Editorial Type:
Article
Article Type:
Research Article

Respective Roles of the Guinea Current and Local Winds on the Coastal Upwelling in the Northern Gulf of Guinea

S. Djakouré Laboratoire de Physique de l’Atmosphère et de Mécanique des Fluides, UFR SSMT, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire, and International Chair of Mathematical Physics and Applications (ICMPA-UNESCO Chair), University of Abomey-Calavi, Cotonou, Benin

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P. Penven Laboratoire d’Océanographie Physique et Spatiale, UMR 6523 CNRS/IFREMER/IRD/UBO, Plouzané, France

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B. Bourlès Laboratoire d’Études en Géophysique et Océanographie Spatiales, UMR 5566 CNES/CNRS/IRD/UPS, Plouzané, France, and International Chair of Mathematical Physics and Applications (ICMPA-UNESCO Chair), University of Abomey-Calavi, Cotonou, Benin

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V. Koné Centre de Recherches Océanologiques, Abidjan, Côte d’Ivoire

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J. Veitch South African Environmental Observation Network, Egagasini Node, Cape Town, South Africa

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Print Publication:
01 Jun 2017
DOI:
https://doi.org/10.1175/JPO-D-16-0126.1
Page(s):
1367–1387
Restricted access

Abstract

The northern Gulf of Guinea is a part of the eastern tropical Atlantic where oceanic conditions due to the presence of coastal upwelling may influence the regional climate and fisheries. The dynamics of this coastal upwelling is still poorly understood. A sensitivity experiment based on the Regional Oceanic Modeling System (ROMS) is carried out to assess the role of the detachment of the Guinea Current as a potential mechanism for coastal upwelling. This idealized experiment is performed by canceling the inertia terms responsible for the advection of momentum in the equations and comparing with a realistic experiment. The results exhibit two major differences. First, the Guinea Current is found to be highly sensitive to inertia, as it is no longer detached from the coast in the idealized experiment. The Guinea Current adjusts on an inertial boundary layer, the inertial terms defining its lateral extension. Second, the upwelling east of Cape Palmas disappears in absence of the Guinea Current detachment. This is in contrast with the upwelling east of Cape Three Points, which is still present. The results suggest that two different generation processes of the coastal upwelling need to be considered: the upwelling east of Cape Palmas (which is due to inertia, topographic variations, and advective terms effects resulting in important vertical pumping) and the upwelling east of Cape Three Points (which is principally induced by local winds). In addition to recent work ruling out the role of eddies, this study clarifies the processes responsible for this coastal upwelling.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Sandrine Djakouré, agre.djakoure@ird.fr

Abstract

The northern Gulf of Guinea is a part of the eastern tropical Atlantic where oceanic conditions due to the presence of coastal upwelling may influence the regional climate and fisheries. The dynamics of this coastal upwelling is still poorly understood. A sensitivity experiment based on the Regional Oceanic Modeling System (ROMS) is carried out to assess the role of the detachment of the Guinea Current as a potential mechanism for coastal upwelling. This idealized experiment is performed by canceling the inertia terms responsible for the advection of momentum in the equations and comparing with a realistic experiment. The results exhibit two major differences. First, the Guinea Current is found to be highly sensitive to inertia, as it is no longer detached from the coast in the idealized experiment. The Guinea Current adjusts on an inertial boundary layer, the inertial terms defining its lateral extension. Second, the upwelling east of Cape Palmas disappears in absence of the Guinea Current detachment. This is in contrast with the upwelling east of Cape Three Points, which is still present. The results suggest that two different generation processes of the coastal upwelling need to be considered: the upwelling east of Cape Palmas (which is due to inertia, topographic variations, and advective terms effects resulting in important vertical pumping) and the upwelling east of Cape Three Points (which is principally induced by local winds). In addition to recent work ruling out the role of eddies, this study clarifies the processes responsible for this coastal upwelling.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Sandrine Djakouré, agre.djakoure@ird.fr
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  • Adamec, D., and J. J. O’Brien, 1978: The seasonal upwelling in the Gulf of Guinea due to remote forcing. J. Phys. Oceanogr., 8, 1050–1060, doi:10.1175/1520-0485(1978)008<1050:TSUITG>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Allen, S. E., and B. M. Hickey, 2010: Dynamics of advection-driven upwelling over a shelf break submarine canyon. J. Geophys. Res., 115, C08018, doi:10.1029/2009JC005731.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Arfi, R., O. Pezennec, S. Cissoko, and M. Mensah, 1991: Variations spatiale et temporelle de la résurgence ivoiro-ghanéenne. Pêcheries Ouest-Africaines Variabilité, Instabilité et Changement, P. Cury and C. Roy, Eds., ORSTOM, 162–172.

