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Characterization and implications of intradecadal variations in length of day


Variations in Earth's rotation (defined in terms of length of day) arise from external tidal torques, or from an exchange of angular momentum between the solid Earth and its fluid components1. On short timescales (annual or shorter) the non-tidal component is dominated by the atmosphere, with small contributions from the ocean and hydrological system. On decadal timescales, the dominant contribution is from angular momentum exchange between the solid mantle and fluid outer core. Intradecadal periods have been less clear and have been characterized by signals with a wide range of periods and varying amplitudes, including a peak at about 6 years (refs 2, 3, 4). Here, by working in the time domain rather than the frequency domain, we show a clear partition of the non-atmospheric component into only three components: a decadally varying trend, a 5.9-year period oscillation, and jumps at times contemporaneous with geomagnetic jerks. The nature of the jumps in length of day leads to a fundamental change in what class of phenomena may give rise to the jerks, and provides a strong constraint on electrical conductivity of the lower mantle, which can in turn constrain its structure and composition.

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Figure 1: Fit to ΔLOD data (black line) of 5.9-year oscillation and decadal trend (grey line).
Figure 2: Decadally detrended LOD data (with 6-month running average), plotted with 5.9-year oscillation fit (dashed line).
Figure 3: Focus on 1965–1985 to show correlation between the 5.9-year LOD oscillation and a histogram of wavelet-determined geomagnetic jerk occurrence times10.
Figure 4: Focus on 2002–2006 to compare LOD series with well-constrained geomagnetic jerk times (long vertical dashes; short dashes mark 3 months each side of these times).


  1. Gross, R. S. in Treatise on Geophysics, Vol. 3 (ed. Herring, T. A. ) Ch. 9, 107–130 (Elsevier, 2007)

    Google Scholar 

  2. Vondrak, J. The rotation of the Earth between 1955.5 and 1976.5. Stud. Geophys. Geod. 21, 107–117 (1977)

    Article  ADS  Google Scholar 

  3. Liao, D. C. & Greiner-Mai, H. A new DELTA LOD series in monthly intervals (1892.0–1997.0) and its comparison with other geophysical results. J. Geod. 73, 466–477 (1999)

    Article  ADS  Google Scholar 

  4. Abarco del Rio, R., Gambis, D. & Salstein, D. A. Interannual signals in length of day and atmospheric angular momentum. Ann. Geophys. 18, 347–364 (2000)

    Article  ADS  Google Scholar 

  5. Gorshov, V. L. Study of the interannual variations of the Earth's rotation. Sol. Syst. Res. 44, 487–497 (2010)

    Article  ADS  Google Scholar 

  6. Gillet, N., Jault, D., Canet, E. & Fournier, A. Fast torsional waves and strong magnetic field within the earth's core. Nature 465, 74–77 (2010)

    Article  ADS  CAS  Google Scholar 

  7. Abarco del Rio, R., Gambis, D., Salstein, D. A., Nelson, P. & Daid, A. Solar activity and earth rotation variability. J. Geodyn. 36, 423–443 (2003)

    Article  Google Scholar 

  8. Mound, J. E. & Buffett, B. A. Detection of a gravitational oscillation in length-of-day. Earth Planet. Sci. Lett. 243, 383–389 (2006)

    Article  ADS  CAS  Google Scholar 

  9. Mandea, M., Pais, R. H. A., Pinheiro, K., Jackson, A. & Verbanac, G. Geomagnetic jerks: rapid core field variations and core dynamics. Space Sci. Rev. 155, 147–175 (2010)

    Article  ADS  CAS  Google Scholar 

  10. Alexandrescu, M. M., Gibert, D., Hulot, G., Le Mouël, J.-L. & Saracco, G. Worldwide wavelet analysis of geomagnetic jerks. J. Geophys. Res. 101, 21,975–21,994 (1996)

    Article  ADS  Google Scholar 

  11. Pinheiro, K., Jackson, A. & Finlay, C. C. Measurements and uncertainties of the occurrence time of the 1969, 1978, 1991, and 1999 geomagnetic jerks. Geochem. Geophys. Geosyst. 12, Q10015 (2011)

    Article  ADS  Google Scholar 

  12. Pinheiro, K. & Jackson, A. Can a 1-d mantle electrical conductivity model generate magnetic jerk differential time delays? Geophys. J. Int. 173, 781–792 (2008)

