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Swell description for Bonga offshore Nigeria location

  • Olugbenga, Akinsanya Akinyemi ;
  • Gudmestad, Ove Tobias ;
  • Agbakwuru, Jasper
  • Received : 2017.05.27
  • Accepted : 2017.11.07
  • Published : 2017.12.25

Abstract

The ocean environment offshore West Africa is considered to be mild. However, the generated swell from distant North and South Atlantic during austral winter and summer can reach high wave amplitudes with relatively low wave periods or low wave amplitudes with long wave periods, the later can be a crucial scenario to consider when the assessment of vessel resonance is of importance. Most offshore operations, which include offshore drilling, and installation in West Africa, are carried out from floating systems. The response of these systems and performance are governed by characteristics, such as amplitude and frequency of the wave and swell seas. It is therefore important to fully understand the sea conditions offshore Nigeria. This study covers the description of the swell sea offshore Nigeria using Bonga offshore wave measurements collected from the directional wave-rider (DWR), positioned at the Bonga site off the coast of Nigeria.

Keywords

West African swell waves;wave periods;wave heights;extreme value estimates;safe operations of floating vessels

References

  1. Alves, J.H.G.M. (2006), "Numerical modeling of ocean swell contributions to the global wind wave climate", Ocean Modell., 11(1-2), 98-122. https://doi.org/10.1016/j.ocemod.2004.11.007
  2. Ardhuin, F., Bertrand, C. and Fabrice, C. (2009), "Observation of swell dissipation across oceans", Geophys. Res. Lett., 39.
  3. Bhowmick, S., Kumar, R., Chaudhuri, S. and Sarkar, A. (2011), "Swell propagation over Indian Ocean Region", Int. J. Ocean Clim. Sys., 2, 87-99. https://doi.org/10.1260/1759-3131.2.2.87
  4. Bureau of Meteorology, Australian Govt. (2017), "'Second swell", http://www.bom.gov.au/marine/about/forecast/second-swell.shtml
  5. Ginos, B.F. (2009), "Parameter estimation for the lognormal distribution", Brigham Young University. Master of Science Thesis, Department of Statistics, Brigham Young University December.
  6. Chen, Y.H., Francis, J.A. and Miller, J.R. (2002), "Surface temperature of the arctic: Comparison of TOVS satellite retrievals with surface observations", J. Climate, 15, 10.1175/1520-0442, 3698-3708. https://doi.org/10.1175/1520-0442(2002)015<3698:STOTAC>2.0.CO;2
  7. DNV-RP-H103. (2011), "Modelling and analysis of marine operations, recommended practice", Last Modified April.https://rules.dnvgl.com/docs/pdf/DNV/codes/docs/2012-12/RP-H103.pdf.
  8. Ewans, K., Forristall, G.Z., Olagnon, M., Prevosto, M. and Van Iseghem, S. (2004), "WASP-West Africa Swell Project - Final Report", 90+192. http://archimer.ifremer.fr/doc/00114/22537/
  9. Forristall, G.Z., Ewans, K., Olagnon, M. and Prevosto, M. (2013), "The West Africa Swell Project (Wasp)", Proceedings of the 32nd Int. Conf. on Offshore and Arctic Eng., OMAE 2013-11264.
  10. Gjevik, B., Krogstad, H.E., Lygre, A. and Rygg, O. (1987), "Long period swell wave events on Norwegian shelf", J. Phys. Oceanography, 18, 724-737
  11. Haver, S. (2013),"'Prediction of characteristic response for design purposes", Preliminary Revision 5, Statoil, Stavanger, Norway.
  12. Haver, S. (2016), "Stochastic description of ocean waves & response analysis and prediction of extremes", Lecture Note, Rev. 1, UIS/NTNU.
  13. Haver, S. and Nyhus, K.A. (1986), "A wave climate description for long term response calculations", OMAE, Tokyo.
  14. Kinsman, B. (1965), "Wind Waves", Englewood Cliffs, NJ: Prentice-Hall.
  15. Olagnon, M., Ewans, K., Forristall, G.Z. and Prevosto, M. (2013), "West Africa swell spectral shapes", Proceedings of the Int. Conf. on Offshore Mech. and Arctic Eng., OMAE 2013-11228.
  16. Prevosto, M., Ewans, K., Forristall, G.Z. and Olagnon, M. (2013), "Swell genesis, modelling and measurements in West Africa", Proceedings of the Int. Conf. on Offshore Mech. and Arctic Eng.,OMAE 2013-11201.
  17. Sabique, L. (2012), "Effect of Southern swell on the waves in the Northern Indian Ocean swell propagation, effect and seasonal variability", Lambert Academic Publishing (2012-06-12).
  18. Sabique, L., Annapurnaiah, K., Nair Balakrishnan, T.M. and Srinivas, K. (2011), "Contribution of Southern Indian Ocean swells on the wave heights in the Northern Indian Ocean", A modeling study, Ocean Eng., 43, 113-120.
  19. Samiksha, S.V., Vethamony, P., Aboobacker, V. and Rashmi, R. (2012), "'Propagation of Atlantic Ocean swells in the North Indian Ocean: A case study", Natural Hazards and Earth System Sciences, 12, 3605-3615. https://doi.org/10.5194/nhess-12-3605-2012
  20. Semedo, A., Suselj, K. and Rutgersson, A. (2009), "Variability of wind sea and swell waves in the North Atlantic based on ERA-40 re-analysis", Proceedings of the 8th European Wave and Tidal Energy Conference, Uppsala, Sweden.
  21. Snodgrass, F.E., Groves, G.W., Hasselmann, K.F., Miller, G.R., Munk, W.H. and Powers, W.M. (1966), "Propagation of swell across the pacific", Philos. T. R. Soc., London, 259, 431-497. https://doi.org/10.1098/rsta.1966.0022