There are five main types of whirlwinds that are created by atmospheric weather conditions and also with the aid of the radiation of our Sun. For our purpose, a whirlwind is defined as a rotating and cone shaped air mass above the surface of the Earth. The most common of which is known to us as a tornado. So too, hurricanes, cyclones, water spouts, and dust devils are also whirlwinds. Dust devils and water spouts are formed by rising hot air and those other whirlwinds are formed by colder sinking air.
However, unlike a tornado, a dust devil is created by means of a different method that still produces the same result. In that, a dust devil appears to be a tornado and, in fact, can be as large and as powerful as a tornado. Than again, no other whirlwinds are as large or as powerful as hurricanes or cyclones. Those hurricanes and cyclones are the Mothers of all whirlwinds, so to speak.
Briefly, a dust devil is usually created within desert and semi-arid plains regions during what would be considered to be a calm day but also a hot day, weather wise. Heat is generated by the radiation from the Sun causing the air near the surface of the land to become overheated, in relation to the air temperature of the air that is higher above the ground.
That overheated air near the surface then rises and mixes with the cooler air. That process causes a localized rotation of the air as it rises, which then forms a coned shaped and whirling air mass. Additional air from its base is then sucked up and into the structure, together with dirt, sand and other matter. Dust devils can last for only a few seconds after being created or they can last for as long as several hours and be blown a long distance across the landscape by the prevailing wind.
As a matter of fact, those solid particles of whatever is sucked into dust devil highlights the shape and the size of the dust devil, just as such debris and water vapor renders visible a tornado. During my lifetime I saw many dust devils but they proved to be harmless to me and my property. Then again, maybe I was just one of the lucky ones who witnessed such events and lived to tell about it.
For your additional information, water spouts are created in the same manner as dust devils, the difference being that a water spout is created just above the surface of a body of water. Yes and even small fish are drawn into those water spouts and are occasionally dropped on to the land.
The wonders and mysteries of our natural environment never cease to amaze me and I never tire of seeing such events. That includes those truly mysterious and at times invisible whirlwinds.
