Satellite Observations of Oceanic Eddies Around Africa

Chapter

Abstract

Oceanic eddies having scales from several hundred meters to several hundred kilometers are ubiquitous phenomena in the World’s ocean. This became evident only after they could be observed from satellites and space shuttles. Here we present several images taken in different spectral bands which show signatures of eddies of different spatial scales in sea areas around Africa. In particular, we present a series of satellite images showing the propagation of a small-scale cyclonic (cold) eddy generated at Cap-Vert at the coast of Senegal into the open ocean. We show that this small-scale eddy transported nutrients from the Senegal upwelling region westward into the oligotrophic North Atlantic thus giving rise to enhanced chlorophyll-a concentration there. Since eddies are also areas of high fish population, knowledge of their position and properties is of great importance for fishery.

References

  1. Alpers W, Brandt P, Lazar A, Dagorne D, Sow B, Faye S, Hansen MW, Rubino A, Poulain PM, Brehmer P (2013) A small-scale oceanic eddy off the coast of West Africa studied by multi-sensor satellite and surface drifter data. Remote Sens Environ 129:132–143. doi: 10.1016/j.rse.2012.10.032CrossRefGoogle Scholar
  2. Alpers W, Espedal H (2004) Oils and Surfactants. In: Jackson CR, Apel JR (eds) Synthetic aperture radar marine user’s manual, chapter 11. NOAA/NESDIS, Washington, DC, pp 263–276. http://www.sarusersmanual.com/ManualPDF/NOAASARManual_CH11_pg263-276.pdf Google Scholar
  3. Alpers W, Hennings I (1984) A theory of the imaging mechanism of underwater bottom topography by real and synthetic aperture radar. J Geophys Res 89:10529–10546CrossRefGoogle Scholar
  4. Capet X, McWilliams JC, Molemaker MJ, Shchepetkin AF (2008) Mesoscale to submesoscale transition in the California Current System: I. Flow structure, eddy flux, and observational tests. J Phys Oceanogr 38:2256–2269CrossRefGoogle Scholar
  5. Chaigneau A, Eldin G, Dewitte B (2008) Eddy activity in the four major upwelling systems from satellite altimetry (1992–2007). Prog Oceanogr 83:117–123CrossRefGoogle Scholar
  6. Chelton DB, de Szoeke RA, Schlax MG, Naggar KE, Siwertz N (1998) Geographical variability of the first-baroclinic Rossby radius of deformation. J Phys Oceanogr 28:433–460CrossRefGoogle Scholar
  7. Chelton DB, Schlax MG, Samelson RM (2011) Global observations of nonlinear mesoscale eddies. Prog Oceanogr 91:167–216CrossRefGoogle Scholar
  8. Cox CC, Munk WH (1954) Measurement of the roughness of the sea surface from photography of the Sun’s glitter. J Opt Soc Am 44(11):838–850CrossRefGoogle Scholar
  9. Cresswell GR, Legeckis R (1986) Eddies off southeastern Australia. Deep-Sea Res 33:1527–1562CrossRefGoogle Scholar
  10. Davies PA, Dakin JM, Falconer RA (1995) Eddy formation behind a coastal headland. J Coastal Res 11:154–167Google Scholar
  11. Demarcq H (1998) Spatial and temporal dynamics of the upwelling off Senegal and Mauritania: local change and trend. In: Durand MH, Cury P, Mendelssohn R, Roy C, Bakun A, Pauly D (eds) Global versus local changes in upwelling systems: a report from the CEOS Workshop, Monterey, California, September 1994. ORSTOM Editions, Paris, pp 149–166. http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_7/divers2/010015307.pdf Google Scholar
