Long-range transport of mineral dust in the global atmosphere: Impact of African dust on the environment of the southeastern United States

Abstract

Soil dust is a major constituent of airborne particles in the global atmosphere. Dust plumes frequently cover huge areas of the earth; they are one of the most prominent and commonly visible features in satellite imagery. Dust is believed to play a role in many biogeochemical processes, but the importance of dust in these processes is not well understood because of the dearth of information about the global distribution of dust and its physical, chemical, and mineralogical properties. This paper describes some features of the large-scale distribution of dust and identifies some of the geological characteristics of important source areas. The transport of dust from North Africa is presented as an example of possible long-range dust effects, and the impact of African dust on environmental processes in the western North Atlantic and the southeastern United States is assessed. Dust transported over long distances usually has a mass median diameter <10 m. Small wind-borne soil particles show signs of extensive weathering; consequently, the physical and chemical properties of the particles will greatly depend on the weathering history in the source region and on the subsequent modifications that occur during transit in the atmosphere (typically a period of a week or more). To fully understand the role of dust in the environment and in human health, mineralogists will have to work closely with scientists in other disciplines to characterize the properties of mineral particles as an ensemble and as individual particles especially with regard to surface characteristics.

Atmospheric P deposition to the subtropical North Atlantic: sources, properties, and relationship to N deposition

“…Barbados receives about 2.5 times more dust annually than Miami owing to higher dust concentrations and a longer dust transport season [Prospero, 1999]. However, the multiday time scale (n) of dust episodes and aerosol distributions gathered from remote sensors indicate that dust aerosol composition is similar in both Miami and Barbados [Trapp et al, 2010a], as well as the rest of the western subtropical region [Prospero, 1999]. Sea spray is another common aerosol source in both sites.…”

“…In contrast, in Miami local and regional pollution can impact our samples all year round because of land-sea breeze effects. Pollution aerosols are particularly common during the winter when wind patterns periodically shift in conjunction with coldfront passages so that Miami receives northerly air masses [Prospero, 1999;Prospero et al, 2010].…”

“…[9] For both sites, mineral dust is the primary source of aerosols during the summer [Li et al, 1996;Prospero and Lamb, 2003;Prospero, 1999]. Barbados receives about 2.5 times more dust annually than Miami owing to higher dust concentrations and a longer dust transport season [Prospero, 1999].…”

Effect of vegetation coverage on aeolian dust accumulation in a semiarid steppe of northern China

“…On a global scale, a region or one major ecosystem type can be a large "dust collector"; the positive or negative effects of dust collection determine whether an ecosystem is a dust source or sink and can also directly reflect the loss and accumulation of soil resources. Therefore, it has been suggested that dust plays an important role in many biogeochemical processes (Prospero, 1999;Muhs et al, 2008).…”

Enhancing dust storm detection using PCA based data fusion

“…Dust storms are a significant air pollution contributor impacting urban areas as well as a health hazard for people with respiratory problems [1], [2]. Hence, timely warnings of dust storms must be initiated in populated regions for health concerns and traffic control.…”