What tempurature does it have to be when dust devils form?

Question

What tempurature does it have to be for dust devil formation 100-140?

Answer 1

Dust devils form when hot air near the surface rises quickly through a small pocket of cooler low pressure air above it. If conditions are just right, the air may begin to rotate. As the air rises suddenly, the column of hot air is stretched vertically causing intensification of the spinning effect by the scientific principle conservation of angular momentum. The spinning effect causes other hot air to speed horizontally inward to the bottom of the newly-forming vortex. As more hot air rushes in toward the developing vortex to replace the air that is rising, the spinning effect becomes further intensified and self-sustaining. A dust devil, fully formed, is a funnel-like chimney through which hot air moves both upwardly and circularly. Eventually the hot air will cool and descend back through the center of the vortex. This cool air returning acts as a balance against the spinning hot air outer wall and keeps the system stable.

The spinning effect, along with surface friction, usually will produce a forward momentum. The dust devil is able to sustain itself longer by moving over nearby sources of hot surface air. Dust particles sucked into the air will create drag and act to slow the system down.

As available extreme hot air near the surface is channeled up the dust devil, eventually surrounding cooler air will be sucked in. Once this occurs, the effect is dramatic and the dust devil dissipates in seconds. Usually this occurs when a dust devil isn't moving fast enough (depletion) or begins to enter a terrain where the surface temperatures are cooler, causing unbalance.

We have dust devils here in the Deep South US, too, and we usually have very humid conditions in spring and summer.

Answer 2

It must be hot and winds must be light. If a surface receives more heating as compared to surrounding surfaces, then conduction will result in buoyant air above the warmer surface. This buoyant air will rise quickly and begin spinning and so the dust devil is formed. So it just needs to be hot for dust devils to form.

Answer 3

Dust devils are basically mini tornadoes. I don't know if they form the same way, but I don't believe there has to be any specific temperature. For what it's worth, the rovers on Mars have seen dust devils on the Martian surface and I think the warmest it ever gets on Mars is about 40°F

Answer 4

any temperature a dust devil from from very,very weak ration in the atmosphere not by temperature

Answer 5

In Australia we call them "willy willlys". They are caused by differential heating of the air over a land surface. At one spot, for some reason, the air heats up faster then that around it. As you know, hot air rises. As this air rises the air around the hot air rushes in to take its place. Due to the Coreolous (sp) Effect, the direction of air flow is "bent" thus causing a circular flow of this air. Hope this helps.

Answer 6

it has to do with the wind not the temp. they happen in arizona(where I live) because its dry, because its hot, and the wind picks up the dust easy. but its about the dryness more than the hotness.