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Advances in Meteorology
Volume 2014, Article ID 405617, 12 pages
http://dx.doi.org/10.1155/2014/405617
Research Article

Characterization of West African Jet Streams and Their Association to ENSO Events and Rainfall in ERA-Interim 1979–2011

Beltsville Center for Climate System Observation, Atmospheric Science Program, Howard University, Washington DC, DC 20059, USA

Received 15 November 2013; Revised 9 January 2014; Accepted 10 January 2014; Published 5 March 2014

Academic Editor: Sven-Erik Gryning

Copyright © 2014 Churchill Okonkwo 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. A. Giannini, R. Saravanan, and P. Chang, “Oceanic forcing of Sahel rainfall on interannual to interdecadal time scales,” Science, vol. 302, no. 5647, pp. 1027–1030, 2003. View at Publisher · View at Google Scholar · View at Scopus
  2. C. M. Taylor, E. F. Lambin, N. Stephenne, R. J. Harding, and R. L. H. Essery, “The influence of land use change on climate in the Sahel,” Journal of Climate, vol. 15, no. 24, pp. 3615–3629, 2002. View at Google Scholar · View at Scopus
  3. J. G. Charney, “Dynamics of deserts and drought in the Sahel,” Quarterly Journal of Royal Meteorological Society, vol. 101, no. 428, pp. 193–202, 1975. View at Publisher · View at Google Scholar
  4. Y. X. Yongkang Xue and J. Shukla, “The influence of land surface properties on Sahel climate. Part I: desertification,” Journal of Climate, vol. 6, no. 12, pp. 2232–2245, 1993. View at Google Scholar · View at Scopus
  5. K. Y. Li, M. T. Coe, N. Ramankutty, and R. D. Jong, “Modeling the hydrological impact of land-use change in West Africa,” Journal of Hydrology, vol. 337, no. 3-4, pp. 258–268, 2007. View at Publisher · View at Google Scholar · View at Scopus
  6. J. F. Reynolds and D. M. Stafford, Do Humans Cause Deserts? Global Desertification: Do Humans Cause Deserts, 2002.
  7. L. Eklundh and L. Olsson, “Vegetation index trends for the African Sahel 1982–1999,” Geophysical Research Letters, vol. 30, no. 8, 2003. View at Publisher · View at Google Scholar · View at Scopus
  8. L. Polgreen, “In Niger, trees and crops turn back the desert,” New York Times, February 2007.
  9. S. M. Herrmann, A. Anyamba, and C. J. Tucker, “Recent trends in vegetation dynamics in the African Sahel and their relationship to climate,” Global Environmental Change, vol. 15, no. 4, pp. 394–404, 2005. View at Publisher · View at Google Scholar · View at Scopus
  10. M. Biasutti, I. M. Held, A. H. Sobel, and A. Giannini, “SST forcings and Sahel rainfall variability in simulations of the twentieth and twenty-first centuries,” Journal of Climate, vol. 21, no. 14, pp. 3471–3486, 2008. View at Publisher · View at Google Scholar · View at Scopus
  11. A. Giannini, R. Saravanan, and P. Chang, “Dynamics of the borealsummer African monsoon in the NSIPP1 atmospheric model,” Climate Dynamics, vol. 25, no. 5, pp. 517–535, 2005. View at Publisher · View at Google Scholar
  12. A. Giannini, M. Biasutti, and M. M. Verstraete, “A climate model-based review of drought in the Sahel: desertification, the re-greening and climate change,” Global and Planetary Change, vol. 64, no. 3-4, pp. 119–128, 2008. View at Publisher · View at Google Scholar · View at Scopus
  13. S. E. Nicholson, “The West African Sahel: a review of recent studies on the rainfall regime and its interannual variability,” ISRN Meteorology, vol. 2013, Article ID 453521, 32 pages, 2013. View at Publisher · View at Google Scholar
  14. C. K. Folland, T. N. Palmer, and D. E. Parker, “Sahel rainfall and worldwide sea temperatures, 1901–85,” Nature, vol. 320, no. 6063, pp. 602–607, 1986. View at Google Scholar · View at Scopus
  15. J. Lu and T. L. Delworth, “Oceanic forcing of the late 20th century Sahel drought,” Geophysical Research Letters, vol. 32, no. 22, Article ID L22706, pp. 1–5, 2005. View at Publisher · View at Google Scholar · View at Scopus
  16. M. Hoerling, J. Hurrell, J. Eischeid, and A. Phillips, “Detection and attribution of twentieth-century northern and southern African rainfall change,” Journal of Climate, vol. 19, no. 16, pp. 3989–4008, 2006. View at Publisher · View at Google Scholar · View at Scopus
