ARS | Publication request: Assessing the dust generation potential of soils/sediments in Southern Kalahari.

Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: December 14, 2009
Publication Date: December 17, 2009
Citation: Bhattachan, A., D'Odorico, P., Zobeck, T.M., Okin, G. 2009. Assessing the dust generation potential of soils/sediments in Southern Kalahari[abstract]. American Geophysical Union. December 14-17, 2009. San Francisco, California.

Technical Abstract: The Kalahari encompasses one of the largest drylands and sand seas in the southern hemisphere, and has potential to become a large source of atmospheric dust in the relatively low-dust southern hemisphere. It has been observed that in the southern Kalahari dunes are being reactivated as a result of the loss of vegetation cover induced by the decrease in mean annual precipitation, and land use practices such as grazing, and farming. Therefore, aridification, combined with land use, will result in remobilization of sand dunes that are currently stabilized by savanna and rangeland vegetation. It is not clear whether the remobilization of these aeolian deposits will be able to generate dust-sized soil particles and contribute to atmospheric dust emissions. While a number of studies have addressed the importance of mineral aerosols in global climate dynamics, biogeochemical cycles, and human health, little has been done to locate - particularly in the southern hemisphere - possible new dust sources that could be activated as a result of climate or land use (e.g., grazing or fire regime) change. In this study we investigate the properties of Kalahari sands and pan deposits to assess whether dune remobilization in the Kalahari could lead to the activation of a major dust source in the southern hemisphere. Because at present most of the dust sources on Earth are in the northern hemisphere and western Africa, this new dust source could have an important impact on the atmospheric composition and biogeochemistry of the entire southern hemisphere.