Advertisement

Journal of Geodesy

, Volume 84, Issue 1, pp 19–30 | Cite as

Atmospheric and oceanic forcing of the rapid polar motion

  • Christian BizouardEmail author
  • L. Seoane
Original Article

Abstract

The rapid polar motion for periods below 20 days is revisited in light of the most recent and accurate geodetic and geophysical data. Although its amplitude is smaller than 2 mas, it is excited mostly by powerful atmospheric processes, as large as the seasonal ones. The residual amplitude, representing about 20% of the total excitation, stems from the oceans. Rapid polar motion has an irregular nature that is well explained by the combined influence of the atmosphere and the oceans. An overall spectrum reveals cycles principally at 20, 13.6 (fortnightly tidal period) and 10 days (corresponding to the normal atmospheric mode \({\Psi_3^1}\)), but this is only an averaged feature hiding its strong variability over seasonal time scales. This explains why it is so delicate to determine an empirical model of the tidal effect on polar motion. The variability in both amplitude and phase of the 13.6-day term is probably caused by a lunar barometric effect, modulated by some sub-seasonal thermal processes. The irregularities of the prominent cycles of the short-term polar motion are well explained by the atmospheric and oceanic excitations. The oceanic variability reinforces the atmospheric one, as they were triggered by the same agent, maybe seasonal and inter-annual thermal variations.