  17. I. Polo, A. Ullmann, P. Roucou, and B. Fontaine, “Weather regimes in the Euro-Atlantic and Mediterranean sector, and relationship with West African rainfall over the 1989–2008 period from a self-organizing maps approach,” Journal of Climate, vol. 24, no. 13, pp. 3423–3432, 2011. View at Publisher · View at Google Scholar · View at Scopus
  18. I. Polo, B. Rodríguez-Fonseca, T. Losada, and J. García-Serrano, “Tropical atlantic variability modes (1979–2002). Part I: time-evolving SST modes related to West African rainfall,” Journal of Climate, vol. 21, no. 24, pp. 6457–6475, 2008. View at Publisher · View at Google Scholar · View at Scopus
  19. C. E. Chung and V. Ramanathan, “Weakening of north Indian SST gradients and the monsoon rainfall in India and the Sahel,” Journal of Climate, vol. 19, no. 10, pp. 2036–2045, 2006. View at Publisher · View at Google Scholar · View at Scopus
  20. D. P. Rowell, “Teleconnections between the tropical Pacific and the Sahel,” Quarterly Journal of the Royal Meteorological Society, vol. 127, no. 575, pp. 1683–1706, 2001. View at Publisher · View at Google Scholar · View at Scopus
  21. C. Caminade and L. Terray, “Twentieth century sahel rainfall variability as simulated by the ARPEGE AGCM, and future changes,” Climate Dynamics, vol. 35, no. 1, pp. 75–94, 2010. View at Publisher · View at Google Scholar · View at Scopus
  22. M. Joly, A. Voldoire, H. Douville, P. Terray, and J.-F. Royer, “African monsoon teleconnections with tropical SSTs: validation and evolution in a set of IPCC4 simulations,” Climate Dynamics, vol. 29, no. 1, pp. 1–20, 2007. View at Publisher · View at Google Scholar · View at Scopus
  23. L. M. Druyan, “Studies of 21st-century precipitation trends over West Africa,” International Journal of Climatology, vol. 31, no. 10, pp. 1415–1424, 2011. View at Publisher · View at Google Scholar · View at Scopus
  24. S. E. Nicholson, “On the factors modulating the intensity of the tropical rainbelt over West Africa,” International Journal of Climatology, vol. 29, no. 5, pp. 673–689, 2009. View at Publisher · View at Google Scholar · View at Scopus
  25. R. Zhang and T. L. Delworth, “Impact of Atlantic multidecadal oscillations on India/Sahel rainfall and Atlantic hurricanes,” Geophysical Research Letters, vol. 33, no. 17, Article ID L17712, 2006. View at Publisher · View at Google Scholar · View at Scopus
  26. C. D. Thorncroft, H. Nguyen, C. Zhang, and P. Peyrille, “Annual cycle of the West African monsoon: regional circulations and associated water vapour transport,” Quarterly Journal of the Royal Meteorological Society, vol. 137, no. 654, pp. 129–147, 2011. View at Publisher · View at Google Scholar · View at Scopus
  27. J. H. Christensen, T. R. Carter, M. Rummukainen, and G. Amanatidis, “Evaluating the performance and utility of regional climate models: the PRUDENCE project,” Climatic Change, vol. 81, no. 1, pp. 1–6, 2007. View at Publisher · View at Google Scholar · View at Scopus
  28. J. F. Griffiths, Climate of Africa, vol. 10 of World Survey of Climatology, Elsevier, 1972.
  29. S.-Y. Wang and R. R. Gillies, “Observed change in Sahel rainfall, circulations, African easterly waves, and Atlantic hurricanes since 1979,” International Journal of Geophysics, vol. 2011, Article ID 259529, 14 pages, 2011. View at Publisher · View at Google Scholar
  30. A. Simmons, S. Uppala, D. Dee, and S. Kobayashi, “ERA-Interim: new ECMWF reanalysis products from 1989 onwards,” ECMWF Newsletter, vol. 110, no. 110, pp. 25–35, 2007. View at Google Scholar
  31. D. P. Dee, S. M. Uppala, A. J. Simmons et al., “The ERA-Interim reanalysis: configuration and performance of the data assimilation system,” Quarterly Journal of the Royal Meteorological Society, vol. 137, no. 656, pp. 553–597, 2011. View at Publisher · View at Google Scholar · View at Scopus
  32. J.-N. Thépaut, “Assimilating only surface pressure observations in 3D and 4DVar,” in Proceedings of the ECMWF Workshop on Atmospheric Reanalysis, pp. 107–112, ECMWF, Reading, UK, June 2006.
  33. J. S. Whitaker, G. P. Compo, and J.-N. Thépaut, “A comparison of variational and ensemble-based data assimilation systems for reanalysis of sparse observations,” Monthly Weather Review, vol. 137, no. 6, pp. 1991–1999, 2009. View at Publisher · View at Google Scholar · View at Scopus
