Main processes of the Atlantic cold tongue interannual variability

  • Yann Planton
  • Aurore Voldoire
  • Hervé Giordani
  • Guy Caniaux
Article

Abstract

The interannual variability of the Atlantic cold tongue (ACT) is studied by means of a mixed-layer heat budget analysis. A method to classify extreme cold and warm ACT events is proposed and applied to ten various analysis and reanalysis products. This classification allows 5 cold and 5 warm ACT events to be selected over the period 1982–2007. Cold (warm) ACT events are defined by the presence of negative (positive) sea surface temperature (SST) anomalies at the center of the equatorial Atlantic in late boreal spring, preceded by negative (positive) zonal wind stress anomalies in the western equatorial Atlantic. An ocean general circulation model capable of reconstructing the interannual variability of the ACT correctly is used to demonstrate that cold ACT events develop rapidly from May to June mainly due to intense cooling by vertical mixing and horizontal advection. The simulated cooling at the center of the basin is the result of the combined effects of non-local and local processes. The non-local process is an upwelling associated with an eastward-propagating Kelvin wave, which makes the mixed-layer more shallow and preconditions the upper layers to be cooled by an intense heat loss at the base of the mixed-layer, which is amplified by a stronger local injection of energy from the atmosphere. The early cooling by vertical mixing in March is also shown to be a good predictor of June cooling. In July, horizontal advection starts to warm the mixed-layer abnormally and damps SST anomalies. The advection anomalies, which result from changes in the horizontal temperature gradient, are associated in some cases with the propagation of Rossby waves along the equator. During warm ACT events, processes are reversed, generating positive SST anomalies: a downwelling Kelvin wave triggers stratification anomalies and mixed-layer depth anomalies, amplified by a weaker injection of energy from the atmosphere in May–June. In July, warm ACT events are abnormally cooled due to negative horizontal advection anomalies resulting from processes similar to those that occur during cold ACT events. This additional cooling process extends the period of cooling of the ACT, reducing SST anomalies.

Keywords

Atlantic cold tongue Equatorial Atlantic Interannual variability Mixed-layer heat budget Oceanic mixed-layer processes Vertical mixing 

Notes

Acknowledgements

The authors gratefully acknowledge comments of the anonymous reviewers that led to significant improvements. The research leading to these results has received funding by the European Union’s Seventh Framework Programme FP7 PREFACE under grant agreement 603521.

References

  1. Adamec D, O’Brien JJ (1978) The seasonal upwelling in the Gulf of Guinea due to remote forcing. J Phys Oceanogr 8(6):1050–1060. doi:10.1175/1520-0485(1978)008<1050:TSUITG>2.0.CO;2 CrossRefGoogle Scholar
  2. Balmaseda MA, Mogensen K, Molteni F, Weaver AT (2010) The NEMOVAR-COMBINE ocean re-analysis. COMBINE Technical report No. 1Google Scholar
