Climatic Change

, Volume 5, Issue 4, pp 365–380 | Cite as

On the desertification of the Sahel zone

Part 1: Ground observations
  • G. Wendler
  • F. Eaton


Ground based measurements which were carried out in the Northern Sahel in southern Tunisia showed the following results:
  1. (a)

    The albedo difference between ground and protected land is about 10%, half of the amount Charney (1975) used in his model.

  2. (b)

    Bare soil is always warmer during times of bright sunshine than vegetated soil, which is in agreement with Jackson and Idso (1975). Temperature differences in excess of the 10 °C were observed between plants and the surrounding soil.

  3. (c)

    For bare soil, the surface temperature increases with declining albedo. However the opposite holds true for plants. Here, when lowering the albedo, a decrease in temperature was found.

  4. (d)

    In a sand dune field, the surface temperature depends strongly on the exposure. Surface temperature differences of 8 °C were observed for slopes of different exposures for measurements carried out around noon.



Surface Temperature Temperature Increase Temperature Difference Sand Dune Bare Soil 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Ångström, A.: 1916, ‘Über die Gegenstrahlung der Atmosphäre’,Met. Z. 33, 529–538.Google Scholar
  2. Berkofsky, L.: 1976, ‘The Effect of Variable Surface Albedo on the Atmospheric Circulation in Desert Regions’,Journal of Applied Meteorology 1139–1144.Google Scholar
  3. Bolz and Falckenberg, G.: 1949, ‘Neubestimmung der Konstanten der Angströmischen Strahlungs-Formel’,Z. f. Met. 3, 97–100.Google Scholar
  4. Charney, J.: 1975, ‘Dynamics of Deserts and Drought in the Sahel’,Quart. J. R. Met. Soc. 101, 193- 202.CrossRefGoogle Scholar
  5. Charney, J., Stone, P. H., and Quirk, W. J.: 1975, ‘Drought in the Sahara: A Biogeophysical Feedback Mechanism’,Science 187, 434–435.Google Scholar
  6. Charney, J., Stone, P. H. and Quirk, W. J.: 1976, ‘Reply to E.A. Ripley’,Science 191, 100–102.Google Scholar
  7. Dirmhirn, I.: 1967,On the Applicability of Silicon Cells in Atmospheric Radiation Studies, Report for Contract NASA-NGR-06–002–038. US. Government Printing Office, Washington, D.C.Google Scholar
  8. Dirmhirn, I. and Eaton, F.: 1978, ‘Airborne Infrared Measurements of Logan Canyon, Utah’,Fourth Symposium on Meteorological Observations and Instrumentation, April 10–14, Denver, Colorado, 1979.Google Scholar
  9. Eaton, F. D. and Dirmhirn, I.: 1979, ‘Reflected Irradiance Indicatrices of Natural Surfaces and their Effect on Albedo’,Applied Optics 18, 994–1008.CrossRefGoogle Scholar
  10. Ellsaesser, H. W., MacCracken, M. C., Potter, G. L., and Luther, F. M.: 1976, ‘An Additional Model Test of Positive Feedback from High Desert Albedo’,Quart. J. R. Met. Soc. 102, 655–666.CrossRefGoogle Scholar
  11. Flohn, H. and Ketala, M.: 1970,Etude des Conditions Climatiques de l'avance due Desert, WMO Technical Notes, No. 116, WMO No. 279.Google Scholar
  12. Flohn, H., Saharization: 1971,Natural Causes or Management? WMO - Special Environm Report No. 2 WMO No. 312, 101–106.Google Scholar
  13. Flohn, H.: 1977,Climate Fluctuations in the Arid Belt of the Old World since 10 000 BP: Possible Causes and Future Implications, Conference on Meteorology of Semi-arid Areas, Tel Aviv.Google Scholar
  14. Flohn, H., Henning, D., and Korff, H. Cl.: 1974, ‘Possibilities and Limitations of a Large-Scale Water Budget Modification in the Sudan-Sahel Belt of Afrika’,Meteor. Rundsch. 27, 97–100.Google Scholar
  15. Flowers, E.: 1979,NOAA Calibration Center Operations. 1st DOE Environmental Resource Assessments Branch Quarterly Contractors Program Reviews.Google Scholar
  16. Geiger, R.: 1975,The Climate Near the Ground, Harvard University Press. Cambridge Mass. 611.Google Scholar
  17. Hare, F.: 1976,Climate and Desertification. Report Prepared for the United Nations Environment Programme. Univ. of Toronto, Inst. for Envir. Studies.Google Scholar
  18. Idso, S. B.: 1977, ‘A Note on Some Recently Proposed Mechanisms of Genesis of Deserts’,Quart. J. R. Met. Soc. 103, 369–370.CrossRefGoogle Scholar
  19. Jackson, R. D. and Idso, S. B.: 1975, ‘Surface Albedo and Desertification’,Science 189, 1012–1013.Google Scholar
  20. Joseph, J. H.: 1977,The Effect of a Desert Aerosol in a Model of the General Circulation (Keynote Paper), Proceedings of the Symposium on Radiation in the Atmosphere, 487–492.Google Scholar
  21. List, R. J.: 1968,Smithsonian Meteorological Tables, Vol. 114, 6th Edition Smithsonian Institution Press: Washington D.C.Google Scholar
  22. Novikoff, G., Wagner, F. H., and Hajjaj, M. S.: 1977,Systems Analysis of the Presaharan Ecosystem of Southern Tunisia, Desert Biome Report No. 6.Google Scholar
  23. Ohring, G. and Gyoeri, S.: 1977, ‘Some Experiments with a Zonally Averaged Climate Model’,Proceedings of the Symposium on Radiation in the Atmosphere, 493–495.Google Scholar
  24. Otterman, J.: 1974, ‘Baring High-Albedo Soils by Overgrazing: A Hypothesized Desertification Mechanism’,Science 186, 531–533Google Scholar
  25. Otterman, J.: 1981, ‘Satellite and Field Studies of Man's Impact on the Surface in Arid Regions’,Tellus 33, 68–77.CrossRefGoogle Scholar
  26. Otterman, J. and Tucker, C. J.: 1982, ‘Satellite Monitoring of Surface Temperatures in Semi-Desert: Differences between Anthropogenically Impacted Terrain and Protected Natural Vegetation’, (draft) Invited Paper 10.2.6.Advances in Space Research.Google Scholar
  27. Rasool, S. I., Courel, M. F., Kandel, R., and Habif, M.: 1982, ‘Satellite Investigations of Surface Cover Changes in Sahel during the Last Decade’,Proceedings of COSPAR, Ottawa.Google Scholar
  28. Ripley, E. A.: 1976, ‘Drought in the Sahara: Insufficient Biogeophysical Feedback?’Science 191, 100.Google Scholar
  29. Walker, J. M. and Rowntree, P. R.: 1977, ‘The Effect of Soil Moisture on Circulation and Rainfall in a Tropical Model’,Quart. J. R. Met. Soc. 103, 29–46.CrossRefGoogle Scholar
  30. Wendler, G. and Streten, N. A.: 1969, ‘A Short Term Heat Balance Study on a Coast Range Glacier’,Pure and Applied Geophysics 77, 68–77.CrossRefGoogle Scholar

Copyright information

© D. Reidel Publishing Company 1983

Authors and Affiliations

  • G. Wendler
    • 1
  • F. Eaton
    • 1
  1. 1.Geophysical InstituteUniversity of AlaskaFairbanksUSA

Personalised recommendations