Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 20, 2000
Publication Date: September 20, 2000
Interpretive Summary: In arid or semiarid agricultural environments, dust storms are often associated with regional-scale wind erosion events. Regional dust emissions vary as atmospheric conditions and land-surface conditions change with the seasons. Taken together, atmospheric conditions and land-surface conditions form the governing environmental conditions which control the frequency and intensity of regional dust storms. Specific environmental conditions include negligible surface cover, low surface soil moisture, lack of precipitation, low humidity, and strong winds. In most cases, the exact influence of each factor on regional dust levels is still imperfectly understood and less is understood about the combined effects of multiple environmental factors. Here an attempt is made to quantify the influence of environmental factors such as surface cover, humidity, precipitation, and wind speed on measured regional dust concentrations in the Southern High Plains of North America.
Technical Abstract: Continuous measurements of dust reveal the intermittent nature of extreme dust events within the Southern High Plains of North America. Dust events appear as sudden peaks that project outward from a much lower background dust concentration. The measured dust record appears to follow a regular annual cycle with most extreme events occurring in spring and considerably fewer during other seasons. The annual dust cycle reflects seasonal changes in environmental factors such as wind speed, surface cover, and moisture conditions. Most extreme dust events are associated with a combination of strong winds, negligible surface cover, and dry conditions, all of which occur most frequently during the spring season. Wind speed alone is found to be an imperfect indicator of dust levels in the Southern High Plains because of the moderating effects of other important environmental factors such as humidity and surface cover. However, if one limits consideration to dry and bare conditions, PM10 concentration exhibits a strong correlation with daily wind speeds above 4 m/s and a negligible correlation for light winds.