Lightning does not always strike toward the ground. During powerful thunderstorms, rare electrical discharges can shoot upward into Earth’s upper atmosphere. These spectacular flashes, known as red sprites and blue jets, are part of a group of phenomena called transient luminous events (TLEs) that occur high above storm clouds.
Red sprites and blue jets are examples of transient luminous events (TLEs), brief flashes of light that occur above thunderstorms in the upper atmosphere. Although scientists have learned much more about these events over the past few decades, researchers are still studying exactly how they form and how they affect Earth’s upper atmosphere.
Long reported by pilots, the occurrence of these electrical storms was hard to document since they occur above thunderstorms. ESA astronaut Andreas Mogensen, the first astronaut from Denmark, was tasked during his mission on the International Space Station (ISS) with documenting red sprites and blue jets in order to understand more about them. Studying electrical storms that reach into the stratosphere is an important component for understanding how the Earth’s atmosphere protects us from radiation.
Known by different names, red sprites, blue jets, and elves are hard to document, lasting on average less than 20 milliseconds. Andreas Mogensen was able to film blue sprites occurring while observing a thunderstorm over the Bay of Bengal in India from the ISS.
The ISS offers an optimal observation point with its low orbit available at around 400 km altitude. Most satellites orbit around 800 km in altitude, making them unsuitable for this type of observation. Ground observations are difficult because these brief flashes occur high above thunderstorms and are challenging to detect from Earth’s surface. Andreas Mogensen was provided with detailed instructions on geographic coordinates of possible storm activity as well as which lens, filter and camera settings to use as part of Thor, a new thundercloud imaging system founded by the Technical University of Denmark.
Scientists continue to study red sprites, blue jets, and other transient luminous events using satellites, aircraft, and astronauts aboard the International Space Station. Each new observation helps researchers better understand the electrical processes above thunderstorms and how they interact with Earth’s upper atmosphere and near-space environment.
2017 research findings
The findings from this portion of the Thor experiment were published in 2017:
Chanrion, O., Neubert, T., Mogensen, A., Yair, Y., Stendel, M., Singh, R., & Siingh, D. (2017). Profuse activity of blue electrical discharges at the tops of thunderstorms. Geophysical Research Letters.
Reference
- Blue jets studied from Space Station, European Space Agency
