Spinning up a dust devil in the thin air of Mars requires a stronger updraft than is needed to create a similar vortex on Earth, according to research at The University of Alabama in Huntsville (UAH).
Early results from this research in UAH's Atmospheric Science Department are scheduled for presentation today at the American Geophysical Union's fall meeting in San Francisco.
"To start a dust devil on Mars you need convection, a strong updraft," said Bryce Williams, an atmospheric science graduate student at UAH. "We looked at the ratio between convection and surface turbulence to find the sweet spot where there is enough updraft to overcome the low level wind and turbulence. And on Mars, where we think the process that creates a vortex is more easily disrupted by frictional dissipation – turbulence and wind at the surface – you need twice as much convective updraft as you do on Earth."