conclusions was the fact that there appeared to be considerably higher number of elves and sprites over sea than there were over land. It was additionally found that the energy these events produced was a lot higher for the sea-based ones and especially high during the winter. “All these phenomena are related with storms, particularly winter storms, but they only appear in mesoscale convective systems (usually in large fronts), which produce lightning with high levels of energy or extreme electric currents,” adds Montanya.
The scientist adds that sprites, for example, appear about 20 to 30 kilometers away from the site where a powerful lightning strikes. The phenomena last for about 40 milliseconds, and so catching them on tape is extremely difficult. “The observations made it possible not only to capture images of these short duration events, but also mean we can study the structure and dynamics of these highly unique electric discharges. Understanding the physics behind lightning and events associated with it will help us to protect ourselves better,” the expert concludes.