Letter | Published:

The past, present and future of African dust

Nature volume 531, pages 493495 (24 March 2016) | Download Citation


African dust emission and transport exhibits variability on diurnal1 to decadal2 timescales and is known to influence processes such as Amazon productivity3, Atlantic climate modes4, regional atmospheric composition and radiative balance5 and precipitation in the Sahel6. To elucidate the role of African dust in the climate system, it is necessary to understand the factors governing its emission and transport. However, African dust is correlated with seemingly disparate atmospheric phenomena, including the El Niño/Southern Oscillation7,8, the North Atlantic Oscillation9, the meridional position of the intertropical convergence zone10,11, Sahelian rainfall8 and surface temperatures over the Sahara Desert12, all of which obfuscate the connection between dust and climate. Here we show that the surface wind field responsible for most of the variability in North African dust emission reflects the topography of the Sahara, owing to orographic acceleration of the surface flow. As such, the correlations between dust and various climate phenomena probably arise from the projection of the winds associated with these phenomena onto an orographically controlled pattern of wind variability. A 161-year time series of dust from 1851 to 2011, created by projecting this wind field pattern onto surface winds from a historical reanalysis13, suggests that the highest concentrations of dust occurred from the 1910s to the 1940s and the 1970s to the 1980s, and that there have been three periods of persistent anomalously low dust concentrations—in the 1860s, 1950s and 2000s. Projections of the wind pattern onto climate models give a statistically significant downward trend in African dust emission and transport as greenhouse gas concentrations increase over the twenty-first century, potentially associated with a slow-down of the tropical circulation. Such a dust feedback, which is not represented in climate models, may be of benefit to human and ecosystem health in West Africa via improved air quality14 and increased rainfall6. This feedback may also enhance warming of the tropical North Atlantic15, which would make the basin more suitable for hurricane formation and growth16.

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  1. 1.

    , & Diurnal cycle of dust and cirrus over West Africa as seen from Meteosat Second Generation satellite and a regional forecast model. Geophys. Res. Lett. 34, L02822 (2007)

  2. 2.

    & African dust over the northern tropical Atlantic: 1955–2008. J. Appl. Meteorol. Climatol. 49, 2213–2229 (2010)

  3. 3.

    , & Fertilizing the Amazon and equatorial Atlantic with West African dust. Geophys. Res. Lett. 37, L14807 (2010)

  4. 4.

    , , & Influence of African dust on ocean-atmosphere variability in the tropical Atlantic. Nature Geosci. 4, 762–765 (2011)

  5. 5.

    , & What controls the recent changes in African mineral dust aerosol across the Atlantic? Atmos. Chem. Phys. 14, 5735–5747 (2014)

  6. 6.

    et al. Impact of desert dust radiative forcing on Sahel precipitation: relative importance of dust compared to sea surface temperature variations, vegetation changes, and greenhouse gas warming. J. Clim. 20, 1445–1467 (2007)

  7. 7.

    et al. Interannual modulation of subtropical Atlantic boreal summer dust variability by ENSO. Clim. Dyn. 46, 585–599 (2015)

  8. 8.

    & African droughts and dust transport to the Caribbean: climate change implications. Science 302, 1024–1027 (2003)

  9. 9.

    et al. Control of atmospheric export of dust from North Africa by the North Atlantic Oscillation. Nature 287, 691–694 (1997)

  10. 10.

    , & Control of Saharan mineral dust transport to Barbados in winter by the Intertropical Convergence Zone over West Africa. J. Geophys. Res. 117, D19117 (2012)

  11. 11.

    , & Role of the convergence zone over West Africa in controlling Saharan mineral dust load and transport in the boreal summer. Tellus B 66, 23191 (2014)

  12. 12.

    , , & On the decadal scale correlation between African dust and Sahel rainfall: the role of Saharan heat low-forced winds. Science Adv. 1, e1500646 (2015)

  13. 13.

    et al. The twentieth century reanalysis project. Q. J. R. Meteorol. Soc. 137, 1–28 (2011)

  14. 14.

    & Dust storms and their impact on ocean and human health: dust in Earth’s atmosphere. EcoHealth 1, 284–295 (2004)

  15. 15.

    , , , & The role of aerosols in the evolution of tropical North Atlantic ocean temperature anomalies. Science 324, 778–781 (2009)

  16. 16.

    & The impact of the Saharan air layer on Atlantic tropical cyclone activity. Bull. Am. Meteorol. Soc. 85, 353–365 (2004)

  17. 17.

    et al. The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q. J. R. Meteorol. Soc. 137, 553–597 (2011)

  18. 18.

    et al. Links between topography, wind, deflation, lakes and dust: the case of the Bodélé depression, Chad. Geophys. Res. Lett. 33, L09401 (2006)

  19. 19.

    , , , & Environmental characterization of global sources of atmospheric soil dust identified with the Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) absorbing aerosol product. Rev. Geophys. 40, 1002 (2002)

  20. 20.

    et al. Derivation of an observation-based map of North African dust emission. Aeolian Res. 16, 153–162 (2015)

  21. 21.

    et al. The twentieth century reanalysis project. Q. J. R. Meteorol. Soc. 137, 1–28 (2011)

  22. 22.