  12. DiGiacomo PM, Holt B (2001) Satellite observations of small coastal ocean eddies in the Southern California Bight. J Geophys Res 106(C10):22521–22543CrossRefGoogle Scholar
  13. Eldevik T, Dysthe KB (2002) Spiral eddies. J Phys Oceanogr 32:851–869. doi: http://dx.doi.org/10.1175/1520-0485 CrossRefGoogle Scholar
  14. Espedal H, Johannessen OM, Johannessen JA, Dano E, Lyzenga D, Knulst JC (1998) COASTWATCH ’95: a tandem ERS-1/2 SAR detection experiment of natural film on the ocean surface. J Geophys Res 103:24969–24982CrossRefGoogle Scholar
  15. Falkowski PG, Ziemann DZ, Kolbera Z, Bienfang PK (1991) Role of eddy of pumping in enhancing primary production in the ocean. Nature 352:55–58, re 352:55–58, doi:10.1038/352055a0CrossRefGoogle Scholar
  16. Fu LL, Ferrari R (2008) Observing oceanic submesoscale processes from space. Eos 89(48):488–489CrossRefGoogle Scholar
  17. Fu LL, Holt B (1983) Some examples of detection of oceanic mesoscale eddies by the Seasat synthetic aperture radar. J Geophys Res 88:1844–1852CrossRefGoogle Scholar
  18. Golitsyn GS (2012) On the nature of spiral eddies on the surface of seas and oceans. Izvestiya AN. Fizika Atmosfery i Okeana 48:391–395Google Scholar
  19. Gower JFR, Denman KL, Holyer RL (1980) Phytoplankton patchiness indicates the fluctuations spectrum of mesoscale oceanic structure. Nature 288:157–159CrossRefGoogle Scholar
  20. Huehnerfuss H, Alpers W, Dannhauer H, Gade M, Lange PA, Neumann V, Wismann V (1996) Natural and man-made sea slicks in the North Sea, investigated by a helicopter-borne 5-frequency radar scatterometer. Int J Rem Sens 17:1567–1582CrossRefGoogle Scholar
  21. Ivanov AY, Ginzburg AI (2002) Oceanic eddies in synthetic aperture radar images. J Earth Syst Sci 111(3):281–295CrossRefGoogle Scholar
  22. Jackson CR, Alpers W (2010) The role of the critical angle in brightness reversals on sunglint images of the sea surface, J Geophys Res 115:C09019. doi:10.1029/2009JC006037Google Scholar
  23. Johannessen JA, Roed LP, Wahl T (1993) Eddies detected in ERS-1 SAR images and simulated in reduced gravity model. Int J Rem Sens 14:2203–2213CrossRefGoogle Scholar
  24. Johannessen JA, Shuchman RA, Digranes G, Lyzenga D, Wackerman C, Johannessen OM, Vachon PW (1996) Coastal ocean fronts and eddies imaged with ERS-1 synthetic aperture radar. J Geophys Res 101:6651–6667CrossRefGoogle Scholar
  25. Karimova S (2012) Spiral eddies in the Baltic, Black and Caspian seas as seen by satellite radar data. Adv Space Res 50(8):1107–1124. http://dx.doi.org/10.1016/j.asr.2011.10.027 CrossRefGoogle Scholar
  26. Kudryavtsev V, Akimov D, Johannessen JA, Chapron B (2005) On radar imaging of current features, part 1: model and comparison with observations. J Geophys Res 110:C07016Google Scholar
  27. Kusakabe M, Andreev A, Lobanov V, Zhabin I, Kumamoto Y, Murata A (2002) Effects of the anticyclonic eddies on water masses, chemical parameters and chlorophyll distributions in the Oyashio current region. J Oceanogr 58:691–701CrossRefGoogle Scholar
  28. Le Galloudec O, Bourdalle-Badie R, Drillet Y, Derval YC, Bricaud C (2008) Simulation of meso-scale eddies in the Mercator global ocean high resolution model. Mercator Newsl 3Google Scholar
  29. Lellouche JM et al. (2013) Evaluation of global monitoring and forecasting systems at Mercator Océan, Ocean Sci., 9, 57–81, doi:10.5194/os-9-57-2013Google Scholar
