Summary
Meteorological conditions associated with the transport and deposition of harmattan dust particles in West Africa are discussed as well as particle-size distribution analyses of Saharan aeolian dust monitored at Ile-Ife (7.29 N, 4.34 E) nearly 2,000 km South-West of its predominant source region, the Chad Basin.
Mineralogical analysis of the dust indicated that it is predominantly composed of quartz (> 70%) followed by microcline, kaolinite and traces of mica and halloysite. Chemical analyses indicated a predominance of SiO2 (> 60%) followed by Al2O3 (17.4%), Na2O (10.1%), Fe203 (5.6%), TiO2 (3.33%), K2O (1.88%), MgO (0.56%), and CaO (0.37%). The following trace elements were identified: Zn (931 ppm), Mn (834 ppm), Ni (113 ppm), Cr (103 ppm), Cu (106 ppm), Co (77 ppm) V (65 ppm) and Li (25 ppm).
The effect of the poor visibility caused by the harmattan dust on aviation operation and safety as well as the health hazards posed on the respiratory system by the air-borne toxic elements should be of concern to relevant decision makers and should be further investigated.
Zusammenfassung
Vorliegende Studie behandelt meteorologische Bedingungen in Zusammenhang mit dem Transport und der Ablagerung von Harmattan-Staubpartikeln in Westafrika, als auch Partikelgrößenverteilungen, die in Ile-Ife (7.29N, 4.34E) aufgezeichnet wurden, beinahe 2000 km südwestlich von ihrer wichtigsten Ursprungsregion, dem Tschad-Becken.
Die mineralogische Analyse des Staubes hat gezeigt, daß er im wesentlichen aus Quartz (> 70%) besteht. Chemische Analysen des Staubes wiesen hauptsächlich SiO2 (> 60%), sowie Al2O3 (17,4%), Na2O (10,1%), Fe2O3 (5,6%) TiO2 (3,33%), K2O (1,88%), MgO (0,56%) und CaO (0.37%) aus; an Spurenelementen wurden Zn (931 ppm), Mn (834 ppm), Ni (113 ppm), Cr (103 ppm), Cu (106 ppm), Co (77 ppm), V (65 ppm) und Li (25 ppm) nachgewiesen.
Die Auswirkungen der durch den Harmattan-Staub stark geminderten Sichtweite auf den Flugverkehr und dessen Sicherheit sowie die gesundheitliche Beeinträchtigung der Atemwege durch giftige Aerosole sollten Gegenstand der Sorge staatstragender Kräfte als auch weiterer Forschungsbemühungen sein!
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References
Adebayo, S. I., 1980: Pronounced Dust Haze Spell Over Nigeria, 2–11 March, 1971. In: Pre-WAMEX Symp., Adefolalu (ed) Lagos, Nigeria: Leo Printers, 270–300.
Adedokun J. A., 1978: West African precipitation and dominant atmospheric mechanisms.Arch. Met. Geoph. Biokl., Ser. A 27 289–310.
Adedokun, J. A., Adeyefa, Z. D., 1988: Preliminary measurements of direct solar radiation over Ile-Ife, Nigeria (under preparation).
Adefolalu, D. O., 1984: On bioclimatological aspects of Harmattan dust haze in Nigeria.Arch. Met. Geoph. Biocl. Ser. B 33 387–404.
Ademuwagun, E. A., 1984: Dust particles size distribution in the atmosphere during harmattan at Ife. Unpublished B.Sc. Thesis, Physics Department, Obafemi Awolowo University, Ile-Ife, Nigeria.
Adetunji, J., McGregor, J., Ong, C. K., 1979: Harmattan haze.Weather 34 430–436.
Adetunji, J., Ong, C. K., 1980: Qualitative analysis of the Harmattan haze by X-ray diffraction.Atmos. Environ 14 857–859.
Aina, J. A., 1972: A contribution to the forecasting of Harmattan dust haze.Nig. Quart. Met. Mag. 2 77–90.
Akeredolu, F. A., 1986: Indoor/Outdoor levels of particulates in Ile-Ife, Nigeria. Clean Air Congress 1986. Sydney, Australia 25–29 Aug. 1986 (Hartmann H. F., ed) ISB No. 0–959 9002-8-4, 155–167.
Bagnold, R. A., 1971:The Physics of Blown Sand and Desert Dunes. Frome and London: Chapman & Hall. 265 pp.
Balogun, E. E., 1974: The phenomenology of the atmosphere over West Africa. Proceedings of Ghana Scope's Conference on Environment and Development in West Africa. Ghana Acad. of Arts and Sciences, 19–31.
Bigglestone, H. J., 1958: Diurnal variations in surface wind speed at Kano. British West Africa Met. Serv. Techn. Note No. 8., Nig. Met. Services, Lagos, Nigeria.
Brinkman, A. W., McGregor, J., 1983: Solar radiation in dense Saharan aerosol in Northern Nigeria.Quart. J. Roy. Meteor. Soc. 109 831–847.
Brown, G., (ed) 1951):The X-Ray Identification and Crustal Structures of Clay Materials. Min. Soc. Lond. 489–516.
Carrol, D., 1970: Clay minerals: a guide to their X-Ray identification. Geol. Soc. Am. Special Paper 126, 75 pp.
Emofurieta, W. O., 1987: The geochemical, mineralogical and economic potentials of a tropical residual soil profile in SW-Nigeria.Journ. Sc., 21, (in press).
Gillete, D., 1980: Major contributions of natural primary continental aerosols: Source mechanisms. Annals of the New York Academy of Sciences, Vol. 338, 348–358
Hamilton, R. A., Archbold, J. W., 1945: Meteorology of Nigeria and adjacent territory.Quart J. Roy. Meteor. Soc. 71 231–265
JCPDS, 1980:Mineral Powder Diffraction File Vols I & II. Pub. Intern. Centre for Diffraction Data, Park Lane U.S.A., Vol. 1 (1168 pp.), Vol. II (484 pp.).
Kalu, A. E., 1977: The African dust plume: Its characteristics and propagation across West Africa in Winter. In: Saharan Dust (Morales, ed.) New York, Wiley, Ch. 5, 95–118.
Ludlam, F. H., 1980:Clouds and Storms. University Park & London: Pennsylvania State University Press, 407 pp.
Makanjuola, A. A., Beetlestone, J. G., 1975: Some chemical and mineralogical notes on Kaun (Trona),Journ. Nig. Min. Geol. & Meta. Soc. 10 31–41.
McTainsh, G. H., Walker, P. H., 1982: Nature and Distribution of Harmattan Dust.Z. Geomorph. N. F. 26 417–435
Morales, C., (ed) 1977: Saharan Dust: Mobilization, Transport, Deposition; SCOPE/The Ecological Research Committee of NFP. Stockholm, Sweden, 297 pp.
Samways, J., 1975: A synoptic account of an occurrence of dense Harmattan Dust in Kano in Feb. 1974.Savanna 4 187–190.
Shutz, L., 1980: Long range transport of desert dust with special emphasis on the Sahara.Annals of the New York Academy of Sciences 338 515–532.
Shutz, L., Jaenicke, R., Pietrek, H. 1981: Saharan dust transport over the North Atlantic Ocean. Geological Society of America, Special Paper186 87–100.
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Adedokun, J.A., Emofurieta, W.O. & Adedeji, O.A. Physical, mineralogical and chemical properties of harmattan dust at Ile-Ife, Nigeria. Theor Appl Climatol 40, 161–169 (1989). https://doi.org/10.1007/BF00866179
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DOI: https://doi.org/10.1007/BF00866179