  34. J. E. Janowiak, A. Gruber, C. R. Kondragunta, R. E. Livezey, and G. J. Huffman, “A comparison of the NCEP-NCAR reanalysis precipitation and the GPCP rain gauge-satellite combined dataset with observational error considerations,” Journal of Climate, vol. 11, no. 11, pp. 2960–2979, 1998. View at Google Scholar · View at Scopus
  35. X.-Z. Liang and W.-C. Wang, “Associations between China monsoon rainfall and tropospheric jets,” Quarterly Journal of the Royal Meteorological Society, vol. 124, no. 552, pp. 2597–2623, 1998. View at Google Scholar · View at Scopus
  36. 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. View at Google Scholar · View at Scopus
  37. A. Grinsted, J. C. Moore, and S. Jevrejeva, “Application of the cross wavelet transform and wavelet coherence to geophysical times series,” Nonlinear Processes in Geophysics, vol. 11, no. 5-6, pp. 561–566, 2004. View at Google Scholar · View at Scopus
  38. C. Kidd, E. Dawkins, and G. Huffman, “Comparison of precipitation derived from the ECMWF operational forecast model and satellite precipitation data sets,” Journal of Hydrometeorology, vol. 14, pp. 1463–1482, 2013. View at Publisher · View at Google Scholar
  39. N. M. J. Hall, G. N. Kiladis, and C. D. Thorncroft, “Three-dimensional structure and dynamics of African easterly waves. Part II: dynamical modes,” Journal of the Atmospheric Sciences, vol. 63, no. 9, pp. 2231–2245, 2006. View at Publisher · View at Google Scholar · View at Scopus
  40. A. K. Dezfuli and S. E. Nicholson, “A note on long-term variations of the African easterly jet,” International Journal of Climatology, vol. 31, no. 13, pp. 2049–2054, 2011. View at Publisher · View at Google Scholar · View at Scopus
  41. J. P. Grist and E. Nicholson, “A study of the dynamic factors influencing the rainfall variability in the West African Sahel,” Journal of Climate, vol. 14, no. 7, pp. 1337–1359, 2001. View at Google Scholar · View at Scopus
  42. B. Pu and K. H. Cook, “Dynamics of the West African westerly jet,” Journal of Climate, vol. 23, no. 23, pp. 6263–6276, 2010. View at Publisher · View at Google Scholar · View at Scopus
  43. J.-B. Stuut, M. Zabel, V. Ratmeyer et al., “Provenance of present-day eolian dust collected off NW Africa,” Journal of Geophysical Research D, vol. 110, no. 4, Article ID D04202, pp. 1–14, 2005. View at Publisher · View at Google Scholar · View at Scopus
  44. E. A. Afiesimama, “Annual cycle of the mid-tropospheric easterly jet over West Africa,” Theoretical and Applied Climatology, vol. 90, no. 1-2, pp. 103–111, 2007. View at Publisher · View at Google Scholar · View at Scopus
  45. S. E. Nicholson and J. P. Grist, “The seasonal evolution of the atmospheric circulation over West Africa and equatorial Africa,” Journal of Climate, vol. 16, no. 7, pp. 1013–1030, 2003. View at Google Scholar
  46. T.-C. Chen, “Maintenance of the midtropospheric North African summer circulation; Saharan high and African easterly jet,” Journal of Climate, vol. 18, no. 15, pp. 2943–2962, 2005. View at Publisher · View at Google Scholar · View at Scopus
  47. R. J. Cornforth, B. J. Hoskins, and C. D. Thorncroft, “The impact of moist processes on the African Easterly Jet-African Easterly Wave system,” Quarterly Journal of the Royal Meteorological Society, vol. 135, no. 641, pp. 894–913, 2009. View at Publisher · View at Google Scholar · View at Scopus
  48. T. C. Chen and H. van Loon, “Interannual variation of the tropical easterly jet,” Monthly Weather Review, vol. 115, no. 8, pp. 1739–1759, 1987. View at Google Scholar · View at Scopus
  49. S. Janicot and B. Sultan, “Intra-seasonal modulation of convection in the West African monsoon,” Geophysical Research Letters, vol. 28, no. 3, pp. 523–526, 2001. View at Publisher · View at Google Scholar · View at Scopus
  50. T. Losada, B. Rodríguez-Fonseca, E. Mohino, J. Bader, S. Janicot, and C. R. Mechoso, “Tropical SST and Sahel rainfall: a non-stationary relationship,” Geophysical Research Letters, vol. 39, Article ID L12705, 2012. View at Google Scholar
  51. S.-I. An and B. Wang, “The forced and intrinsic low-frequency modes in the North Pacific,” Journal of Climate, vol. 18, no. 6, pp. 876–885, 2005. View at Publisher · View at Google Scholar · View at Scopus