Desert Dust in the Atmosphere

by

Natalie M. Mahowald

• LAST REVIEWED: 24 May 2021
• LAST MODIFIED: 31 August 2015
• DOI: 10.1093/obo/9780199363445-0032

Introduction

Desert dust represents one of the largest sources of aerosols to the atmosphere in terms of mass (see also Atmospheric Composition and Structure). Desert dust particles are mineral soil particles suspended in the atmosphere from dry and unvegetated regions during high-wind events (see also Arid Environments). These particles are transported with the winds and can last in the atmosphere from minutes to weeks, depending on their size, with smaller particles lasting longer. The chemical composition of desert dust can be highly heterogeneous. Desert dust events can last short time periods (~1 day), and the frequency of these events can be highly variable in both space and time. The highest desert dust concentrations are thought to occur in the desert regions of North Africa and Asia. Dust can also vary on longer time scales, such as glacial-interglacial variability, with changes in concentration or deposition flux of a factor of 10–100 on a regional basis, or almost a factor of 3 globally averaged. While in the atmosphere, desert dust particles interact directly with radiation in both the long and short wave, as well as with both liquid and ice clouds to indirectly impact the radiation. Desert dust carries important micronutrients, such as iron and phosphorus, and thus once deposited on the surface can modify ocean and land biogeochemistry. Deposited desert dust particles can also modify snow albedo.

General Overviews

There are several recent papers that provide an overview of atmospheric desert dust and associated processes. Washington and Wiggs 2011 covers the many dimensions of the desert dust question focusing on the source areas. Long-range transport and deposition to the oceans is reviewed in Schulz, et al. 2012, while Shao, et al. 2011 reviews our understanding of dust within the context of the earth system. Mahowald, et al. 2013 focuses on the importance of the size of dust on both transport and depositional processes and on the impacts of dust onto the earth system. Aeolian Research is a journal focusing on Aeolian processes. Pye 1987 is a book focused on dust generation and depositional processes close to the source areas, while Seinfeld and Pandis 1998 is a book with excellent chapters focusing on aerosol dynamics in the atmosphere. Goudie and Middleton 2006 is a book outlining the sources and variability in desert dust, as well as the impacts on ecosystems and humans.

• Aeolian Research. 2009–.

  Journal focused on Aeolian processes, such as desert dust generation, which includes many review articles as well as field and modeling studies.

• Goudie, A., and N. Middleton. 2006. Desert dust in the global system. Heidelberg, Germany: Springer.

  Book which is a good review of desert dust entrainment, sources of variability, and impacts on humans and ecosystems.

• Mahowald, N., S. Albani, J. Kok, et al. 2013. The size distribution of desert dust aerosols and its impact on the Earth system. Aeolian Research

  Review of our understanding of desert dust size and its importance for the impacts of dust onto the climate system.

• Pye, K. 1987. Aeolian dust and dust deposits. London: Academic.

  Classic book focusing on dust generation, depositional processes near source areas.

• Schulz, M., J. Prospero, A. Baker, et al. 2012. The atmospheric transport and deposition of mineral aerosols to the ocean: Implications for research needs. Environmental Science and Technology 46:10390–10404.

  DOI: 10.1021/es300073u

  Review paper identifying the main barriers to improving our understanding of links between desert dust generation and deposition to oceans.

• Seinfeld, J., and S. Pandis. 1998. Atmospheric chemistry and physics. New York: John Wiley.

  A book on atmospheric chemistry; the chapters on aerosol dynamics are an excellent introduction to the material.

• Shao, Y., K.-H. Wyrwoll, A. Chappel, et al. 2011. Dust cycle: An emerging core theme in earth system science. Aeolian Research 2.4: 181–204.

  DOI: 10.1016/j.aeolia.2011.02.001

  Review of the role of desert dust with the Earth system.

• Washington, R., and G. Wiggs. 2011. Desert dust. In Arid zone geomorphology: Process, form and change in drylands. Edited by D. Thomas, 517–537. Chichester, UK: John Wiley.

  DOI: 10.1002/9780470710777

  Recent review of our understanding of desert dust, with a focus on source regions.