  3. Balmaseda MA, Mogensen K, Weaver AT (2013) Evaluation of the ECMWF ocean reanalysis system ORAS4. Q J R Meteorol Soc 139:1132–1161. doi:10.1002/qj.2063 CrossRefGoogle Scholar
  4. Battisti DS, Hirst AC (1989) Interannual variability in a tropical atmosphere-ocean model: influence of the basic state, ocean geometry and nonlinearity. J Atmos Sci 46(12):1687–1712. doi:10.1175/1520-0469(1989)046<1687:IVIATA>2.0.CO;2 CrossRefGoogle Scholar
  5. Blanke B, Delecluse P (1993) Variability of the tropical Atlantic ocean simulated by a general circulation model with two different mixed-layer physics. J Phys Oceanogr 23:1363–1388. doi:10.1175/1520-0485(1993)023<1363:VOTTAO>2.0.CO;2 CrossRefGoogle Scholar
  6. Brandt P, Funk A, Tantet A, Johns WE, Fischer J (2014) The equatorial undercurrent in the central Atlantic and its relation to tropical Atlantic variability. Clim Dyn 43(11):2985–2997. doi:10.1007/s00382-014-2061-4 CrossRefGoogle Scholar
  7. Burls NJ, Reason CJC, Penven P, Philander SG (2012) Energetics of the tropical Atlantic zonal mode. J Clim 25(21):7442–7466. doi:10.1175/JCLI-D-11-00602.1 CrossRefGoogle Scholar
  8. Cabanes C, Grouazel A, Von Schuckmann K, Hamon M, Turpin V, Coatanoan C, Paris F, Guinehut S, Boone C, Ferry N, de Boyer Montégut C, Carval T, Reverdin G, Pouliquen S, Le Traon PY (2013) The CORA dataset: validation and diagnostics of in-situ ocean temperature and salinity measurements. Ocean Sci 9(special issue):1–18. doi:10.5194/os-9-1-2013
  9. Caniaux G, Giordani H, Redelsperger JL, Guichard F, Key E, Wade M (2011) Coupling between the Atlantic cold tongue and the West African Monsoon in boreal spring and summer. J Geophys Res 116:C04003. doi:10.1029/2010JC006570 CrossRefGoogle Scholar
  10. Carr ME, Fredrichs MAM, Schmeltz M, Aita MN, Antoine D, Arrigo KR, Asanuma I, Aumont O, Barber R, Behrefeld M, Bidigare R, Buitenhuis E, Campbel J, Ciotti A, Dierssen H, Dowell M, Dunne J, Esaias W, Gentili B, Groom S, Hoepf N (2006) A comparison of global estimates of marine primary production from ocean color. Deep Sea Res II 53(5–7):741–770. doi:10.1016/j.dsr2.2006.01.028 CrossRefGoogle Scholar
  11. Clarke AJ, Wang JG, Van Gorder S (2000) A simple warm-pool displacement ENSO model. J Phys Oceanogr 30(7):1679–1691. doi:10.1175/1520-0485(2000)030<1679:ASWPDE>2.0.CO;2 CrossRefGoogle Scholar
  12. Colin C (1989) Sur la variabilité dans le Golfe de Guinée. Nouvelles considérations sur les mécanismes d’upwelling. Ph.D. thesis, Muséum National d’Histoire Naturelle de ParisGoogle Scholar
  13. Dai A, Trendberth KE (2002) Estimates of freshwater discharge from continents: latitudinal and seasonal variations. J Hydrometeorol 3(6):660–687. doi:10.1175/1525-7541(2002)003<0660:EOFDFC>2.0.CO;2 CrossRefGoogle Scholar