  30. Levy M, Klein P, Treguier AM (2001) Impact of sub-mesoscale physics on production and subduction of phytoplankton in an oligotrophic regime. J Mar Res 59:535–565CrossRefGoogle Scholar
  31. Lin II, Lien CC, Wu CR, George TF, Wong GTF, Huang CW, Chiang TL (2010) Enhanced primary production in the oligotrophic South China Sea by eddy injection. Geophys Res Lett 37:L16602. doi:10.1029/2010GL043872Google Scholar
  32. Maltrud ME, McClean JL (2005) An eddy resolving global 1/10° ocean simulation. Ocean Model 8(1–2):31–54CrossRefGoogle Scholar
  33. McWilliams JC (1985) Submesoscale, coherent vortices in the ocean. Rev Geophys 23:165–182CrossRefGoogle Scholar
  34. Morrow R, Fang F, Fieux M, Molcard R (2003) Anatomy of three warm-core Leeuwin current eddies. Deep-Sea Res Pt II 50:2229–2243CrossRefGoogle Scholar
  35. Munk W, Armi I, Fischer K, Zachariasen F (2000) Spirals on the sea. Proc R Soc Lon Ser-A 456:1217–1280CrossRefGoogle Scholar
  36. Olson DB (1991) Rings in the ocean. Annu Rev Earth Planet Sci 19:283–311CrossRefGoogle Scholar
  37. Pattiaratchi C, James A, Collins M (1987) Island wakes and headland eddies: a comparison between remotely sensed data and laboratory experiments. J Geophys Res 92:783–794CrossRefGoogle Scholar
  38. Scully-Power P (1986) Navy oceanographer shuttle observations, STS 41-G, mission report. Naval Underwater Systems Center Tech. Rep. NUSC TD 7611Google Scholar
  39. Siegel A, Weiss JB, Toomre J, McWilliams JC, Berloff PS, Yavneh I (2001) Eddies and vortices in ocean basin dynamics. Geophys Res Lett 28:3183–3186CrossRefGoogle Scholar
  40. Signell RP, Geyer WR (1991) Transient eddy formation around headlands. J Geophys Res 96:2561–2575CrossRefGoogle Scholar
  41. Siokou-Frangou J et al (2010) Plankton in the open Mediterranean Sea: a review. Biogeosciences 7:1543–1586CrossRefGoogle Scholar
  42. Soules SD (1970) Sun glitter viewed from space. Deep-Sea Res 17:191–195Google Scholar
  43. Stevenson RE (1998) Spiral eddies: the discovery that changed the face of the oceans. 21st Cent Sci Technol 11:58–71Google Scholar
  44. Thomas, LN, Tandon A, Mahadevan A (2008) Submesoscale processes and dynamics. In Hecht M. and Hasumi H., editors, Ocean Modeling in an Eddying Regime, (AGU Monograph), American Geophysical Union, Washington DC, pages 17–38, 2008Google Scholar
  45. Valenzuela GR (1978) Theories for the interaction of electromagnetic and ocean waves—a review. Bound Lay Meteorol 13:61–85CrossRefGoogle Scholar
  46. Wang S, Tang D (2010) Remote sensing of day/night sea surface temperature difference related to phytoplankton bloom. Int J Rem Sens 31:4569–4578CrossRefGoogle Scholar
  47. Williams RG (2011) Ocean eddies and plankton blooms. Nat Geosci 4:739–740CrossRefGoogle Scholar
  48. Yamaguchi S, Kawamura H (2009) SAR-imaged spiral eddies in Mutsu Bay and their dynamic and kinematic models. J Phys Oceanogr 65(4):525–539CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • Werner Alpers
    • 1
  • Dominique Dagorne
    • 2
  • Peter Brandt
    • 3
  1. 1.Institut für MeereskundeUniversität of HamburgHamburgGermany
  2. 2.US ImagoInstitut de Recherche pour le DéveloppementPlouzanéFrance
  3. 3.GEOMAR Helmholtz-Zentrum für Ozeanforschung KielKielGermany

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