Abstract
The Infra-Red Difference Dust Index (IDDI) is a new dataset that uses reductions in atmospheric brightness temperature (derived from METEOSAT IR-channel measurements) to map the distribution of mineral aerosols over continental Africa. The IDDI dataset is described, and the IDDI data are used to identify the major African dust sources, located in the Sahel-Sahara zone. The seasonal variations in these sources are discussed. Annual, seasonal and monthly dust indices are constructed from the IDDI data for different latitudinal zones in the Sahel-Sahara zone. The temporal and spatial variability of dust production in the Sahel and Sahara is inferred from these indices and the latitudes of maximum dust production are identified. Interannual variability of dust production is described in conjunction with a consideration of variations in annual rainfall over the Sahel. Relationships between rainfall and subsequent dust production in the Sahel are investigated by correlating zonally averaged rainfall and IDDI values at lags of one and two years.
The spatial and temporal patterns of dust production suggest that spring and summer deflation is associated with the passage of convective disturbances across the Sahel. There is evidence that wet-season rainfall totals have an impact on dust production in the later part of the following dry season. The results also suggest a cumulative impact of rainfall on December dust production. However, there is no evidence from this study that dust production is associated with widespread land degradation.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Adeyfa, Z. D. and Holmgren, B. (1996) Spectral solar irradiance before and during a Harmattan dust spell, Solar Energy 57 (3), 195–203.
Arino O., Melinotte, J-M. Rosaz, J. M. and Monjoux, E. (1997) ESA Fire Product, Proceedings of the 7th ISPRS conference on Physical Measurement and Signatures in Remote Sensing, 7–11 April, Courchevel.
Arino O. and Melinotte, J-M. (1995) Fire Index Atlas, Earth Observation Quarterly 50, T.D. Guyenne (ed.), ESA Publications Division, ESA/ESTEC, Keplerplaan 12200 AG, Noordwijk, The Netherlands.
Artaxo, P., Gerab, F., Yamasoe, M. A. and Martins, J. V. (1994) Fine mode aerosols compositions at 3 long-term atmospheric monitoring sites in the Amazon Basin, Journal of Geophysical Research — Atmospheres 99 D11, 22857–22868.
Baird, A. J. (1997) Overland flow generation and sediment mobilisation by water, in Thomas, D. S. G. (Ed.) Arid zone geomorphology: Process, form and change in drylands, 2nd Edition, John Wiley and Sons Ltd, 165–184.
Barrey, R. G. and Chorley, R. J. (1995) Atmosphere, weather and Climate, 6th Edition, Routledge, p. 259.
Bullard, J. E. (1997) Vegetation and geomorphology, in Thomas, D. S. G. (Ed.) Arid zone geomorphology: Process, form and change in drylands, 2nd Edition, John Wiley and Sons Ltd, 109–131.
Chiapello, I., Bergametti, G., Gomes, L., Chatenet, B., Dulac, F., Pimenta, J., Santos Suares, E. (1995). An additional low layer transport of Sahelian and Saharan dust over the North-Eastern Tropical Atlantic, Geophysical Research Letters 22, 3191–3194.
Coudé-Gaussen, G., Rognon, P., Bergametti, G., Gomes, L., Strauss, B, Gros, J. M., Le Coustumer, M. N. (1987) Saharan dust on Fuertaventura Island: Chemical and mineralogical characteristics, air mass trajectories, and probable sources, Journal of Geophysical Research 92, 9753–9771.
Drees, L. R., Manu, A. and Wilding, L. P. (1993) Characteristics of aeolian dusts in Niger, West Africa, Geoderma 59, 213–233.
Dubief, J. (1979) Review of the North African climate with particular emphasis on the production of eolian dust in the Sahel zone and in the Sahara, in Morales, C. (Ed.) Saharan Dust, John Wiley and Sons Ltd.
Hastenrath, S. (1991) Climate Dynamics of the Tropics, Kluwer Academic Publishers, Dordrecht.
Hess, T., Stephens, W. and Thomas, G. (1996) Modelling NDVI from decadal rainfall data in the north east arid zone of Nigeria, Journal of Environmental Management 48, 249–261.
Husar, R. B., Prospero, J. M. and Stowe, L. L. (1997) Characterisation of tropospheric aerosols over the oceans with the NOAA advanced very high resolution radiometer optical thickness operational product, Journal of Geophysical Research 102 D14, 16, 889–16909.
Kalu, A. E. (1979) The African dust plume: its characteristics and propagation across West Africa in winter, in Saharan Dust: mobilisation, transport, deposition: papers and recommendations from a workshop held in Gothenburg, Sweden, 25–28 April 1977, C. Morales (ed.), Wiley.