  • Arnault, S., 1987: Tropical Atlantic geostrophic currents and ship drifts. J. Geophys. Res., 92, 5076–5088, doi:10.1029/JC092iC05p05076.

  • Athié, G., F. Marin, A.-M. Tréguier, B. Bourlès, and C. Guiavarc’h, 2009: Sensitivity of near-surface tropical instability waves to submonthly wind forcing in the tropical Atlantic. Ocean Modell., 30, 241–255, doi:10.1016/j.ocemod.2009.06.016.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Bakun, A., 1973: Coastal upwelling indices, west coast of North America 1946-71. NOAA Tech. Rep. NMFS SSRF-671, 112 pp.

  • Bakun, A., 1978: Guinea Current upwelling. Nature, 271, 147–150, doi:10.1038/271147a0.

  • Bakun, A., and C. S. Nelson, 1991: The seasonal cycle of wind-stress curl in subtropical eastern boundary current regions. J. Phys. Oceanogr., 21, 1815–1834, doi:10.1175/1520-0485(1991)021<1815:TSCOWS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Binet, D., 1997: Climate and pelagic fisheries in the Canary and Guinea Currents 1964-1993: The role of trade winds and the Southern Oscillation. Oceanol. Acta, 20, 177–190.

    • Search Google Scholar
    • Export Citation

  • Blayo, E., and L. Debreu, 1999: Adaptive mesh refinement for finite-difference ocean models: First experiments. J. Phys. Oceanogr., 29, 1239–1250, doi:10.1175/1520-0485(1999)029<1239:AMRFFD>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Bourlès, B., R. L. Molinari, E. Johns, W. Wilson, and K. Leaman, 1999: Upper layer currents in the western tropical North Atlantic. J. Geophys. Res., 104, 1361–1376, doi:10.1029/1998JC900025.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Boyer, D., and L. Tao, 1987: On the motion of linearly stratified rotating fluids past capes. J. Fluid Mech., 180, 429–449, doi:10.1017/S0022112087001885.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Caniaux, G., H. Giordani, J.-L. Redelsperger, F. Guichard, E. Key, and M. Wade, 2011: Coupling between the Atlantic cold tongue and West African monsoon in boreal spring and summer. J. Geophys. Res., 116, C04003, doi:10.1029/2010JC006570.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Chao, Y., A. Gangopadhyay, F. O. Bryan, and W. R. Holland, 1996: Modeling the Gulf Stream System: How far from reality? Geophys. Res. Lett., 23, 3155–3158, doi:10.1029/96GL03003.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Charney, J., 1955: The generation of ocean currents by wind. J. Mar. Res., 14, 477–498.

  • Clarke, A., 1979: On the generation of the seasonal coastal upwelling in the Gulf of Guinea. J. Geophys. Res., 84, 3743–3751, doi:10.1029/JC084iC07p03743.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Colin, C., 1988: Coastal upwelling events in front of the Ivory Coast during the FOCAL program. Oceanol. Acta, 11, 125–138.

  • Colin, C., 1991: Sur les upwellings équatorial et côtier (5°N) dans le Golfe de Guinée. Oceanol. Acta, 14, 223–240.

  • Colin, C., Y. Gallardo, R. Chuchla, and S. Cissoko, 1993: Environnements climatique et océanographique sur le plateau continental de Côte d’Ivoire. Environnement et Ressources aquatiques de Côte d’Ivoire: 1. Le Milieu Marin, P. Le Loeuff, E. Marchal, and J. Amon Kothias, Eds., ORSTOM, 75–110.

  • Crépon, M., C. Richez, and M. Chartier, 1984: Effects of coastline geometry on upwellings. J. Phys. Oceanogr., 14, 1365–1382, doi:10.1175/1520-0485(1984)014<1365:EOCGOU>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Cury, P., and C. Roy, 2002: Environmental forcing and fisheries resources in Côte d’Ivoire and Ghana: Did something happen? Environmental Forcing and Sustainable Development of Marine Resources, J. M. McGlade et al., Eds., Vol. 11, The Gulf of Guinea Large Marine Ecosystem, Elsevier, 241–260.

