A magnetically driven equatorial jet in Europa’s ocean

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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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Fig. 1: Velocity field and ohmic currents.
Fig. 2: Galileo magnetometer data in the EPhiO coordinates (Europa-centred with x along the direction of corotation, y radially inward towards Jupiter, and z parallel to Jupiter’s rotation axis), compared with results from DNS using h = 147 km.
Fig. 3: Magnitude of the oceanic jet.
Fig. 4: Snapshot of the instantaneous azimuthal velocity field at r = Ri + h/2 from the seafloor, for Ek = 10−5, Pr = 12, Pm = 10−3, Λ = 10−3 and Ra = 109.

Data availability

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

Change history

  • 24 April 2019

    In the version of this Letter originally published, the following ‘Journal peer review information’ was missing: “Nature Astronomy thanks Jason Goodman and the other anonymous reviewer(s) for their contribution to the peer review of this work.” This statement has now been added.


  1. 1.

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

    ADS  Article  Google Scholar 

  2. 2.

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

    ADS  Article  Google Scholar 

  3. 3.

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

    Article  Google Scholar 

  4. 4.

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

    Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  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).

    Google Scholar 

  8. 8.

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

    ADS  Article  Google Scholar 

  9. 9.

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

    ADS  Article  Google Scholar 

  10. 10.

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

    ADS  Article  Google Scholar 

  11. 11.

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

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  14. 14.

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

    ADS  Article  Google Scholar 

  15. 15.

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

    ADS  Article  Google Scholar 

  16. 16.

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

    ADS  Article  Google Scholar 

  17. 17.

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

    Google Scholar 

  18. 18.

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

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  21. 21.

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

    Article  Google Scholar 

  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).

    Article  Google Scholar 

  23. 23.

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

    ADS  Article  Google Scholar 

  24. 24.

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

    ADS  Article  Google Scholar 

  25. 25.

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

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  27. 27.

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

    ADS  Article  Google Scholar 

  28. 28.

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

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  30. 30.

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

    ADS  Article  Google Scholar 

  31. 31.

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

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

  34. 34.

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

    ADS  Article  Google Scholar 

  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).

    ADS  Article  Google Scholar 

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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.

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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.

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Correspondence to Christophe Gissinger.

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The authors declare no competing interests.

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Journal peer review information: Nature Astronomy thanks Jason Goodman and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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Supplementary Information

Supplementary Table 1, Supplementary Figures 1–3.

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Gissinger, C., Petitdemange, L. A magnetically driven equatorial jet in Europa’s ocean. Nat Astron 3, 401–407 (2019). https://doi.org/10.1038/s41550-019-0713-3

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