Lamb, P. J., Bell, M. A. Finch J. D. (1998) Variability of Sahelian disturbance lines and rainfall during 1951 – 1987, Water Resources Variability in Africa during the XXth Century (Proceedings of the Abidjan ’98 Conference held at Abidjan, Côte d’Ivoire, November 1998). IAHS Publications No. 252.
Legrand, M., Nüoume, C. and Jankowiak, I. (1994) Satellite-derived climatology of the Saharan aerosol, Passive Infrared remote sensing of clouds and the atmosphere II, D. K. Lynch (ed.), Proc. SPIE 2309, 127–135.
McTainsh, G. H. (1980) Harmattan dust deposition in northern Nigeria, Nature 286, 587–588.
McTainsh, G. (1996) Dust concentrations and particle-size characteristics of an intense dust haze event: inland delta region, Mali, West Africa, Atmospheric Environment 30, 1081–1090.
Maley, J. (1982) Dust, clouds, rain types, and climatic variations in tropical North Africa, Quaternary Research 18, 1–16.
Middleton, N. J. (1985) Effect of drought on dust production in the Sahel, Nature 316, 431–434.
Middleton, N. J. (1997) Desert dust, in Thomas, D. S. G. (Ed.) Arid Zone Geomorphology, Wiley.
New, M. G., Hulme, M. and Jones, P. D. (1999) Representing 20th century space-time climate variability. II: Development of a 1901–1996 monthly terrestrial climate fields, Journal of Climate, in press.
N’Tchayi, G. M., Bertrand, J., Legrand, M. and Baudet, J. (1994) Temporal and spatial variations of the atmospheric dust loading throughout West Africa over the last thirty years, Annales Geophysicae 12, 265–273.
N’Tchayi Mbourou, G., Bertrand, J. J., Nicholson, S. (1997) The diurnal and seasonal cycles of wind-borne dust over Africa north of the equator, Journal of Applied Meteorology 36, 868–882.
Prospero, J. M. and Nees, R. T. (1986) The Impact of the North African Drought and El-Nino on Mineral Dust in the Barbados Trade Winds, Nature 320, 735–738.
Reiff, J., Forbes, S., Spieksma, T.Th. M., Reynders, J. J. (1986) African dust reaching northwestern Europe: A case study to verify trajectory calculations, Journal of Climate and Applied Meteorology 25, 1543–1567.
Rowell, D. P. and Milford, J. R. (1993) On the generation of African squall lines, Journal of Climate 6, 1181–1193.
Sirocko, F., Sarnthein, M., Lange, H. and Erlenkeuser, H. (1991) Atmospheric summer circulation and coastal upwelling in the Arabian Sea during the Holocene and the last Glaciation, Quaternary Research 36, 72–93.
Tegen, I. and Fung, I. (1995) Contribution to the atmospheric mineral aerosol load from land surface modification, Journal of Geophysical Research, 100, 18, 707–18, 726.
Tegen, I., Lacis, A. A. and Fung, I. (1996) The influence on climate forcing of mineral aerosols from disturbed soils, Nature 380, 419–422.
Tetzlaff, G. and Peters, M. (1988) A composite study of early summer squall lines and their environment over West Africa, Meteorology and Atmospheric Physics 38, 153–163.
UNEP (1992) World Atlas of Desertification, N. Middleton and D. S. G. Thomas (Eds.), Edward Arnold, London.
Warren, A. (1996) Desertification, in Adams, W. M., Goudie, A. S. and Orme, A. R. (Eds.) The Physical Geography of Africa, pp 343–355.
Williams, M. A. J. and Balling, R. C. (1996) Interactions of Desertification and Climate, WMO, UNEP, Arnold, London, pp 25–28.
WMO (1976) Special environmental report No. 9: An evaluation of climate and water resources for development of agriculture in the Sudano-Sahelian zone of West Africa, WMO — No. 459.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2000 Kluwer Academic Publishers
About this chapter
Cite this chapter
Brooks, N., Legrand, M. (2000). Dust Variability over Northern Africa and Rainfall in the Sahel. In: McLaren, S.J., Kniveton, D.R. (eds) Linking Climate Change to Land Surface Change. Advances in Global Change Research, vol 6. Springer, Dordrecht. https://doi.org/10.1007/0-306-48086-7_1
Download citation
DOI: https://doi.org/10.1007/0-306-48086-7_1
Publisher Name: Springer, Dordrecht
Print ISBN: 978-90-481-5589-7
Online ISBN: 978-0-306-48086-7
eBook Packages: Springer Book Archive