Dust Devil in Monument Valley

I posted another photograph of this dust devil as it appeared to be traveling up a road in Monument Valley but I found this photograph of it that I had taken a little later and that I was able to process better to show the structure of the dust devil.

 

This dust devil formed as the sun heated the desert floor and it began to rise. A cooler layer on top of the warm air kept the entire column from rising until the buoyancy of the warm air broke through a warmer weak layer in the capping cold air. When this happened the warm air began to rush toward where the breakthrough occurred and the surface roughness and Coriolis effect began to force the inward rushing air to spin. Soon, the flow of air inward was strong enough to pick up the fine dust on the desert floor and a dust devil formed.

 

It looks like it was following the road but it actually was crossing over the road. The dust on the road, however, was picked up by the rotation and made the funnel more visible and distinct for a moment.

 

The capping layer was approximately as high as the buttes and you can see the funnel start to disperse in the more steady breeze above the buttes.

 

I noticed that two people at the bottom right of the photograph were standing, watching this dust devil cross the road.

 

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P.S.

I am always amazed how different things look depending on the background. Look at the dust devil against the sky: it looks very red while the same dust devil looks almost white against the red sandstone.

Done