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A magnetically driven equatorial jet in Europa’s ocean

Nature Astronomy (2019) | Download Citation


During recent decades, data from space missions have provided strong evidence of deep liquid oceans underneath a thin outer icy crust on several moons of Jupiter1,2, particularly Europa3,4. But these observations have also raised many unanswered questions regarding the oceanic motions generated under the ice, or the mechanisms leading to the geological features observed on Europa5,6. By means of direct numerical simulations of Europa’s interior, we show here that Jupiter’s magnetic field generates a retrograde oceanic jet at the equator, which may influence the global dynamics of Europa’s ocean and contribute to the formation of some of its surface features by applying a unidirectional torque on Europa’s ice shell.

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The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

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  1. 1.

    Neubauer, F. M. Oceans inside Jupiter’s moons. Nature 395, 749–750 (1998).

  2. 2.

    Khurana, K. K. et al. Induced magnetic fields as evidence for subsurface oceans in Europa and Callisto. Nature 395, 777–780 (1998).

  3. 3.

    Sparks, W. B. et al. Transient water vapor at Europa’s south pole. Science 343, 171–174 (2014).

  4. 4.

    Roth, L. et al. Active cryovolcanism on Europa. Astrophys. J. Lett. 839, L18 (2017).

  5. 5.

    Pappalardo, R. T. et al. A Europan ocean? The (circumstantial) geological evidence. In Proc. Europa Ocean Conf. 59–60 (San Juan Capistrano Research Institute, 1996)..

  6. 6.

    Pappalardo, R. T. et al. Does Europa have a subsurface ocean? Evaluation of the geological evidence. J. Geophys. Res. 104, 24015–24055 (1999).

  7. 7.

    Thomson, R. E. & Delaney, J. R. Evidence for a weakly stratified Europan ocean sustained by seafloor heat flux. J. Geophys. Res. 106, 355–365 (2001).

  8. 8.

    Ross, M. N. & Schubert, G. et al. Tidal heating in an internal ocean model of Europa. Nature 325, 133–134 (1987).

  9. 9.

    Spohn, T. & Schubert, G. Oceans in the icy Galilean satellites of Jupiter. Icarus 161, 456–467 (2003).

  10. 10.

    Bills, B. G. Free and forced obliquities of the Galilean satellites of Jupiter. Icarus 175, 233–245 (2005).

  11. 11.

    Tyler, R. H. Strong ocean tidal flow and heating on moons of the outer planets. Nature 456, 770–773 (2008).

  12. 12.

    Soderlund, K. M., Schmidt, B. E., Wicht, J. & Blankenship, D. D. Ocean-driven heating of Europa’s icy shell at low latitudes. Nat. Geosci. 7, 16–19 (2014).

  13. 13.

    Goodman, J. C., Collins, G. C., Marshall, J. & Pierrehumbert, R. T. Hydrothermal plume dynamics on europa: implications for chaos formation. J. Geophys. Res. 109, E03008 (2004).

  14. 14.

    Goodman, J. C. & Lenferink, E. Numerical simulations of marine hydrothermal plumes for Europa and other icy worlds. Icarus 221, 970–983 (2012).

  15. 15.

    Vance, S. & Brown, J. M. Layering and double-diffusion style convection in Europa’s ocean. Icarus 177, 506–514 (2005).

  16. 16.

    Colburn, D. S. & Reynolds, R. T. Electrolytic currents in Europa. Icarus 63, 39–44 (1985).

  17. 17.

    Gailitis, A. & Lielausis, O. Instability of homogeneous velocity distribution in an induction-type MHD machine. Magnetohydrodynamics 11, 69–79 (1976).

  18. 18.

    Reddy, K. S., Fauve, S. & Gissinger, C. Instabilities of MHD flows driven by traveling magnetic fields. Phys. Rev. Fluids 3, 063703 (2018).

  19. 19.

    Schilling, N., Neubauer, F. M. & Saur, J. Time-varying interaction of Europa with the Jovian magnetosphere: constraints on the conductivity of Europa’s subsurface ocean. Icarus 192, 41–55 (2007).

  20. 20.

