Dust Devils!
Just what is a Dust Devil?
Dust devils are rotating columns of dust and air
that are common over many arid regions of Earth and
Mars. Although dust devils appear similar to tornados,
they are powered by a very different engine.
Cloud-free
skys and gentle breezes allow sunshine[1]
to warm the desert surface. The hot dust layer [2] then warms
the air immediately above it This ground air layer
becomes much hotter than the air only a few feet further
above the surface; creating an unstable local condition. Bubbles of hot air [3] then collect
and break free from the ground layer. A nudge from
a breeze is all it takes to initiate a twisting vortex
column, which in turn gathers more of the ground-level
hot air that sustains the process. A fast-spinning vortex becomes a dust devil once the
wind speeds are strong enough to lift the local dust.
For more information, visit: www.dustdevils.org
Dust Devil Images
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