  14. Danabasoglu G, Yeager SG, Bailey D, Behrens E, Bentsen M, Bi D, Biastoch A, Boning C, Bozec A, Canuto V, Cassou C, Chassignet E, Coward AC, Danilov S, Diansky N, Drange H, Farneti R, Fernandez E, Fogli PG, Forget G, Fujii Y, Griffies SM, Gusev A, Heimbach P, Howard A, Jung T, Kelley M, Large WG, Leboissetier A, Lu J, Madec G, Marsland SJ, Masina S, Navarra A, Nurser AJG, Pirani A, Salas y Melia D, Samuels BL, Scheinert M, Sidorenko D, Treguier AM, Tsujino H, Uotila P, Valcke S, Voldoire A, Wang Q (2014) North Atlantic simulations in the coordinated ocean-sea ice reference experiments phase II (CORE-II). Part I: mean states. Ocean Model 73:76–107. doi:10.1016/j.ocemod.2013.10.005 CrossRefGoogle Scholar
  15. de Boyer Montégut C, Madec G, Fischer AS, Lazar A, ludicone D (2004) Mixed layer depth over the global ocean : An examination of profile sata and a profile-based climatology. J Geophys Res 109:C12003. doi:10.1029/2004JC002378 CrossRefGoogle Scholar
  16. Dee DP, Uppala SM, Simmons AJ, Berrisford P, Poli P, Kobayashi S, Andrae U, Balmaseda MA, Balsamo G, Bauer P, Bechtold P, Beljaars ACM, van de Berg L, Bidlot J, Bormann N, Delsol C, Dragani R, Fuentes M, Geer AJ, Haimberger L, Healy SB, Hersbach H, Hólm EV, Isaksen L, Kållberg P, Köhler M, Matricardi M, McNally AP, Monge-Sanz BM, Morcrette J-J, Park B-K, Peubey C, de Rosnay P, Tavolato C, Thépaut J-N, Vitart F (2011) The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q J R Meteorol Soc 137:553–597. doi:10.1002/qj.828 CrossRefGoogle Scholar
  17. Delcroix T, Picaut J, Eldin G (1991) Equatorial Kelvin and Rossby waves evidenced in the Pacific Ocean through Geosat sea level and surface current anomalies. J Geophys Res: Oceans 96(S01):3249–3262. doi:10.1029/90JC01758 CrossRefGoogle Scholar
  18. Ding H, Keenlyside NS, Latif M (2010) Equatorial Atlantic interannual variability: role of heat content. J Geophys Res 115:C09020. doi:10.1029/2010JC006304 Google Scholar
  19. Foltz GR, McPhaden MJ (2006) The role of oceanic heat advection in the evolution of tropical North and South Atlantic SST anomalies. J Clim 19(23):6122–6138. doi:10.1175/JCLI3961.1 CrossRefGoogle Scholar
  20. Foltz GR, Grodsky SA, Carton JA, McPhaden MJ (2003) Seasonal mixed layer heat budget of the tropical Atlantic Ocean. J Geophys Res 108(C5):3146. doi:10.1029/2002jc001584 CrossRefGoogle Scholar
  21. Giordani H, Caniaux G (2011) Diagnosing vertical motion in the Equatorial Atlantic. Ocean Dyn 61(12):1995–2018. doi:10.1007/s10236-011-0467-7 CrossRefGoogle Scholar
  22. Giordani H, Caniaux G, Voldoire A (2013) Intraseasonal mixed-layer heat budget in the equatorial Atlantic during the cold tongue development in 2006. J Geophys Res: Oceans 118:650–671. doi:10.1029/2012JC008280 CrossRefGoogle Scholar
  23. Góes M, Wainer I (2003) Equatorial currents transport changes for extreme warm and cold events in the Atlantic Ocean. Geophys Res Lett 30(5):8006. doi:10.1029/2002GL015707 CrossRefGoogle Scholar
  24. Good SA, Martin MJ, Rayner NA (2013) EN4: quality controlled ocean temperature and salinity profiles and monthly objective analyses with uncertainty estimates. J Geophys Res: Oceans 118:6704–6716. doi:10.1002/2013JC009067 CrossRefGoogle Scholar
  25. Gregg MC, Peters H, Wesson JC, Oakey NS, Shay TJ (1985) Intensive measurements of turbulence and shear in the equatorial undercurrent. Nature 318:140–144. doi:10.1038/318140a0 CrossRefGoogle Scholar
