About this Journal Submit a Manuscript Table of Contents
International Journal of Geophysics
Volume 2011 (2011), Article ID 874292, 14 pages
http://dx.doi.org/10.1155/2011/874292
Research Article

African Easterly Waves and Cyclonic Activity over the Eastern Atlantic: Composite and Case Studies

1Laboratoire d'Océanographie, des Sciences de l'Environnement et du Climat (LOSEC), Université de Ziguinchor, BP 523, Ziguinchor, Senegal
2IRD-LTHE, Université de Grenoble, BP 53, 38041 Grenoble Cedex 9, France
3LPAO-SF, ESP-UCAD, BP 5085, Dakar-Fann, Senegal

Received 25 February 2011; Revised 17 July 2011; Accepted 20 August 2011

Academic Editor: Gregory S. Jenkins

Copyright © 2011 Moctar Camara et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Linked References

  1. W. M. Gray, “Global view of the origin of tropical disturbances and storms,” Monthly Weather Review, vol. 96, pp. 669–700, 1968.
  2. W. M. Gray, “Hurricanes: their formation, structure and likely role in the tropical circulation,” in Meteorology over the Tropical Oceans, D. B. Shaw, Ed., pp. 155–218, Royal Meteorological Society, Bracknall, UK, 1979.
  3. C. W. Landsea, “A climatology of intense (or major) Atlantic hurricanes,” Monthly Weather Review, vol. 121, no. 6, pp. 1703–1713, 1993.
  4. T. C. Chen, S. Y. Wang, and A. J. Clark, “North Atlantic hurricanes contributed by African esterly waves north and south of the African easterly jet,” Journal of Climate, vol. 21, no. 24, pp. 6767–6776, 2008. View at Publisher · View at Google Scholar
  5. R. S. Ross and T. N. Krishnamurti, “Low-level African easterly wave activity and its relation to Atlantic tropical cyclogenesis in 2001,” Monthly Weather Review, vol. 135, no. 12, pp. 3950–3964, 2007. View at Publisher · View at Google Scholar
  6. G. Berry, C. Thorncroft, and T. Hewson, “African easterly waves during 2004—analysis using objective techniques,” Monthly Weather Review, vol. 135, no. 4, pp. 1251–1267, 2007. View at Publisher · View at Google Scholar
  7. M. Camara, A. Diedhiou, and A. T. Gaye, “Spatial and temporal distribution of North Atlantic cyclones,” African Journal of Environmental Science and Technology, vol. 4, no. 1, pp. 477–483, 2010.
  8. R. W. Burpee, “The origin and structure of easterly waves in the lower troposphere of north Africa,” Journal of the Atmospheric Sciences, vol. 29, pp. 77–90, 1972.
  9. C. D. Thorncroft, N. M. J. Hall, and G. N. Kiladis, “Three-dimensional structure and dynamics of African easterly waves. Part III: genesis,” Journal of the Atmospheric Sciences, vol. 65, no. 11, pp. 3596–3607, 2008. View at Publisher · View at Google Scholar
  10. I. Pytharoulis and C. Thorncroft, “The low-level structure of African easterly waves in 1995,” Monthly Weather Review, vol. 127, no. 10, pp. 2266–2280, 1999.
  11. A. Diedhiou, S. Janicot, A. Viltard, P. De Felice, and H. Laurent, “Easterly wave regimes and associated convection over West Africa and tropical Atlantic: results from the NCEP/NCAR and ECMWF reanalyses,” Climate Dynamics, vol. 15, no. 11, pp. 795–822, 1999. View at Publisher · View at Google Scholar
  12. T. N. Carlson, “Some remarks on African disturbances and their progress,” Monthly Weather Review, vol. 97, pp. 716–728, 1969.
  13. G. Gu, R. F. Adler, G. J. Huffman, and S. Curtis, “African easterly waves and their association with precipitation,” Journal of Geophysical Research D: Atmospheres, vol. 109, no. 4, Article ID D04101, 12 pages, 2004. View at Publisher · View at Google Scholar
  14. A. Mekonnen, C. D. Thorncroft, and A. R. Aiyyer, “Analysis of convection and its association with African easterly waves,” Journal of Climate, vol. 19, no. 20, pp. 5405–5421, 2006. View at Publisher · View at Google Scholar
  15. J. M. Futyan and A. D. Del Genio, “Deep convetive system evolution over Africa and the tropical atlantic,” Journal of Climate, vol. 20, no. 20, pp. 5041–5060, 2007. View at Publisher · View at Google Scholar
  16. C. W. Landsea, G. D. Bell, W. M. Gray, and S. B. Goldenberg, “The extremely active 1995 Atlantic hurricane season: environmental conditions and verification of seasonal forecasts,” Monthly Weather Review, vol. 126, no. 5, pp. 1174–1193, 1998.
  17. S. B. Goldenberg, C. W. Landsea, A. M. Mestas-Nuñez, and W. M. Gray, “The recent increase in Atlantic hurricane activity: causes and implications,” Science, vol. 293, pp. 474–479, 2001.
  18. C. Thorncroft and K. Hodges, “African easterly wave variability and its relationship to Atlantic tropical cyclone activity,” Journal of Climate, vol. 14, no. 6, pp. 1166–1179, 2001.
  19. L. A. Avila and R. J. Pasch, “Atlantic tropical systems of 1991,” Monthly Weather Review, vol. 120, no. 11, pp. 2688–2696, 1992.