    Hand, K. P. & Chyba, C. F. Empirical constraints on the salinity of the Europan ocean and implications for a thin ice shell. Icarus 189, 424–438 (2007).

  21. 21.

    Campagne, A. et al. Turbulent drag in a rotating frame. J. Fluid. Mech. 794, R5 (2016).

  22. 22.

    Greenberg, M. Transport rates of radiolytic substances into Europa’s ocean: implications for the potential origin and maintenance of life. Astrobiology 10, 3 (2010).

  23. 23.

    Sparks, W. B. et al. Probing for evidence of plumes on Europa with HST/STIS. Astrophys. J. 829, 121 (2016).

  24. 24.

    Greenberg, M. & Weidenshilling, S. How fast do Galilean satellites spin? Icarus 58, 186–196 (1984).

  25. 25.

    Ojakangas, G. W. & Stevenson, D. J. Polar wander of an ice shell on Europa. Icarus 81, 242–270 (1989).

  26. 26.

    Helfenstein, P. & Parmentier, E. M. Patterns of fracture and tidal stresses due to non-synchronous rotation: implications for fracturing on Europa. Icarus 61, 175–184 (1985).

  27. 27.

    Geissler, P. et al. Evidence for non-synchronous rotation of Europa. Nature 391, 368–370 (1998).

  28. 28.

    Schenk, P., Matsuyama, I. & Nimmo, F. True polar wander on Europa from global-scale small-circle depressions. Nature 453, 368–371 (2008).

  29. 29.

    Grasset, O. et al. JUpiter ICy moons Explorer (JUICE): an ESA mission to orbit Ganymede and to characterise the Jupiter system. Planet. Space Sci. 78, 1–21 (2013).

  30. 30.

    Phillips, C. B. & Pappalardo, R. T. Europa Clipper mission concept: exploring Jupiter’s ocean moon. EOS 95, 165–167 (2014).

  31. 31.

    Christensen, U. R. et al. A numerical dynamo benchmark. Phys. Earth Planet. Inter. 128, 25–34 (2001).

  32. 32.

    Dormy, E., Cardin, P. & Jault, D. MHD flow in a slightly differentially rotating spherical shell, with conducting inner core, in a dipolar magnetic field. Earth Planet. Sci. Lett. 160, 15–30 (1998).

  33. 33.

    Zimmer, C., Khurana, K. K. & Kivelson, M. G. Subsurface oceans on Europa and Callisto: constraints from Galileo magnetometer observations. Icarus 147, 329–347 (2000).

  34. 34.

    Gissinger, C., Rodriguez-Imazio, P. & Fauve, S. Instabilities in electromagnetically-driven flows, part I. Phys. Fluids 28, 034101 (2016).

  35. 35.

    Vance, S. & Goodman, J. C. in Europa (eds Pappalardo, R. T., McKinnon, W. M. & Khurana, K. K.) 459–482 (Univ. Arizona Press, 2009).

  36. 36.

    Kivelson, M. G. et al. Europa’s magnetic signature: Report from Galileoa’s pass on 19 December 1996. Science 276, 1239–1241 (1997).

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The GO-J-MAG-3-RDR-HIGHRES-V1.02 dataset was obtained from the Planetary Data System. This work was granted access to the HPC resources of MesoPSL financed by the Region Ile de France and the project Equip@Meso (reference ANR-10-EQPX-29-01) of the programme Investissements d’Avenir supervised by the Agence Nationale pour la Recherche.

Author information

Author notes

  1. These authors contributed equally: Christophe Gissinger, Ludovic Petitdemange.


  1. Laboratoire de Physique de l’Ecole Normale Superieure, ENS, Université PSL, CNRS, Paris, France

    • Christophe Gissinger
  2. LERMA, CNRS, Paris, France

    • Ludovic Petitdemange


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C.G. conceived the presented idea and developed the theory. L.P. performed the numerical simulations. C.G. and L.P. performed the analysis of the results and contributed to the final manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Christophe Gissinger.

Supplementary information

  1. Supplementary Information

    Supplementary Table 1, Supplementary Figures 1–3.

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