  26. Griffies SM, Winton M, Samuels B, Danabasoglu G, Yeager SG, Marsland S, Drange H, Brentsen M (2012) Datasets and protocol for the CLIVAR WGOMD Coordinated Ocean-sea ice Reference Experiments (COREs). WCRP Report No. 21/2012, pp 21Google Scholar
  27. Gu G, Adler RF (2004) Seasonal evolution and variability associated with the West African Monsoon system. J Clim 17:3364–3377. doi:10.1175/1520-0442(2004)017<3364:SEAVAW>2.0.CO;2 CrossRefGoogle Scholar
  28. Guinehut S, Dhomps AL, Larnicol G, Le Traon PY (2012) High resolution 3D temperature and salinity fields derived from in situ and satellite observations. Ocean Sci 8(5):845–857. doi:10.5194/os-8-845-2012 CrossRefGoogle Scholar
  29. Hastenrath S, Lamb P (1978) On the dynamics and climatology of surface flow over the equatorial oceans. Tellus 30:436–448. doi:10.1111/j.2153-3490.1978.tb00859.x CrossRefGoogle Scholar
  30. Hieronymus M, Nycander J (2013) The budgets of heat and salinity in NEMO. Ocean Model 67:28–38. doi:10.1016/j.ocemod.2013.03.006 CrossRefGoogle Scholar
  31. Hormann V, Brandt P (2007) Atlantic Equatorial Undercurrent and associated cold tongue variability. J Geophys Res: Oceans 112:C06017. doi:10.1029/2006jc003931 CrossRefGoogle Scholar
  32. Houghton RW (1989) Influence of local and remote wind forcing in the Gulf of Guinea. J Geophys Res: Oceans 94(C4):4816–4828. doi:10.1029/JC094iC04p04816 CrossRefGoogle Scholar
  33. Hummels R, Dengler M, Bourlès B (2013) Seasonal and regional variability of upper ocean diapycnal heat flux in the Atlantic Cold Tongue. Prog Oceanogr 111:52–74. doi:10.1016/j.pocean.2012.11.001 CrossRefGoogle Scholar
  34. Hummels R, Dengler M, Brandt P, Schlundt M (2014) Diapycnal heat flux and mixed layer heat budget within in the Atlantic Cold Tongue. Clim Dyn 43(11):3179–3199. doi:10.1007/s00382-014-2339-6 CrossRefGoogle Scholar
  35. Jackett DR, McDougall TJ (1995) Minimal adjustment of hydrographic profiles to achieve static stability. J Atmos Oceanic Technol 12(2):381–389. doi:10.1175/1520-0426(1995)012<0381:MAOHPT>2.0.CO;2 CrossRefGoogle Scholar
  36. Jochum M, Murtugudde R (2006) Temperature advection by tropical instability waves. J Phys Oceanogr 36(4):592–605. doi:10.1175/JPO2870.1 CrossRefGoogle Scholar
  37. Jochum M, Murtugudde R, Ferrari R, Malanotte-Rizzoli P (2005) The impact of horizontal resolution on the tropical heat budget in an Atlantic Ocean Model. J Clim 18(6):841–851. doi:10.1175/JCLI-3288.1 CrossRefGoogle Scholar
  38. Jouanno J, Marin F, duPenhoat Y, Molines JM, Sheinbaum J (2011a) Seasonal modes of surface cooling in the Gulf of Guinea. J Phys Oceanogr 41(7):1408–1416. doi:10.1175/JPO-D-11-031.1 CrossRefGoogle Scholar
  39. Jouanno J, Marin F, duPenhoat Y, Sheinbaum J, Molines JM (2011b) Seasonal heat balance in the upper 100 m of the Equatorial Atlantic Ocean. J Geophys Res 116:C09003. doi:10.1029/2010JC006912 CrossRefGoogle Scholar
  40. Jouanno J, Marin F, duPenhoat Y, Molines JM (2013) Intraseasonal modulation of the surface cooling in the Gulf of Guinea. J Phys Oceanogr 43(2):382–401. doi:10.1175/JPO-D-12-053.1 CrossRefGoogle Scholar
