Dust storms have emerged as a pressing environmental issue affecting various regions worldwide, and the United States is no exception to this phenomenon. Characterized by strong winds picking up vast amounts of dust and sand, these storms pose significant challenges to ecosystems, agriculture, and public health. In addition, climate change threatens to worsen dust storms, as well as increase their frequency. Therefore, it is extremely important for individuals, businesses, and governments to better understand this extreme weather phenomenon, so that steps can be taken to better protect populations from the consequences they pose.
A dust storm is a meteorological phenomenon that occurs when strong winds lift vast amounts of dust into the air, allowing them to blanket areas spanning hundreds of miles. These storms can have varying durations, from a few minutes to several hours — depending on the intensity of the winds and the availability of loose particles on the ground for gusts to pick up. Dust storms' relative strength classifies them into three categories of storms: localized and channelized, gradient, and monsoonal convective. Localized dust storms form due to winds passing over disturbed areas and produce only small-scale dust. Gradient dust storms are produced by faster winds over large areas and create enough smog to create hazy air conditions. Monsoonal convective dust storms (also known as haboobs), occur when thunderstorm downdrafts hit the ground, creating enough energy to push dust thousands of meters into the air and create thick clouds spanning up to 160 kilometers.
Dust storms are prevalent in arid and semi-arid regions where loose soil and a lack of vegetation make it easier for wind to lift and transport particles. Formation begins with the dehydration of soil due to prolonged periods of drought-like conditions. As the soil dries out, it loses its cohesive properties, and becomes looser and therefore easier to dislodge. Human activities, such as overgrazing, deforestation, and inappropriate land use (which includes non-sustainable practices such as improper ploughing, inadequate management of plant residue, and over-pumping of groundwater) can also exacerbate soil degradation, leaving vast expanses of land vulnerable to wind erosion. When weather events bring in strong, gusty winds, they sweep across these barren landscapes, lifting the dry particles off the ground and carrying them up into the atmosphere. The airborne particles thus can create a haze that obscures visibility and transforms the sky into an eerie shade of brown or orange. In the case of haboobs, the front of the storm can appear as a colossal wall of dust, advancing rapidly across the landscape.
Though it experiences comparatively few dust storms versus African and Middle Eastern countries in close proximity to the Sahara Desert, the US has its fair share. Because dust storms need only loose soil and strong wind to form, they can occur anywhere. However, Southwestern states such as Arizona, New Mexico, and Texas, along with parts of California, are particularly prone to dust storms due to their widespread drier, desert-like landscapes. These areas experience dry conditions and loose soil, as well as having typically high atmospheric winds, a perfect combination for dust storm formation. Additionally, the Great Plains region, including states like Oklahoma, Kansas, and Colorado, is known as "Tornado Alley," and dust storms are a recurrent threat in this area due to its expansive flatlands and dry, exposed soil.
Dust storms have a profound impact on public health and quality of life. During these storms, particles are suspended in the air for long periods of time, leading to significantly reduced air quality. The inhalation of these particles, which can contain heavy metals and other toxins, may exacerbate respiratory conditions (such as asthma and bronchitis), lead to cardiovascular issues, and cause fungal infections. Vulnerable populations, such as children, the elderly, and individuals with pre-existing respiratory conditions, are particularly at risk. Additionally, the reduced visibility on roads during dust storms increases the risk of traffic accidents, posing challenges to transportation networks. Severe dust clouds can even ground air traffic and cause power outages. Moreover, damage to property, infrastructure, and agricultural lands is common during severe dust storms, resulting in economic losses for affected communities.
Climate change plays a significant role in exacerbating dust storms both in the US and around the world. Firstly, rising global temperatures contribute to more frequent and intense droughts, which create the dry conditions necessary for dust storm formation. Warmer temperatures in turn lead to higher rates of evaporation which dry out soil, making it more susceptible to wind erosion. More evaporation also means shrinking lakes in the Western US, which contributes to both the prevalence and danger of dust storms, as newly-exposed lakebeds are often laden with toxic material. Furthermore, changes in weather patterns induced by the shifting climate can alter wind patterns, increasing the likelihood of dust storms occurring. Deforestation and land degradation, often associated with climate change, also further contribute to soil erosion and the availability of loose particles for wind transport, leading to more frequent dust storms in various US regions, namely the Southwest.
On Monday, July 17, a dust storm rolled through downtown Phoenix, Arizona, bringing winds of 50-65 kilometers per hour and blanketing areas in the southern Maricopa and Pinal counties with dust. The dust storm, which was the first of its kind in the 2023 season, came about as a result of hail, heavy rain, and gusty winds produced by storms in Tucson in the late evening of the 17th, which scooped up and blew the dust Westward. Despite the impressive visual spectacle, according to weather service meteorologist Ryan Morley, the dust storm did not qualify as a haboob, because the visibility in Sky Harbor (the airport closest to downtown Phoenix) was reported at around 3.2 kilometers, which is over the quarter-mile threshold that constitutes a severe dust storm. However, some other areas reported local visibility between a quarter and half-mile, amounting to more serious conditions.
On Monday May 1, a severe dust storm originating from freshly tilled farm fields right outside of Springfield, Illinois, were scooped up by winds between 55-70 kph, reducing the visibility in the area to near zero. The severe conditions led to multiple crashes on highway I-55 involving 72 vehicles, and ultimately left at least seven dead and 37 injured. Traffic was shut down for over 50 kilometers in both directions. Officials noted that is was a localized event, and that the driving factor behind the sudden storm was merely the exposed, dirt farm fields nearby. Indeed, Illinois does not experience as many dust storms as other states in the Great Plains and southwestern regions of the US. However, drier and hotter conditions in farming communities are increasing their frequency, threatening significant consequences in the future.