Keywords

Earth rotation Rapid polar motion Atmosphere Oceans Excitation Lunar tide 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Allan D (1987) Time and frequency (time-domain) characterisation, estimation, and prediction of precision clocks and oscillators. IEEE Trans Ultrason Ferroelectr Freq Control 34: 647–654CrossRefGoogle Scholar
  2. Arabelos D, Asteriadis G, Contadakis ME, Spatalas SD, Sachsamanoglou H (1997) Atmospheric tides in the area of Thessaloniki. J Geodyn 23(1): 65–75CrossRefGoogle Scholar
  3. Arabelos D, Asteriadis G, Bloutsos A, Contadakis ME, Spatalas SD (2004) Atmospheric tides disturbances as earthquake precursory phenomena. Nat Hazards Earth Syst Sci 4: 1–7CrossRefGoogle Scholar
  4. Barnes RTH, Hide R, White AA, Wilson CA (1983) Atmospheric angular momentum fluctuations, length-of-day changes and polar motion. Proc R Soc Lond A 387: 31–73CrossRefGoogle Scholar
  5. Bizouard C, Gambis D (2008) The combined solution C04 for Earth orientation parameters, recent improvements. In: Drewes H (ed) Springer Verlag Series on International Association of Geodesy Symposia 134. 330 p, ISBN 978-3-642-00859-7Google Scholar
  6. Brzeziński A (1987) Statistical investigations on atmospheric angular momentum functions and on their effects on polar motion. Manuscr Geodetica 12: 268–811Google Scholar
  7. Brzeziński A (1994) Polar motion excitation by variations of the effective angular momentum function, II: E xtended model. Manuscr Geodetica 19: 157–171Google Scholar
  8. Brzeziński A, Bizouard C, Petrov S (2002) Influence of the atmosphere on Earth rotation: what new can be learnt from the recent atmospheric angular momentum estimates?. Surv Geophys 23: 33–69CrossRefGoogle Scholar
  9. Dickamn S (1993) Dynamic ocean-tide effects on Earth’s rotation. Geophys J Int 112: 448–470CrossRefGoogle Scholar
  10. Eubanks TM, Steppe JA, Dickey JO (1986) The atmospheric excitation of Earth orientation changes during MERIT. In: Proceedings of the international conference on Earth rotation and the terrestrial reference frame, 1985, Ohio State University, Columbus, pp 469–483Google Scholar
  11. Eubanks TM, Steppe JA, Dickey JO, Rosen RD, Salstein DA (1988) Causes of rapid motions of the Earth’s pole. Nature 334: 115–119CrossRefGoogle Scholar
  12. Gambis D, Biancale R, Carlucci T, Lemoine JM, Marty JC, Bourda G, Charlot P, Loyer S, Lalanne L, Soudarin L (2009) Combination of Earth orientation parameters and terrestrial frame at the observation level. In: Drewes H (ed) Springer Verlag Series on International Association of Geodesy Symposia 134, 330 p, ISBN 978-3-642-00859-7Google Scholar
  13. Gross R, Lindqwister U (1992) Atmospheric excitation of polar motion during the GIG’91 measurement campaign. Geophys Res Lett 19(9): 849–852CrossRefGoogle Scholar
  14. Gross R, Chao BF, Desai S (1998) Effect of long-period ocean tides on the Earth’s polar motion. Prog Oceanogr 40(1-4): 385–397CrossRefGoogle Scholar
  15. Gross R, (2009) An improved empirical model for the effect of the long period ocean-tides on polar motion. J Geod 83:635–644. doi: 10.1007/s00190-008-0277-y Google Scholar
  16. IERS Conventions (2003) IERS Technical Note No 32, Ed. DD McCarthy and G Petit, p 125Google Scholar
  17. Kouba J (2005) Comparison of polar motion with oceanic and atmospheric angular momentum time series for 2-day to Chandler periods. J Geod 79(1-3):33–42. doi: 10.1007/s00190-005-0440-7 Google Scholar
  18. Lambert S, Bizouard C, Dehant V (2006) Rapid variations in polar motion during the 2005–2006 winter season. Geophys Res Lett 33: L13303CrossRefGoogle Scholar
  19. Li G (2005) 27.3 day and 13.6 day atmospheric tide and lunar forcing on atmospheric circulation. Adv Atmos Sci 22(3): 359–374CrossRefGoogle Scholar
  20. Nastula J, Gambis D, Feissel M (1990) Correlated high frequency variations in polar motion and of the length of the day in early 1988. Ann Geophys 8: 565–570Google Scholar
  21. Nastula J, Kosek W, Kolaczek B (1997) Analyses of zonal atmospheric excitation functions and their correlation with polar motion excitation functions. Ann Geophys 15(11): 1439–1446CrossRefGoogle Scholar
  22. Nastula J, Ponte R (1999) Further evidence for oceanic excitation of polar motion. Geophys J Int 139(1): 123–130CrossRefGoogle Scholar
  23. Petrov S (1998) Modeling excitation of Earth rotation: stochastic and nonlinear approaches. PhD thesis, Space Research Centre of the Polish Academy of Science, Warsaw, PolandGoogle Scholar
  24. Ponte R, Ali A (2002) Rapid ocean signals in polar motion and length of day. Geophys Res Lett 29(15): 6CrossRefGoogle Scholar
  25. Salstein D, Rosen R (1989) Regional contributions to the atmospheric excitation of rapid polar motions. J Geophys Res 94(D7): 9971–9978CrossRefGoogle Scholar
  26. SBA (2009) WEB site of the IERS Special Bureau for the Atmosphere. http://ftp.aer.com/pub/anon_collaborations/sba/
  27. SBO (2009) WEB site of the IERS Special Bureau for the Oceans. http://euler.jpl.nasa.gov/sbo/
  28. Sidorenkov (2002) Fizika nestabil’nostey vrazheniya Zemli (Physics of the instabilities of the Earth’s rotation). Fizmatlit, Moscow, 384 p, ISBN 5-9221-0244-3 (in Russian)Google Scholar
  29. Sidorenkov N (2003) Influence of the atmospheric tides on the Earth rotation. Celest Mech Dyn Astron 87(1–2): 27–38CrossRefGoogle Scholar
  30. Sidorenkov N (2008) Lunno-solnechnie prilivi i atmosferenie protsessi (Luni-solar tides and atmospheric processes, in Russian). Priroda 2: 23–31Google Scholar
  31. Vondrak J (1969) A contribution to the problem of smoothing observational data. Bull Astron Inst Czech 20: 349Google Scholar
  32. Vondrak J (1977) Problem of smoothing observational data II. Bull Astron Inst Czech 28: 84–89Google Scholar
  33. WilsonCR(1985) Discrete polar motion equations.Geophys JRAstron Soc 80(2):551–554Google Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  1. 1.Paris Observatory, SYRTEParisFrance

Personalised recommendations