from the space-for-improvement dept.
Stanford scientists solve mystery of icy plumes that may foretell deadly supercell storms
The most devastating tornadoes are often preceded by a cloudy plume of ice and water vapor billowing above a severe thunderstorm. New research reveals the mechanism for these plumes could be tied to "hydraulic jumps" – a phenomenon Leonardo Da Vinci observed more than 500 years ago.
When a cloudy plume of ice and water vapor billows up above the top of a severe thunderstorm, there's a good chance a violent tornado, high winds or hailstones bigger than golf balls will soon pelt the Earth below.
A new Stanford University-led study, published Sept. 10 in Science, reveals the physical mechanism for these plumes, which form above most of the world's most damaging tornadoes.
[...] Understanding how and why plumes take shape above powerful thunderstorms could help forecasters recognize similar impending dangers and issue more accurate warnings without relying on Doppler radar systems, which can be knocked out by wind and hail – and have blind spots even on good days. In many parts of the world, Doppler radar coverage is nonexistent.
"If there's going to be a terrible hurricane, we can see it from space. We can't see tornadoes because they're hidden below thunderstorm tops. We need to understand the tops better," said O'Neill, who is an assistant professor of Earth system science at Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth).
1.) Morgan E O’Neill, Leigh Orf, Gerald M. Heymsfield, et al. Hydraulic jump dynamics above supercell thunderstorms, Science (DOI: 10.1126/science.abh3857)
2.) Ivan Marusic, Susan Broomhall. Leonardo da Vinci and Fluid Mechanics [open], Annual Review of Fluid Mechanics (DOI: 10.1146/annurev-fluid-022620-122816)