Imager of sprites/upper atmospheric lightning (ISUAL) is a scientific payload on the Taiwan's ROCSAT-2 satellite that aims primarily to provide crucial observation data on these TLEs from space. A single bolt of ordinary lightning, which is invisible to Swarm’s instruments, carries enough energy to charge 20 electric cars, but the energy produced by a transient luminous event would be enough to charge more than 800 vehicles.Upper atmospheric transient luminous events (TLEs sprite, elves, blue jet, etc.) are recently discovered thunderstorm-induced phenomena. “Although we know that every lightning strike carries a lot of energy, it is clear that this class of lightning is much more powerful. The accumulated electrostatic energy released and observed by Swarm was close to 120 GJ, which is equivalent to the energy released in the detonation of 29 tonnes of TNT. Such powerful sources include sprite-associated discharges. “Powerful ELF waves can even propagate around the world a few times and still be visible in our recordings. This is possible because of a very low attenuation of Extremely Low Frequency (ELF) electromagnetic waves that these discharges generate. Janusz Mlynarczyk, from AGH University of Science and Technology in Krakow, added, “Using the three stations of the WERA system, we are able to locate powerful atmospheric discharges that occur anywhere on Earth and reconstruct their most important physical parameters. However, Swarm can only do this if one of the satellites is in close proximity to the active thunderstorm and if the lightning is strong enough.” “Although Swarm’s main goal is to measure slow changes in the magnetic field, it is apparent that the mission can also detect fast fluctuations in the field. This means that some lightning bolts are so powerful that they trigger disturbances in Earth's magnetic field and propagate hundreds of kilometres upwards from the thunderstorm, reaching the altitude of Swarm’s orbit. Sprites seen over the Czech Republic and detected by SwarmĪ paper, published recently in Geophysical Research Letters, describes how scientists from research centres in Poland used magnetic field data from ESA’s constellation of Swarm satellites, lightning observations from the Geostationary Lightning Mapper and from the ground-based World Extremely Low Frequency Radiolocation Array (WERA) to provide evidence of links between transient luminous events and magnetic-field fluctuations in the upper ionosphere.Įwa Slominska, from a small company cooperating with Poland’s Space Research Centre, explained, “Lightning can generate ultralow frequency fluctuations that leak into the upper ionosphere. Gases in the ionosphere are excited by solar radiation to form ions, which have an electrical charge. The ionosphere is very active part of the atmosphere, responding to the energy it absorbs from the Sun. Scientists have long been interested in understanding if lightning propagating to higher in the ionosphere can cause fluctuations in Earth’s magnetic field. They appear as large, but weak flashes of red and usually happen at the same time as the cloud-to-ground lightning we all know. Sprites, for example are large electrical discharges that occur at an altitude of around 50–90 km, above large thunderstorm systems. There are several different types of transient luminous events such as sprites, jets and elves, each with their own characteristics. They are usually only captured by sensitive photographic equipment and, because they emit weak light, photographs can only be taken at night. They are very brief, lasting from less than a millisecond to two seconds, and rarely seen from the ground.

Transient luminous events are optical phenomena that occur high up in the atmosphere and they are linked to electrical activity in underlying thunderstorms.

Transient luminous events information