    , , & An analysis of aeolian dust in climate models. Geophys. Res. Lett. 41, 5996–6001 (2014)

  23. 23.

    , & An overview of CMIP5 and the experiment design. Bull. Am. Meteorol. Soc. 93, 485–498 (2012)

  24. 24.

    & Robust responses of the hydrological cycle to global warming. J. Clim. 19, 5686–5699 (2006)

  25. 25.

    et al. Explosive growth in African combustion emissions from 2005 to 2030. Environ. Res. Lett. 9, 035003 (2014)

  26. 26.

    & Identification of a new dust-stratocumulus indirect effect over the tropical North Atlantic. Geophys. Res. Lett. 41, 6935–6942 (2014)

  27. 27.

    Increasing destructiveness of tropical cyclones over the past 30 years. Nature 436, 686–688 (2005)

  28. 28.

    & Effect of remote sea surface temperature change on tropical cyclone potential intensity. Nature 450, 1066–1070 (2007)

  29. 29.

    & A more general framework for understanding Atlantic hurricane variability and trends. Bull. Am. Meteorol. Soc. 88, 1767–1781 (2007)

  30. 30.

    et al. Can we use surface wind fields from meteorological reanalyses for Sahelian dust emission simulations? Geophys. Res. Lett. 42, 2490–2499 (2015)

  31. 31.

    , , , & Toward a consistent reanalysis of the climate system. Bull. Am. Meteorol. Soc. 95, 1235–1248 (2014)

  32. 32.

    et al. MERRA: NASA’s modern-era retrospective analysis for research and applications. J. Clim. 24, 3624–3648 (2011)

  33. 33.

    et al. NCEP-DOE AMIP-II reanalysis (R-2). Bull. Am. Meteorol. Soc. 83, 1631–1643 (2002)

  34. 34.

    et al. The NCEP/NCAR 40-year reanalysis project. Bull. Am. Meteorol. Soc. 77, 437–471 (1996)

  35. 35.

    & Modeling the atmospheric dust cycle: 1. Design of a soil-derived dust emission scheme. J. Geophys. Res. 100, 16415–16430 (1995)

  36. 36.

    , , , & The importance of the representation of deep convection for modeled dust-generating winds over West Africa during summer. Geophys. Res. Lett. 38, L16803 (2011)

  37. 37.

    , & Are vegetation-related roughness changes the cause of the recent decrease in dust emission from the Sahel? Geophys. Res. Lett. 40, 1868–1872 (2013)

  38. 38.

    , & A two-dimensional numerical investigation of the dynamics and microphysics of Saharan dust storms. J. Geophys. Res. 92, 3027–3049 (1987)

  39. 39.

    & Modeling of mineral dust in the atmosphere: sources, transport, and optical thickness. J. Geophys. Res. 99, 22897–22914 (1994)

  40. 40.

    , & Parameterization of the increase of the aeolian erosion threshold wind friction velocity due to soil moisture for arid and semi-arid areas. Ann. Geophys. 17, 149–157 (1999)

  41. 41.

    , , , & Dust and the low-level circulation over the Bodélé Depression, Chad: observations from BoDEx 2005. J. Geophys. Res. 111 (D3), D03201 (2006)

  42. 42.

    , & A global data set of Palmer Drought Severity Index for 1870-2002: relationship with soil moisture and effects of surface warming. J. Hydrometeorol. 5, 1117–1130 (2004)

  43. 43.

    et al. Observed 20th century desert dust variability: impact on climate and biogeochemistry. Atmos. Chem. Phys. 10, 10875–10893 (2010)

  44. 44.

    , & Extension to the North Atlantic Oscillation using early instrumental pressure observations from Gibraltar and South-West Iceland. Int. J. Climatol. 17, 1433–1450 (1997)

  45. 45.

    et al. Seasonal evolution of the West African heat low: a climatological perspective. Clim. Dyn. 33, 313–330 (2009)

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This work was supported by the Agence Nationale de la Recherche (ANR) grant ANR-10-LABX-18-01 of the national Programme Investissements d’Avenir provided by the Laboratoire d’excellence Institut Pierre Simon Laplace (L-IPSL). We appreciate comments from our colleagues.

Author information


  1. Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA

    • Amato T. Evan
  2. Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS)/IPSL, UPMC Université Paris 06, Sorbonne Université, UVSQ, CNRS, Paris, France

    • Amato T. Evan
    • , Cyrille Flamant
    •  & Marco Gaetani
  3. CNRM-GAME, UMR 3589 CNRS and Météo-France, Toulouse, France

    • Françoise Guichard


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A.T.E. carried out the main analysis and wrote the manuscript. F.G. analysed wind speed data from weather stations. All authors designed the study, discussed the results and commented on the manuscript.

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The authors declare no competing financial interests.

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Correspondence to Amato T. Evan.

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