    • Crossref
    • Export Citation

  • Da Silva, A., C. Young, and S. Levitus, 1994: Algorithms and Procedures. Vol. 1, Atlas of Surface Marine Data 1994, NOAA Atlas NESDIS 6, 83 pp.

  • Debreu, L., and E. Blayo, 2008: Two-way embedding algorithms: A review. Ocean Dyn., 58, 415–428, doi:10.1007/s10236-008-0150-9.

  • Debreu, L., P. Marchesiello, P. Penven, and G. Cambon, 2012: Two-way nesting in split-explicit ocean models: Algorithms, implementation and validation. Ocean Modell., 49–50, 1–21, doi:10.1016/j.ocemod.2012.03.003.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Djakouré, S., P. Penven, B. Bourlès, J. Veitch, and V. Koné, 2014: Coastally trapped eddies in the north of the Gulf of Guinea. J. Geophys. Res. Oceans, 119, 6805–6819, doi:10.1002/2014JC010243.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Ducet, N., P. Y. L. Traon, and G. Reverdin, 2000: Global high-resolution mapping of ocean circulation from TOPEX/Poseidon and ERS-1 and -2. J. Geophys. Res., 105, 19 477–19 498, doi:10.1029/2000JC900063.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Dufois, F., P. Penven, C. P. Whittle, and J. Veitch, 2012: On the warm nearshore bias in Pathfinder monthly SST products over eastern boundary upwelling systems. Ocean Modell., 47, 113–118, doi:10.1016/j.ocemod.2012.01.007.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Dunn, J. R., and K. R. Ridgway, 2002: Mapping ocean properties in regions of complex topography. Deep-Sea Res. I, 49, 591–604, doi:10.1016/S0967-0637(01)00069-3.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Durski, S. M., R. Samelson, J. Allen, and G. D. Egbert, 2008: Normal-mode instabilities of a time-dependent coastal upwelling jet. J. Phys. Oceanogr., 38, 2056–2071, doi:10.1175/2008JPO3803.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Enriquez, A. G., and C. A. Friehe, 1995: Effects of wind stress and wind stress curl variability on coastal upwelling. J. Phys. Oceanogr., 25, 1651–1671, doi:10.1175/1520-0485(1995)025<1651:EOWSAW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Fofonoff, N. P., 1954: Steady flow in a frictionless homogeneous ocean. J. Mar. Res., 13, 254–262.

  • Garzoli, S. L., and E. J. Katz, 1983: The forced annual reversal of the Atlantic North Equatorial Countercurrent. J. Phys. Oceanogr., 13, 2082–2090, doi:10.1175/1520-0485(1983)013<2082:TFAROT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Gourdeau, L., J. Verron, T. Delcroix, A. J. Busalacchi, and R. Murtugudde, 2000: Assimilation of TOPEX/Poseidon altimetric data in a primitive equation model of the tropical Pacific Ocean during the 1992–1996 El Niño-Southern Oscillation period. J. Geophys. Res., 105, 8473–8488, doi:10.1029/2000JC900011.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Gruber, N., Z. Lachkar, H. Frenzel, P. Marchesiello, M. Munnich, J. C. McWilliams, T. Nagai, and G.-K. Plattner, 2011: Eddy-induced reduction of biological production in eastern boundary upwelling systems. Nat. Geosci., 4, 787–792, doi:10.1038/ngeo1273.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Gu, G., and R. Adler, 2004: Seasonal evolution and variability associated with the African monsoon system. J. Climate, 17, 3364–3377, doi:10.1175/1520-0442(2004)017<3364:SEAVAW>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Hardman-Mountford, N. J., and J. M. McGlade, 2003: Seasonal and interannual variability of oceanographic processes in the Gulf of Guinea: An investigation using AVHRR sea surface temperature data. Int. J. Remote Sens., 24, 3247–3268, doi:10.1080/0143116021000021297.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Houghton, R. W., 1983: Seasonal variations of the subsurface thermal structure in the Gulf of Guinea. J. Phys. Oceanogr., 13, 2070–2081, doi:10.1175/1520-0485(1983)013<2070:SVOTST>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Hsueh, Y., and J. J. O’Brien, 1971: Steady coastal upwelling induced by an alongshore current. J. Phys. Oceanogr., 1, 180–186, doi:10.1175/1520-0485(1971)001<0180:SCUIBA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Hughes, R. L., 1981: The influence of thermocline slope on equatorial thermocline displacement. Dyn. Atmos. Oceans, 5, 147–157, doi:10.1016/0377-0265(81)90008-7.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Ingham, M., 1970: Coastal upwelling in the northwestern Gulf of Guinea. Bull. Mar. Sci., 20, 1–34.

