The International Space Station (ISS) has a front-row seat to all the action in Earth’s atmosphere. Using this unique vantage point, there’s a new mission to analyze the dazzling thunderstorms of Earth’s upper atmosphere using its freshly installed Atmosphere-Space Interactions Monitor (ASIM).
Also known as the Space Storm Hunter, this piece of kit consists of a collection of optical cameras, photometers, X-ray detectors, and gamma-ray detectors. It looks to provide scientists with some rare insights into how heavy thunderstorms affect the Earth’s climate, atmosphere, ionosphere, and its radiation belts. Hopefully, it will produce some incredible imagery too.
“High-altitude observation allows us to study these events without the obscuring clouds,” principal investigator Torsten Neubert of the National Space Institute of the Technical University of Denmark said in a statement.
“With ASIM we will better understand the complex processes of upper-atmospheric lightning, which are also elements of ordinary lightning, although they take on different forms. This understanding can improve technology for detecting ordinary lightning.”
Thunderstorms in the upper atmosphere are very different to the crackling flashes of lightning you see during a heavy rainstorm on a hot evening. Instead, you'll see a number of differently brightly-colored bursts of electrical energy, known as sprites, elves, and giants.
Sprites are flashes of light that appear high up above thunderstorm clouds. They typically appear as a wispy red or purple glow. The red coloring comes from the excited electrons colliding with nitrogen molecules in the upper atmosphere and ionizing them. A single thunderstorm could produce several hundred of these in a night.
Cruising in low-Earth orbit at an altitude of around 400 kilometers (248 miles), the ISS is in a prime position to observe upper-atmosphere thunderstorms, which generally occur under an altitude of 100 kilometers (62 miles) in the Earth's ionosphere, mesosphere, and stratosphere. It also offers complete coverage of tropical and subtropical regions of Earth, usually where the most intense thunderstorms form, which have been hard to access.
“We will learn more about thunderstorm clouds and more of the fine-structure of the stratosphere and mesosphere, of which little is known,” Neubert added.
“These are solid scientific results documenting for the first time how active the tops of thunderclouds can be."