Dust-Storm Source Areas Determined by the Total Ozone Monitoring Spectrometer and Surface Observations

TLDR

Dust storms have wide environmental impacts, influence geomorphology through deflation and wind erosion, and represent a major source of atmospheric mineral dust that introduces significant uncertainty into climate models by affecting radiation budgets and atmospheric stability. The study aims to identify the principal dust source regions, particularly the Sahara, by integrating ground meteorological data, TOMS satellite observations, and NCEP–NCAR reanalysis, and to investigate reasons for discrepancies between satellite and surface observations. Eigenvector analysis of TOMS data was used to objectively delineate Sahara dust source regions. The analysis identified the Sahara as the dominant source and highlighted additional major dust sources in the Middle East, Taklamakan, southwest Asia, central Australia, southern African basins, Salar de Uyuni, and the Great Basin, with large internally drained basins acting as dust sources where favorable near‑surface circulation occurs, and noted that surface observations revealed important sources absent from TOMS maps.

Abstract

Abstract Dust storms are recognized as having a very wide range of environmental impacts. Their geomorphological interest lies in the amount of deflation and wind erosion they indicate and their role in loess formation. Atmospheric mineral-dust loading is one of the largest uncertainties in global climate-change modeling and is known to have an important impact on the radiation budget and atmospheric instability. Major gaps remain in our understanding of the geomorphological context of terrestrial sources and the transport mechanisms responsible for the production and distribution of atmospheric dust, all of which are important in reducing uncertainties in the modeling of past and future climate. Using meteorological data from ground stations, from the space-borne Total Ozone Monitoring Spectrometer (TOMS), and from the National Center for Environmental Prediction–National Center for Atmospheric Research reanalysis project, we illustrate the key source regions of dust and demonstrate the primacy of the Sahara. Objectively defined source regions for the Sahara are determined from eigenvector techniques applied to the TOMS data. Other key regions include the Middle East, Taklamakan, southwest Asia, central Australia, the Etosha and Mkgadikgadi basins of southern Africa, the Salar de Uyuni (Bolivia), and the Great Basin (United States). In most of these regions, large basins of internal drainage, as defined from a digital elevation model, are dust sources where the near-surface atmospheric circulation (determined by calculated means of potential sand flux) is favorable for dust mobilization. Surface observations indicate some regions as being important that do not appear on the TOMS maps. Possible reasons for these discrepancies are explored.