They use cosmic rays to study tropical cyclones like never before

Oct. 7 () –

For the first time, high-energy muon particles created in the atmosphere have allowed explore storm structures in a way that traditional visualization techniques cannot.

The detail offered by this new technique could help researchers model storms and related weather effects. This could also lead to more accurate early warning systems.

A team of researchers, led by Professor Hiroyuki Tanaka of Muographix at the University of Tokyo, offers meteorological science a novel way to detect and explore tropical cyclones. using a quirk of particle physics that takes place above our heads all the time.

“You’ve probably seen pictures of cyclones taken from above, showing swirling cloud vortices. But I doubt you’ve ever seen a cyclone from the side, maybe as a computer graphic, but never as real data captured by sensors,” Tanaka said.

“What we offer the world is the ability to do just this, visualize large-scale weather events like cyclones from a 3D perspective, and also in real time. We do this using a technique called muography, which can be thought of as an X-ray, but to see into truly enormous things.”

Muography creates X-ray-like images of large objects, including volcanoes, pyramids, bodies of water and now, for the first time, atmospheric weather systems. Special sensors called scintillators come together to form a grid, a bit like the pixels on your smartphone’s camera sensor. However, these scintillators do not see optical light, but particles called muons that are created in the atmosphere when cosmic rays from deep space collide with atoms in the air.

Muons are special because they pass through matter easily without scattering as much as other types of particles. But the small amount that is deflected as they pass through solid, liquid, or even gaseous matter can reveal details of their journey between the atmosphere and the sensors. By capturing a large number of muons passing through something, an image of it can be reconstructed.

“We successfully imaged the vertical profile of a cyclone, and this revealed density variations essential to understanding how cyclones work,” Tanaka said. “The images show cross-sections of the cyclone that passed through Kagoshima prefecture in western Japan. I was surprised to see clearly that it had a warm, low-density core that contrasted dramatically with the cold, high-pressure exterior. There is absolutely no way to capture such data with traditional pressure sensors and photography.”

The detector the researchers used has a 90-degree viewing angle, but Tanaka envisions combining similar sensors to create hemispherical, and thus omnidirectional, observing stations that could be placed along the coast. These could potentially see cyclones up to 300 kilometers away. Although satellites already track these storms, the additional detail it offers muography could improve predictions about approaching storms.

“One of the next steps for us now will be to refine this technique to detect and visualize storms at different scales,” Tanaka said. “This could mean better modeling and prediction not only for larger storm systems, but also for more local weather conditions.”

The article is published in ScientificReports.