Dust Storms: A Dusty Story
Teagan Calahan, Undergraduate Geographer/EIUWC Weather Analyst/WEIU Skywatch Forecaster
January 20, 2012
Weather is an ever changing thing that happens all over the globe. In certain areas of the world there are different, rare phenomena that occur; one of these phenomena is dust storms. When a person hears the word ‘dust’ it is easy to assume that these happen only in deserts or in certain parts of the world, this simply is not true. While dust storms often to take place in deserts, they can also occur in arid regions, or regions that have seen recent drought. Places that see these dust storms the most include the Sahara Desert in African, Australia, the Middle East, and right here in the United States (usually in Arizona).
Dust storms occur when loose dirt, soil, or sand is picked up by a strong wind that forces the small particles up in the air. At the same time that these particles are being lifted in to the air, some are being blown back down to the earth which causes more and more particles to vibrate and become loose creating somewhat of a domino effect, until you have a dust storm. Most storms that occur typically only last a few minutes to a few hours depending on the severity of the storm. They are truly something to see though since an impending storm looks like a solid wall that can be miles long and thousands of feet high like in figure one.
An important aspect of a dust storm is the wind that creates it. To create a storm of this proportion, obviously your daily breeze will not do the trick. One main way that strong enough winds develop is when there is a strong pressure gradient, or in other words, how close a high pressure is to a low pressure; the closer a high pressure system gets to a low pressure system, the stronger the winds are. Another common way for strong winds to happen in an area is when a strong cold front comes through that does not being any kind of precipitation with it. The last way that strong winds may be created is from the down drafts of a thunderstorm.
Dust storms can travel for miles, especially storms that come from the Sahara Desert. Figure two shows a satellite picture of a storm that is making its way across Morocco into the Atlantic Ocean. Strong storms like this are also thought to carry certain air-borne diseases across the globe.
Although dust storms may not be something that we think about very often here in the United States, it is important to remember that in our past, we had one dust storm that lasted not minutes, not hours, but years! The Dust Bowl happened in the Great Plains in the 1930’s. Starting in 1932 there were several dust storms caused by a combination of drought and poor farming techniques. The result was many people either pushed from their homes, forced to live else ware, as well as death from people suffocating because of all the dust that was constantly in the air and in their home.
These storms may not be something that we experience every day, but they are a force to be reckoned with. Pictures of dust storms may be stunning but then are very dangerous and are not something to be taken lightly.
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Figure 1. Dust storm in Arizona. Photo by NWS Phoenix. |
Figure 2. Dust storm as viewed from satellites. Photo by NOAA. |
