Special Issue: Swarm—The Earth’s Magnetic Field and Environment Explorers
- Open Access
Ocean circulation generated magnetic signals
Earth, Planets and Space volume 58, pages 429–437 (2006)
Conducting ocean water, as it flows through the Earth’s magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification of ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume an Earth’s conductivity model with a surface thin shell of variable conductance with a realistic 1D mantle underneath. Simulations using both models predict an amplitude range of ±2 nT at Swarm altitude (430 km). However at sea level, the higher resolution simulation predicts a higher strength of the magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals.
Chave, A., On the theory of electromagnetic induction in the earth by ocean currents, J. Geophys. Res., 88, 3531–3542, 1983.
Everett, M., S. Constable, and C. Constable, Effects of near-surface conductance on global satellite induction responses, Geophys. J. Int., 153, 277–286, 2003.
Faraday, M., Experimental researches in electricity (Bakerian lecture), Philos. Trans. R. Soc. London, 122, 163–177, 1832.
Flosadóttir, A. H., J. C. Larsen, and J. T. Smith, Motional induction in North Atlantic circulation models, J. Geophys. Res., 102, 10,353–10,372, 1997a.
Flosadóttir, A. H., J. C. Larsen, and J. T. Smith, The relation of seafloor voltages to ocean transports in North Atlantic circulation models: Model results and practical considerations for transport monitoring, J. Physical Oceanography, 27, 1547–1565, 1997b.
Fofonoff, N. P., Physical properties of seawater: A new salinity scale and equation of state for seawater, J. Geophys. Res., 90, 3322–3342, 1985.
Junge, A., The telluric field in northern Germany induced by tidal motion in North Sea, Geophys. J. Int., 95, 523–533, 1988.
Kuvshinov, N. and N. Olsen, 3-D modelling of the magnetic fields due to ocean tidal flow, in Earth Observation with CHAMP. Results from Three Years in Orbit, edited by C. Reigber, H. Lühr, P. Schwintzer, and J. Wickert, pp. 359–366, Springer Verlag, 2005.
Kuvshinov, A. V., D. B. Avdeev, O. V. Pankratov, S. A. Golyshev, and N. Olsen, Modelling electromagnetic fields in 3D spherical Earth using fast integral equation approach, in 3D Electromagnetics, edited by M. S. Zhdanov, and P. E. Wannamaker, chap. 3, pp. 43–54, Elsevier, Holland, 2002.
Kuvshinov, A. V., H. Utada, D. Avdeev, and T. Koyama, 3-D modelling and analysis of Dst C-responses in the North Pacific Ocean region, revisited, Geophys. J. Int., 160, 505–526, 2005.
Larsen, J. C., Electric and magnetic fields induced by deep see tides, Geophys. J. R. Astr. Soc., 16, 47–70, 1968.
Larsen, J. C. and T. Sanford, Florida Current volume transport from voltage measurements, Science, 227, 302–304, 1985.
Laske, G. and G. Masters, A global digital map of sediment thickness, EOS Trans. AGU, 78, F483, 1997.
Lilley, F., A. White, G. Heinson, and K. Procko, Seeking a seafloor magnetic signal from the Antarctic Circumpolar Current, Geophys. J. Int., 157, 175–186, 2004a.
Lilley, F., A. Hitchman, P. R. Milligan, and T. Pedersen, Sea-surface observations of the magnetic signals of ocean swells, Geophys. J. Int., 159, 565–572, 2004b.
Marshall, J., A. Adcroft, C. Hill, Perelman, and C. Heisey, A finite-volume, incompressible Navier-Stokes model for studies of the ocean on parallel computers, J. Geophys. Res., 102, 5753–5766, 1997.
Maus, S. and A. Kuvshinov, Ocean tidal signals in observatory and satellite magnetic measurements, Geophyc. Res. Lett, 31, doi:10.1029/2004GC000, 634, 2004.
Maus, S., M. Rother, K. Hemant, H. Lühr, A. Kuvshinov, and N. Olsen, Earth’s crustal magnetic field determined to spherical harmonic degree 90 from CHAMP satellite measurements, Geophys. J. Int., 164, 319–330, doi:10.1111/j.1365-246X.2005.02833.x, 2006.
Palshin, N., L. Vanyan, I. Yegorov, and K. Lebedev, Electric field induced by the glodal ocean circulation, Physics Solid Earth, 35, 1028–1035, 1999.
Pankratov, O., A. Kuvshinov, and D. Avdeev, High-performance three-dimensional electromagnetic modeling using modified Neumann series. Anisotropic case, J. Geomag. Geoelectr., 49, 1541–1547, 1997.
Sanford, T. B., Motionally induced electric and magnetic fields in the sea, J. Geophys. Res., 76, 3476–3492, 1971.
Schmucker, U., Electrical properties of the Earth’s interior, in Landolt-Börnstein, New-Series, 5/2b, pp. 370–397, Springer-Verlag, Berlin-Heidelberg, 1985.
Singer, B., Method for solution of Maxwell’s equations in non-uniform media, Geophys. J. Int., 120, 590–598, 1995.
Stephenson, D. and K. Bryan, Large-scale electric and magnetic fields generated by the oceans, J. Geophys. Res., 97, 15,467–15,480, 1992.
Tyler, R. H., Theoretical and Numerical Results on the Magnetic Fields Generated by Ocean Flow, EGS annual conference, 2002.
Tyler, R. H., Exploring and exploiting the magnetic fields generated by ocean flow, Geophysical Research Abstracts, 5, 2003.
Tyler, R., L. A. Mysak, and J. Oberhuber, Electromagnetic fields generated by a 3-D global ocean circulation, J. Geophys. Res., 102, 5531–5551, 1997.
Tyler, R. H., T. B. Sanford, and J. M. Oberhuber, Magnetic Fields Generated by Ocean Flow, AGU Fall Conference, 1998.
Tyler, R., J. Oberhuber, and T. Sanford, The potential for using ocean generated electromagnetic field to remotely sense ocean variability, Phys. Chem. Earth (A), 24, 429–432, 1999.
Tyler, R., S. Maus, and H. Lühr, Satellite observations of magnetic fields due to ocean tidal flow, Science, 299, 239–240, 2003.
Vivier, F., E. Maier-Reimer, and R. H. Tyler, Simulations of magnetic fields generated by the Antarctic Circumpolar Current at satellite altitude: Can geomagnetic measurements be used to monitor the flow?, Geophys. Res. Lett., 31, doi:10.1029/2004GL019, 804, 2004.
Webb, D. J., B. A. de Cuevas, and A. C. Coward, The first main run of the OCCAM global ocean model, Internal Document 34, Southampton Oceanography Centre, U.K., 1998.
Zhang, S.-L., GPBi-CG: generalized product-type methods based on Bi-CG for solving nonsymmetric linear systems, SIAM J. Sci. Comput., 18, 537–551, 1997.
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Manoj, C., Kuvshinov, A., Maus, S. et al. Ocean circulation generated magnetic signals. Earth Planet Sp 58, 429–437 (2006). https://doi.org/10.1186/BF03351939
- Ocean flow
- geomagnetic field
- satellite measurements