  41. Kanamitsu M, Ebisuzaki W, Woolen J, Yang SK, Hnilo JJ, Fiorino M, Potter GL (2002) NCEP-DOE AMIP-II Reanalysis (R-2). Bull Am Meteorol Soc 83(11):1631–1643. doi:10.1175/BAMS-83-11-1631 CrossRefGoogle Scholar
  42. Keenlyside NS, Latif M (2007) Understanding equatorial Atlantic interannual variability. J Clim 20:131–142. doi:10.1175/JCLI3992.1 CrossRefGoogle Scholar
  43. Large WG, Yeager SG (2009) The global climatology of an interannually varying air-sea flux data set. Clim Dyn 33:341–364. doi:10.1007/s00382-008-041-3 CrossRefGoogle Scholar
  44. Lengaigne M, Menkes C, Aumont O, Gorgues T, Bopp L, André JM, Madec G (2007) Influence of the oceanic biology on the tropical Pacific climate in a coupled general circulation model. Clim Dyn 28(5):503–516. doi:10.1007/s00382-006-0200-2 CrossRefGoogle Scholar
  45. Lien RC, Caldwell DR, Moum JN (1995) Turbulence variability at the equator in the central Pacific at the beginning of the 1991–1993 El Niño. J Geophys Res: Oceans 100(C4):6881–6898. doi:10.1029/94JC03312 CrossRefGoogle Scholar
  46. Lien RC, D’Asaro EA, Menkes CE (2008) Modulation of equatorial turbulence by tropical instability waves. Geophys Res Lett 35(24):L24607. doi:10.1029/2008GL035860 CrossRefGoogle Scholar
  47. Lübbecke JF, McPhaden MJ (2012) On the Inconsistent Relationship between Pacific and Atlantic Niños. J Clim 25(12):4294–4303. doi:10.1175/JCLI-D-11-00553.1 CrossRefGoogle Scholar
  48. Lübbecke JF, McPhaden MJ (2013) A comparative stability analysis of Atlantic and Pacific Niño modes. J Clim 26(16):5965–5980. doi:10.1175/JCLI-D-12-00758.1 CrossRefGoogle Scholar
  49. Lübbecke JF, Burls NJ, Reason CJ, McPhaden MJ (2014) Variability in the South Atlantic anticyclone and the Atlantic Niño mode. J Clim 27:8135–8150. doi:10.1175/JCLI-D-14-00202.1 CrossRefGoogle Scholar
  50. Madec G (2008) NEMO ocean engine. Note du Pole de modélisation, Institut Pierre-Simon Laplace (IPSL), France, No 27 ISSN No 1288–1619Google Scholar
  51. Marin F, Caniaux G, Giordani H, Bourlès B, Gouriou Y, Key E (2009) Why were sea surface temperatures so different in the Eastern Equatorial Atlantic in June 2005 and 2006? J Phys Oceanogr 39(6):1416–1431. doi:10.1175/2008JPO4030.1 CrossRefGoogle Scholar
  52. Mazeika PA (1968) Mean monthly sea surface temperatures and zonal anomalies of the tropical Atlantic. folio 16. Am. Geographical Soc., New YorkGoogle Scholar
  53. Merle J, Fieux M, Hisard P (1979) Annual signal and interannual anomalies of sea surface temperature in the eastern equatorial Atlantic Ocean. Deep-Sea Res GATE Suppl II to V, 26:77–102Google Scholar
  54. Morel A (1988) Optical modeling of the upper ocean in relation to its biogenous matter content (case-I waters). J Geophys Res: Oceans 93(C9):10749–10768. doi:10.1029/JC09iC09p10749 CrossRefGoogle Scholar
  55. Morel A, Maritorena S (2001) Bio-optical properties of oceanic waters: a reappraisal. J Geophys Res: Oceans 106(C4):7163–7180. doi:10.1029/2000JC000319 CrossRefGoogle Scholar