  • Janowitz, G. S., and L. J. Pietrafesa, 1982: The effects of alongshore variation in bottom topography on a boundary current (topographically induced upwelling). Cont. Shelf Res., 1, 123–141, doi:10.1016/0278-4343(82)90001-2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • José, Y., 2013: Mesoscale structuring of the pelagic ecosystem in the Mozambique Channel: A modelling approach. Ph.D. thesis, University of Cape Town, 194 pp. [Available from University of Cape Town, Rondebosch, Cape Town, 7700, South Africa.]

  • José, Y., P. Penven, O. Aumont, E. Machu, C. Moloney, F. Shillington, and O. Maury, 2016: Suppressing and enhancing effects of mesoscale dynamics on biological production in the Mozambique Channel. J. Mar. Syst., 158, 129–139, doi:10.1016/j.jmarsys.2016.02.003.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Jouanno, J., F. Marin, Y. D. Penhoat, J.-M. Molines, and J. Sheinbaum, 2011: Seasonal modes of surface cooling in the Gulf of Guinea. J. Phys. Oceanogr., 41, 1408–1416, doi:10.1175/JPO-D-11-031.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Katz, E., and S. Garzoli, 1982: Response of the western equatorial Atlantic Ocean to an annual wind cycle. J. Mar. Res., 40, 307–327.

  • Kolodziejczyk, N., 2008: Analyse de la circulation de subsurface et de sa variabilité dans le Golfe de Guinée. Ph.D. thesis, Thèse de doctorat de l’Université de Bretagne, 256 pp. [Available from Université de Bretagne, 3 Rue des Archives, 29238 Brest, France.]

  • Koranteng, K., and J. M. McGlade, 2001: Climatic trends in continental shelf waters off Ghana and in the Gulf of Guinea, 1963–1992. Oceanol. Acta, 24, 187–198, doi:10.1016/S0399-1784(01)01140-9.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Large, W. G., J. C. McWilliams, and S. C. Doney, 1994: Oceanic vertical mixing: A review and a model with a nonlocal boundary layer parameterization. Rev. Geophys., 32, 363–403, doi:10.1029/94RG01872.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Lemasson, L., and J. Rébert, 1973: Circulation dans le Golfe de Guinée: Etude de la région d’origine du sous-courant ivoirien. Cah. ORSTOM, Ser. Oceanogr., 11, 303–316.

    • Search Google Scholar
    • Export Citation

  • Longhurst, A. R., 1962: A review of the oceanography of the Gulf of Guinea. Bull. Inst. Fr. Afr. Noire, 24, 633–663.

  • Lumpkin, R., and G. Johnson, 2013: Global ocean surface velocities from drifters: Mean, variance, El Niño–Southern Oscillation response, and seasonal cycle. J. Geophys. Res. Oceans, 118, 2992–3006, doi:10.1002/jgrc.20210.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Lutjeharms, J. R. E., and E. Machu, 2000: An upwelling cell inshore of the East Madagascar Current. Deep-Sea Res. I, 47, 2405–2411, doi:10.1016/S0967-0637(00)00026-1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Machu, E., J. R. E. Lutjeharms, A. M. Webb, and H. M. V. Aken, 2002: First hydrographic evidence of the southeast Madagascar upwelling cell. Geophys. Res. Lett., 29, 2009, doi:10.1029/2002GL015381.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Marchal, E., and J. Picaut, 1977: Répartition et abondance évaluées par écho-integration des poissons du plateau ivoiro-ghanéen en relation avec les upwellings locaux. J. Rech. Oceanogr., 2, 39–58.