    Article  ADS  CAS  Google Scholar 

  13. Holme, R. & de Viron, O. Geomagnetic jerks and a high-resolution length-of-day profile for core studies. Geophys. J. Int. 160, 435–439 (2005)

    Article  ADS  Google Scholar 

  14. Olsen, N. & Mandea, M. Rapidly changing flows in the Earth’s core. Nature Geosci. 1, 390–394 (2008)

    Article  ADS  CAS  Google Scholar 

  15. Gross, R. S. & Chao, B. F. The rotational and gravitational signature of the December 26, 2004 Sumatran earthquake. Surv. Geophys. 27, 615–632 (2006)

    Article  ADS  Google Scholar 

  16. Holme, R. Magnetic ringing of the Earth. Nature 459, 652–653 (2009)

    Article  ADS  CAS  Google Scholar 

  17. Bloxham, J. The expulsion of magnetic flux from the Earth’s core. Geophys. J. R. Astron. Soc. 87, 669–678 (1986)

    Article  ADS  Google Scholar 

  18. Bloxham, J., Zatman, S. & Dumberry, M. The origin of geomagnetic jerks. Nature 420, 65–68 (2002)

    Article  ADS  CAS  Google Scholar 

  19. Wardinski, I., Holme, R., Asari, S. & Mandea, M. The 2003 geomagnetic jerk and its relation to the core surface flows. Earth Planet. Sci. Lett. 267, 468–481 (2008)

    Article  ADS  CAS  Google Scholar 

  20. Benton, E. R. & Whaler, K. A. Rapid diffusion of the poloidal geomagnetic field through the weakly conducting mantle: a perturbation solution. Geophys. J. R. Astron. Soc. 75, 77–100 (1983)

    Article  ADS  Google Scholar 

  21. Backus, G. E. Application of mantle filter theory to the magnetic jerk of 1969. Geophys. J. R. Astron. Soc. 74, 713–746 (1983)

    Google Scholar 

  22. Holme, R. in The Core–Mantle Boundary Region (eds Gurnis, M., Wysession, M. E., Knittle, E. & Buffett, B. A. ) 139–151 (American Geophysical Union, 1998)

    Book  Google Scholar 

  23. Buffett, B. A. Constraints on magnetic energy and mantle conductivity from the forced nutations of the Earth. J. Geophys. Res. 97, 19581–19597 (1992)

    Article  ADS  Google Scholar 

  24. Olsen, N. Long-period (30 days – 1 year) electromagnetic sounding and the electrical conductivity of the lower mantle beneath Europe. Geophys. J. Int. 138, 179–187 (1999)

    Article  ADS  Google Scholar 

  25. Velimsky, J. Electrical conductivity in the lower mantle: constraints from CHAMP satellite data by time-domain EM induction modelling. Phys. Earth Planet. Inter. 180, 111–117 (2010)

    Article  ADS  Google Scholar 

  26. Ono, S., Oganov, A. R., Koyama, T. & Shimizu, H. Stability and compressibility of the high-pressure phases of Al2O3 up to 200 GPa: implications for the electrical conductivity of the base of the lower mantle. Earth Planet. Sci. Lett. 246, 326–335 (2006)

    Article  ADS  CAS  Google Scholar 

  27. Hernland, J. W., Thomas, C. & Tackley, P. J. A doubling of the post-perovskite phase boundary and structure of the Earth’s lowermost mantle. Nature 434, 882–886 (2005)

    Article  ADS  Google Scholar 

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O.d.V. was supported by Centre National d’Études Spatiales (CNES) through the TOSCA (Terre, Océan, Surfaces Continentales, Atmosphère) programme, and by the French Institut Universitaire de France. The oceanographic model used is a contribution of the Consortium for Estimating the Circulation and Climate of the Ocean (ECCO) funded by the National Oceanographic Partnership Program.

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R.H. performed the primary analysis and led the writing of the manuscript. O.d.V. provided the original data with corrections for atmosphere and ocean, and contributed to writing the manuscript.

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Correspondence to R. Holme.

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Holme, R., de Viron, O. Characterization and implications of intradecadal variations in length of day. Nature 499, 202–204 (2013).

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