  56. Moum JN, Caldwell DR (1985) Local influences on shear-flow turbulence in the Equatorial Ocean. Science 230(4723):315–316. doi:10.1126/science.230.4723.315 CrossRefGoogle Scholar
  57. Nguyen H, Thorncroft CD, Zhang C (2011) Guinean coastal rainfall of the West African Monsoon. Q J R Meteorol Soc 137:1828–1840. doi:10.1002/qj.867 CrossRefGoogle Scholar
  58. Okumura Y, Xie SP (2004) Interaction of the Atlantic equatorial cold tongue and the African Monsoon. J Clim 17:3589–3602. doi:10.1175/1520-0442(2004)017<3589:IOTAEC>2.0.CO;2 CrossRefGoogle Scholar
  59. Perez RC, Lumpkin R, Johns WE, Foltz GR, Hormann V (2012) Interannual variations of Atlantic tropical instability waves. J Geophys Res 117:C03011. doi:10.1029/2011JC007584 Google Scholar
  60. Peter AC, Le Hénaff M, duPenhoat Y, Menkes CE, Marin F, Vialard J, Caniaux G, Lazar A (2006) A model study of the seasonal mixed layer heat budget in the equatorial Atlantic. J Geophys Res 111:C06014. doi:10.1029/2005JC003157 Google Scholar
  61. Philander SGH, Pacanowski RC (1981) Response of equatorial oceans to periodic forcing. J Geophys Res 86(C3):1903–1916. doi:10.1029/JC086iC03p01903 CrossRefGoogle Scholar
  62. 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 CrossRefGoogle Scholar
  63. Picaut J, Masia F, duPenhoat Y (1997) An advective-reflective conceptual model for the oscillatory nature of the ENSO. Science 277(5326):663–666. doi:10.1126/science.277.5326.663 CrossRefGoogle Scholar
  64. Praveen Kumar B, Vialard J, Lengaigne M, Murty VSN, McPhaden MJ (2012) TropFlux: air-sea fluxes for the global tropical oceans—description and evaluation. Clim Dyn 38:1521–1543. doi:10.1007/s00382-011-1115-0 CrossRefGoogle Scholar
  65. Redelsperger JL, Diedhiou A, Flamant C, Janicot S, Lafore JP, Lebel T, Polcher J, Bourlès B, Caniaux G, De Rosnay P, Desbois M, Eymard L, Fontaine B, Geneau I, Ginoux K, Hoepffner M, Kane C, Law K, Mari C, Marticorena B, Mougin E, Pelon J, Peugeot C, Protat A, Roux F, Sultan B, Van Der Akker E (2006) Amma, une etude multidisciplinaire de la mousson oust-africaine. La Météorologie 54:22–32. doi:10.4267/2042/20098 CrossRefGoogle Scholar
  66. Reynolds RW, Smith TM, Liu C, Chelton DB, Casey KS, Schlax MG (2007) Daily high resolution blended analysis for sea surface temperature. J Clim 20:5473–5496. doi:10.1175/2007JCLI1824.1 CrossRefGoogle Scholar
  67. Rhein M, Dengler M, Sueltenfuss J, Hummels R, Huttl-Kabus S, Bourlès B (2010) Upwelling and associated heat flux in the equatorial Atlantic inferred from helium isotope disequilibrium. J Geophys Res: Oceans 115:C08021. doi:10.1029/2009JC005772 CrossRefGoogle Scholar
  68. Richter I, Behera SK, Masumoto Y, Taguchi B, Sasaki H, Yamagata T (2013) Multiple causes of interannual sea surface temperature variability in the equatorial Atlantic ocean. Nat Geosci 6(1):43–47. doi:10.1038/ngeo1660 Google Scholar
  69. Richter I, Behera SK, Doi T, Taguchi B, Masumoto Y, Xie SP (2014) What controls equatorial Atlantic winds in boreal spring? Clim Dyn 43(11):3091–3104. doi:10.1007/s00382-014-2170-0 CrossRefGoogle Scholar