  20. R. J. Pasch, M. B. Lawrence, L. A. Avila, J. L. Beven, J. L. Franklin, and S. R. Stewart, “Atlantic hurricane season of 2002,” Monthly Weather Review, vol. 132, no. 7, pp. 1229–1289, 2004.
  21. L. A. Avila, R. J. Pasch, and J. G. Jiing, “Atlantic tropical systems of 1996 and 1997: years of contrasts,” Monthly Weather Review, vol. 128, no. 10, pp. 3695–3706, 2000.
  22. S. B. Hopsch, C. D. Thorncroft, and K. R. Tyle, “Analysis of African easterly wave structures and their role in influencing tropical cyclogenesis,” Monthly Weather Review, vol. 138, no. 4, pp. 1399–1419, 2010. View at Publisher · View at Google Scholar
  23. E. Kalnay, M. Kanamitsu, R. Kistler et al., “The NCEP/NCAR 40-year reanalysis project,” Bulletin of the American Meteorological Society, vol. 77, no. 3, pp. 437–471, 1996.
  24. A. F. Krueger and A. Grueber, “The status of NOAA Ougoing longwave radiation data set,” Bulletin of the American Meteorological Society, vol. 65, pp. 958–962, 1984.
  25. M. Farge, “Wavelet transforms and their applications to turbulence,” Annual Review of Fluid Mechanics, vol. 24, no. 1, pp. 395–457, 1992.
  26. C. Torrence and G. P. Compo, “A Practical Guide to Wavelet Analysis,” Bulletin of the American Meteorological Society, vol. 79, no. 1, pp. 61–78, 1998.
  27. C. D. Thorncroft and B. J. Hoskins, “An idealized study of African easterly waves. I: a linear view,” Quarterly Journal—Royal Meteorological Society, vol. 120, no. 518, pp. 953–982, 1994.
  28. M. Dickinson and J. Molinari, “Climatology of sign reversals of the meridional potential vorticity gradient over Africa and Australia,” Monthly Weather Review, vol. 128, no. 11, pp. 3890–3900, 2000.
  29. J. G. Charney and M. E. Stern, “On the stability of internal baroclinic jets in a rotating atmosphere,” Journal of the Atmospheric Sciences, vol. 19, pp. 159–172, 1962.
  30. K.-H. Lau and N.-C. Lau, “Observed structure and propagation characteristics of tropical summertime synoptic scale disturbances,” Monthly Weather Review, vol. 118, no. 9, pp. 1888–1913, 1990. View at Scopus
  31. D. C. Norquist, E. E. Recker, and R. J. Reed, “The energetics of African wave disturbances as observed during phase III of GATE,” Monthly Weather Review, vol. 105, pp. 334–342, 1977.
  32. C. D. Thorncroft and B. J. Hoskins, “An idealized study of African easterly waves. II: a nonlinear view,” Quartlery Journal—Royal Meteorological Society, vol. 120, no. 518, pp. 983–1015, 1994.
  33. J. Molinari, D. Knight, M. Dickinson, D. Vollaro, and S. Skubis, “Potential vorticity, easterly waves, and eastern Pacific tropical cyclogenesis,” Monthly Weather Review, vol. 125, no. 10, pp. 2699–2708, 1997.
  34. C. D. Thorncroft and M. Blackburn, “Maintenance of the African easterly jet,” Quarterly Journal of the Royal Meteorological Society, vol. 125, no. 555, pp. 763–786, 1999.
  35. W. M. Gray and C. W. Landsea, “African rainfall as a precursor of hurricane-related destruction on the US east coast,” Bulletin—American Meteorological Society, vol. 73, no. 9, pp. 1352–1364, 1992.
  36. J. P. Grist, S. E. Nicholson, and A. I. Barcilon, “Easterly waves over Africa. Part II: observed and modeled contrasts between wet and dry years,” Monthly Weather Review, vol. 130, no. 2, pp. 212–225, 2002.
  37. C. W. Landsea and W. M. Gray, “The strong association between Western Sahelian monsoon rainfall and intense Atlantic hurricanes,” Journal of Climate, vol. 5, pp. 435–453, 1992.
  38. K. A. Emanuel, “The finite-amplitude nature of tropical cyclogenesis,” Journal of the Atmospheric Sciences, vol. 46, no. 22, pp. 3431–3456, 1989.
  39. R. E. Newell and J. W. Kidson, “African mean wind changes between Sahelian wet and dry periods,” Journal of Climatology, vol. 4, no. 1, pp. 27–33, 1984.
  40. J. M. Prospero and T. N. Carlson, “Radon-222 in the North Atlantic trade winds: its relationship to dust transport from Africa,” Science, vol. 167, no. 3920, pp. 974–977, 1970.
  41. J. J. Walsh and K. A. Steidinger, “Saharan dust and Florida red tides: the cyanophyte connection,” Journal of Geophysical Research C: Oceans, vol. 106, no. 6, pp. 11597–11612, 2001.
  42. J. P. Dunion and C. S. Marron, “A reexamination of the Jordan mean tropical sounding based on awareness of the Saharan air layer: results from 2002,” Journal of Climate, vol. 21, no. 20, pp. 5242–5253, 2008. View at Publisher · View at Google Scholar
  43. S. B. Goldenberg and L. J. Shapiro, “Physical mechanisms for the association of El Niño and west African rainfall with Atlantic major hurricane activity,” Journal of Climate, vol. 9, no. 6, pp. 1169–1187, 1996.