    • Search Google Scholar
    • Export Citation

  • Marchesiello, P., and P. Estrade, 2009: Eddy activity and mixing in upwelling systems: A comparative study of northwest Africa and California regions. Int. J. Earth Sci., 98, 299–308, doi:10.1007/s00531-007-0235-6.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Marchesiello, P., and P. Estrade, 2010: Upwelling limitation by onshore geostrophic flow. J. Mar. Res., 68, 37–62, doi:10.1357/002224010793079004.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Marchesiello, P., J. C. McWilliams, and A. Shchepetkin, 2001: Open boundary conditions for long-term integration of regional oceanic models. Ocean Modell., 3, 1–20, doi:10.1016/S1463-5003(00)00013-5.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Marchesiello, P., J. C. McWilliams, and A. Shchepetkin, 2003: Equilibrium structure and dynamics of the California Current System. J. Phys. Oceanogr., 33, 753–783, doi:10.1175/1520-0485(2003)33<753:ESADOT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Marchesiello, P., L. Debreu, and X. Couvelard, 2009: Spurious diapycnal mixing in terrain-following coordinate models: The problem and a solution. Ocean Modell., 26, 156–169, doi:10.1016/j.ocemod.2008.09.004.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Menkès, C., and Coauthors, 2002: A whirling ecosystem in the equatorial Atlantic. Geophys. Res. Lett., 29, 1553, doi:10.1029/2001GL014576.

  • Moore, W., P. Hisard, J. McCreary, J. Merle, J. O’Brien, J. Picaut, J. Verstraete, and C. Wunsch, 1978: Equatorial adjustment in the eastern Atlantic Ocean. Geophys. Res. Lett., 5, 637–640, doi:10.1029/GL005i008p00637.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Oke, P. R., and J. H. Middleton, 2000: Topographically induced upwelling off eastern Australia. J. Phys. Oceanogr., 30, 512–531, doi:10.1175/1520-0485(2000)030<0512:TIUOEA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Opoku-Ankomah, Y., and I. Cordery, 1994: Atlantic sea surface temperatures and rainfall variability in Ghana. J. Climate, 7, 551–558, doi:10.1175/1520-0442(1994)007<0551:ASSTAR>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Özgökmen, T. M., E. P. Chassignet, and A. M. Paiva, 1997: Impact of wind forcing, bottom topography, and inertia on midlatitude jet separation in a quasigeostrophic model. J. Phys. Oceanogr., 27, 2460–2476, doi:10.1175/1520-0485(1997)027<2460:IOWFBT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Penven, P., C. Roy, A. Colin de Verdiere, and J. Largier, 2000: Simulation of a coastal jet retention process using a barotropic model. Oceanol. Acta, 23, 615–634, doi:10.1016/S0399-1784(00)01106-3.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Penven, P., V. Echevin, J. Pasapera, F. Colas, and J. Tam, 2005: Average circulation, seasonal cycle, and mesoscale dynamics of the Peru Current system: A modeling approach. J. Geophys. Res., 110, C10021, doi:10.1029/2005JC002945.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Philander, S. G. H., 1979: Upwelling in the Gulf of Guinea. J. Mar. Res., 37, 23–33.

  • Philander, S. G. H., and R. C. Pacanowski, 1986: A model of the seasonal cycle in the tropical Atlantic Ocean. J. Geophys. Res., 91, 14 192–14 206, doi:10.1029/JC091iC12p14192.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Picaut, J., 1983: Propagation of the seasonal upwelling in the eastern equatorial Atlantic. J. Phys. Oceanogr., 13, 18–37, doi:10.1175/1520-0485(1983)013<0018:POTSUI>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Pringle, J. M., 2002: Enhancement of wind-driven upwelling and downwelling by alongshore bathymetric variability. J. Phys. Oceanogr., 32, 3101–3112, doi:10.1175/1520-0485(2002)032<3101:EOWDUA>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Richardson, P. L., and D. Walsh, 1986: Mapping climatological seasonal variations of surface currents in the tropical Atlantic using ship drifts. J. Geophys. Res., 91, 10 537–10 550, doi:10.1029/JC091iC09p10537.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Richardson, P. L., and G. Reverdin, 1987: Seasonal cycle of velocity in the Atlantic North Equatorial Countercurrent as measured by surface drifters, current meters, and ship drifts. J. Geophys. Res., 92, 3691–3708, doi:10.1029/JC092iC04p03691.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Rio, M.-H., S. Guinehut, and G. Larnicol, 2011: New CNES-CLS09 global mean dynamic topography computed from the combination of GRACE data, altimetry, and in situ measurements. J. Geophys. Res., 116, C07018, doi:10.1029/2010JC006505.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Risien, C. M., and D. B. Chelton, 2008: A global climatology of surface wind and wind stress fields from eight years of QuikSCAT scatterometer data. J. Phys. Oceanogr., 38, 2379–2413, doi:10.1175/2008JPO3881.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Roy, C., 1995: The Côte d’Ivoire and Ghana coastal upwellings: Dynamics and changes. Dynamics and Use of Sardinella Resources from Upwelling off Ghana and Ivory Coast, X. Bard and K. A. Koranteng, Eds., ORSTOM, 346–361.