  70. Saha S, Moorthi S, Thiaw C, Wang J, Nadiga S, Tripp P, Kistler R, Woollen J, Behringer D, Liu H, Stokes D, Grumbine R, Gayno G, Wang J, Hou Y-T, Chuang H-Y, Juang H-MH, Sela J, Iredell M, Treadon R, Kleist D, Van Delst P, Keyser D, Derber J, Ek M, Meng J, Wei H, Yang R, Lord S, Van Den Dool H, Kumar A, Wang W, Long C, Chelliah M, Xue Y, Huang B, Schemm J-K, Ebisuzaki W, Lin R, Xie P, Chen M, Zhou S, Higgins W, Zou C-Z, Liu Q, Chen Y, Han Y, Reynolds RW, Rutledge G, Goldberg M (2010) The ncep climate forecast system reanalysis. Bull Am Meteorol Soc 91:1015–3517. doi:10.1175/2010BAMS3001.1 CrossRefGoogle Scholar
  71. Schlundt M, Brandt P, Dengler M, Hummels R, Fischer T, Bumke K, Krahmann G, Karstensen J (2014) Mixed layer heat and salinity budgets during the onset of the 2011 Atlantic cold tongue. J Geophys Res: Oceans 119:7882–7910. doi:10.1002/2014JC010021 CrossRefGoogle Scholar
  72. Servain J, Picaut J, Merle J (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 CrossRefGoogle Scholar
  73. Suarez MJ, Schopf PS (1988) A delayed action oscillator for ENSO. J Atmos Sci 45(21):3283–3287. doi:10.1175/1520-0469(1988)045<3283:ADAOFE>2.0.CO;2 CrossRefGoogle Scholar
  74. Taylor KE (2001) Summarizing multiple aspects of model performance in a single diagram. J Geophys Res 107(D7):7183–7192. doi:10.1029/2000JD900719 CrossRefGoogle Scholar
  75. Voldoire A, Claudon M, Caniaux G, Giordani H, Roehrig R (2014) Are atmospheric biases responsible for the tropical Atlantic SST biases in CNRM-CM5 coupled model? Clim Dyn 43(11):2963–2984. doi:10.1007/s00382-013-2036-x CrossRefGoogle Scholar
  76. Wade M, Caniaux G, duPenhoat Y, Dengler M, Giordani H, Hummels R (2011a) A one-dimensional modeling study of the diurnal cycle in the equatorial Atlantic at the PIRATA buoys during the EGEE-3 campaign. Ocean Dyn 61(1):1–20. doi:10.1007/s10236-010-0337-8 CrossRefGoogle Scholar
  77. Wade M, Caniaux G, duPenhoat Y (2011b) Variability of the mixed layer heat budget in the eastern equatorial Atlantic during 2005–2007 as inferred using ARGO floats. J Geophys Res 116:C08006. doi:10.1029/2010JC006683 CrossRefGoogle Scholar
  78. Waliser DE, Gautier C (1993) A satellite-derived climatology of the ITCZ. J Clim 6:2162–2174. doi:10.1175/1520-0442(1993)006<2162:ASDCOT>2.0.CO;2 CrossRefGoogle Scholar
  79. Wauthy B (1983) Introduction à la climatologie du Golfe de Guinée. Océanographie Tropicale 18(2):103–138Google Scholar
  80. Weingartner TJ, Weisberg RH (1991) On the annual cycle of equatorial upwelling in the Central Atlantic Ocean. J Phys Oceanogr 21:68–82. doi:10.1175/1520-0485(1991)021<0068:OTACOE>2.0.CO;2 CrossRefGoogle Scholar
  81. Woodruff SD, Worley SJ, Lubker SJ, Ji Z, Freeman JE, Berry DI, Brohan P, Kent EC, Reynolds RW, Smith SR, Wilkinson C (2011) ICOADS Release 2.5: extensions and enhancements to the surface marine meteorological archive. Int J Climatol 31(7):951–967. doi:10.1002/joc.2103 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Yann Planton
    • 1
  • Aurore Voldoire
    • 1
  • Hervé Giordani
    • 1
  • Guy Caniaux
    • 1
  1. 1.CNRM-UMR3589, Météo-France/CNRS, CNRMToulouseFrance

Personalised recommendations