Carme Farnell Burke At the Meteorological Office of Catalonia, Spain. “Wow! You can see inside the stone without breaking it. You could see the different layers with different densities.”
Hail during a severe storm that hit northeastern Spain in 2022 killed one child, injured dozens and caused millions of dollars worth of damage. The largest hailstone that fell was 12 centimeters in diameter, about twice the size of a tennis ball.
A few days after the storm, Farnell Burke and her colleagues went around asking if anyone had stored any hail. They collected 14 hailstones up to 8.5 centimeters in diameter that people had stored in plastic bags in the freezer.
Hailstones form when a layer of supercooled water accumulates on top of initial ice particles during a storm. The shape and density of these ice layers within the hailstones can reveal details about the growth process. But researchers are usually only able to study a few cross-sections of a single hailstone by cutting through the ice with a hot knife.
In this case, Farnell Burke’s orthodontist friend suggested the researchers use a CT scanner instead to reveal the complete internal structure of the calabash. And scanners were available at dental clinics.
The researchers scanned three pieces of hailstone, producing hundreds of cross-sections showing the variation in density within each ice flake. Some of the details were amazing. For example, hailstones were spherical, but their cores were located far from the center. Farnell-Burke said this suggests that the thickest part of the stone formed while it was falling, rather than as it was being cycled between different altitudes on the updrafts of the storm. states.
Julian Brimelow Canada's Northern Hale Project states: Several other small hailstones fell. Although scanned in this way, the stones from Spain are much larger. “This is important because it's still not clear where and how hail grows and reaches such impressive sizes in thunderstorms,” he says.
This increased understanding could improve predictions of hail size in future storms. “Each layer of growth can be correlated with radar data about the evolution of thunderstorms,” he says. Tomeu Rigo At the Catalan Meteorological Office. “Then we can correlate this with new thunderstorms and project the results into the future.”
“We'll probably have to look into this as to whether we're going to see more hail,” he said. john allen A professor at Central Michigan University is planning a large-scale hailstone mining expedition in the U.S. Great Plains in 2025. “The question is: how viable is this method for large quantities of stone?”
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Source: www.newscientist.com
