In water, a whirlpool is a similar phenomenon. From Wikipedia, the free encyclopedia. For other uses, see Whirlwind disambiguation. This article does not cite any sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Cyclones and anticyclones of the world Centers of action.
Anticyclonic storm Storm High-pressure area Low-pressure area Rapid intensification Central dense overcast Annular tropical cyclone Bar tropical cyclone Superstorm Hypercane. North Polar low South Polar low. Extratropical cyclones. Alberta clipper Colorado low Great basin low. Panhandle hook Witch of November. European windstorms.
To make something or someone whirl. The dancer whirled his partner round on her toes. To remove or carry quickly with, or as with, a revolving motion; to snatch. Noun plural whirls An act of whirling. She gave the top a whirl and it spun across the floor. Something that whirls. A confused tumult. A rapid series of events My life is one social whirl. Out of the south cometh the whirlwind : and cold out of the north.
Cactus aficionados, don't get left in the dust with this quiz on desert plants. Find out if you have the knowledge to survive this prickly foray into the desert! This tall, horizontally branched cactus is probably the most recognizable cactus in Arizona. What is it called?
Dust devils form when a pocket of hot air near the surface rises quickly through cooler air above it, forming an updraft. If conditions are just right, the updraft may begin to rotate.
As the air rapidly rises, the column of hot air is stretched vertically, thereby moving mass closer to the axis of rotation, which causes intensification of the spinning effect by conservation of angular momentum. The secondary flow in the dust devil 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 upwards and in a circle. As the hot air rises, it cools, loses its buoyancy and eventually ceases to rise. As it rises, it displaces air which descends outside the core 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. As available 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 the dust devil is not moving fast enough depletion or begins to enter a terrain where the surface temperatures are cooler. Dust devils typically do not cause injuries, but rare, severe dust devils have caused damage and even deaths in the past.
One such dust devil struck the Coconino County Fairgrounds in Flagstaff, Arizona , on September 14, , causing extensive damage to several temporary tents, stands and booths, as well as some permanent fairgrounds structures.
Several injuries were reported, but there were no fatalities. No one was injured in the incident. Dust devils have been implicated in around aircraft accidents. Dust devils are also considered major hazards among skydivers and paragliding pilots as they can cause a parachute or a paraglider to collapse with little to no warning, at altitudes considered too low to cut away , and contribute to the serious injury or death of parachutists.
Dust devils, even small ones on Earth , can produce radio noise and electrical fields greater than 10, volts per meter. As the particles whirl around, they bump and scrape into each other and become electrically charged.
The whirling charged particles also create a magnetic field that fluctuates between 3 and 30 times each second. These electric fields may assist the vortices in lifting material off the ground and into the atmosphere. In comparison, the significantly smaller dust devils that twist across the deserts during the summer lift about three times as much dust, thus having a greater combined impact on the dust content of the atmosphere.
When this occurs, they are often called sand pillars. Dust devils also occur on Mars see dust devil tracks and were first photographed by the Viking orbiters in the s. In , the Mars Pathfinder lander detected a dust devil passing over it.
The dust devil itself the black spot is climbing the crater wall. The streaks on the right are sand dunes on the crater floor. Martian dust devils can be up to fifty times as wide and ten times as high as terrestrial dust devils, and large ones may pose a threat to terrestrial technology sent to Mars. Mission members monitoring the Spirit rover on Mars reported on March 12, , that a lucky encounter with a dust devil had cleaned the solar panels of that robot.Dust devil Formation. A dust devil in Ramadi, Iraq. Dust devils form when a pocket of hot air near the surface rises quickly Intensity and duration. On Earth, many dust devils are usually small and weak, often less than 3 feet ( m) in Hazards. Dust devils typically do not cause injuries.