  • Schott, F. A., J. P. McCreary Jr., and G. C. Johnson, 2004: Shallow overturning circulations of the tropical-subtropical oceans. Earth’s Climate, Geophys. Monogr., Vol. 147, Amer. Geophys. Union, 261–304.

    • Crossref
    • Export Citation

  • Schumann, E. H., L.-A. Perrins, and I. T. Hunter, 1982: Upwelling along the south coast of the Cape Province, South Africa. S. Afr. J. Sci., 78, 238–242.

    • Search Google Scholar
    • Export Citation

  • Servain, J., J. Picaut, and J. Merle, 1982: Evidence of remote forcing in the equatorial Atlantic Ocean. J. Phys. Oceanogr., 12, 457–463, doi:10.1175/1520-0485(1982)012<0457:EORFIT>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Shchepetkin, A. F., and J. C. McWilliams, 2003: A method for computing horizontal pressure force in an oceanic model with a non-aligned vertical coordinate. J. Geophys. Res., 108, 3090, doi:10.1029/2001JC001047.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Shchepetkin, A. F., and J. C. McWilliams, 2005: The Regional Oceanic Modeling System (ROMS): A split-explicit, free-surface, topography-following-coordinate oceanic model. Ocean Modell., 9, 347–404, doi:10.1016/j.ocemod.2004.08.002.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Song, Y., and D. B. Haidvogel, 1994: A semi-implicit ocean circulation model using a generalized topography-following coordinate system. J. Comput. Phys., 115, 228–244, doi:10.1006/jcph.1994.1189.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Stramma, L., J. Fischer, P. Brandt, F. Schott, G. Goni, and P. Malanotte-Rizzoli, 2003: Circulation, variability and near-equatorial meridional flow in the central tropical Atlantic. Interhemispheric Water Exchange in the Atlantic Ocean, G. J. Goni and P. Rizzoli, Eds., Elsevier Oceanography Series, Vol. 68, Elsevier, 1–22.

    • Crossref
    • Export Citation

  • Toualy, E., G. Stanojevic, K. Kouadio, and A. Aman, 2012: Multi-decadal variability of sea surface temperature in the northern coast of the Gulf of Guinea. Asian J. Appl. Sci., 5, 552–562, doi:10.3923/ajaps.2012.552.562.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Varlet, F., 1958: Les traits essentiels du régime côtier de l’Atlantique près d’Abidjan (Côte d’Ivoire). Bull. l’IFAN Sci. Nat., 20A, 1089–1102.

    • Search Google Scholar
    • Export Citation

  • Veitch, J., P. Penven, and F. Shillington, 2009: The Benguela: A laboratory for comparative modeling studies. Prog. Oceanogr., 83, 296–302, doi:10.1016/j.pocean.2009.07.008.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Veitch, J., P. Penven, and F. Shillington, 2010: Modeling equilibrium dynamics of the Benguela Current system. J. Phys. Oceanogr., 40, 1942–1964, doi:10.1175/2010JPO4382.1.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Wacongne, S., 1989: Dynamical regimes of a fully nonlinear stratified model of the Atlantic Equatorial Undercurrent. J. Geophys. Res., 94, 4801–4815, doi:10.1029/JC094iC04p04801.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Wiafe, G., H. B. Yaqub, M. A. Mensah, and C. L. J. Frid, 2008: Impact of climate change on long-term zooplankton biomass in the upwelling region of the Gulf of Guinea. ICES J. Mar. Sci., 65, 318–324, doi:10.1093/icesjms/fsn042.

    • Crossref
    • Search Google Scholar
    • Export Citation

  • Wooster, W. S., and J. J. L. Reid, 1963: Eastern boundary currents. Physical Oceanography, M. N. Hill, Eds., The Sea—Ideas and Observations on Progress in the Study of the Seas, Vol. 1, John Wiley and Sons, 253–280.

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