Skip to main content
Article thumbnail
Location of Repository

Effects of self-attraction and loading on annual variations of ocean bottom pressure

By Nadya T. Vinogradova, Rui M. Ponte, Mark E. Tamisiea, James L. Davis and Emma M. Hill


The impact of self-attraction and loading (SAL) on ocean bottom pressure xi, an effect not previously considered, is analyzed in terms of the mean annual cycle based on decade long estimates of changes in land hydrology, atmospheric pressure, and oceanic circulation. The SAL-related changes in xi occur as a result of deformation of the crust due to loading and self-gravitation of the variable fluid loads. In the absence of SAL, net freshwater input and changes in mean atmospheric pressure over the ocean give rise to a spatially constant xi annual cycle with an amplitude similar to 1-2 cm in equivalent water thickness. Consideration of SAL physics introduces spatial variations that can be significant, particularly around continental boundaries, where the amplitude of deviations can exceed 1 cm. For the spatial variability induced by SAL effects, changes in both land hydrology and atmospheric pressure are important. Effects related to the changing ocean circulation are relatively weaker, apart from a few shallow coastal regions. Comparisons with a few in situ, deep ocean observations indicate that for the most accurate xi estimates, one needs to consider spatially varying SAL-related signals, along with the effects of mean atmospheric pressure and net freshwater input into the oceans. Nevertheless, the most complete estimates, including also effects of ocean circulation, are able to account for only similar to 1/3 of the observed annual variances. Sources of the remaining contribution remain unclea

Topics: Marine Sciences
Publisher: American Geophysical Union
Year: 2010
DOI identifier: 10.1029/2009jc005783
OAI identifier:

Suggested articles


  1. (2007). A comparison of model and GRACE estimates of the large‐scale seasonal cycle in ocean bottom pressure, doi
  2. (1999). A preliminary model study of the large‐scale seasonal cycle in bottom pressure over the global ocean, doi
  3. (1996). Bottom pressure correlations in the South Atlantic,
  4. (2007). Dynamic and regression modeling of ocean variability in the tide‐gauge record at seasonal and longer periods,
  5. (2005). Effect of gravitational consistency and mass conservation on seasonal surface mass loading models,
  6. (2008). Estimating weights for the use of time‐dependent gravity recovery and climate experiment data in constraining ocean models, doi
  7. Hughes (2004), Parameterization of ocean self‐ attraction and loading in numerical models of the ocean circulation, doi
  8. (2001). Modeling the high‐frequency barotropic response of the ocean to atmospheric disturbances: Sensitivies to forcing, topography, and friction,
  9. (1998). Nature of global large‐ scale sea level variability in relation to atmospheric forcing: A modeling study,
  10. (1998). Ocean self‐attraction and loading in numerical tidal models, doi
  11. (2005). On post‐glacial sea level—II. Numerical formulation and comparative results on spherically symmetric models, doi
  12. (1991). On postglacial geoid subsidence over the equatorial oceans, doi
  13. (2007). Practical global oceanic state estimation, doi
  14. (2004). Preliminary observations of global ocean mass variations with GRACE,
  15. (2005). Seasonal global mean sea level change from satellite altimeter, GRACE, and geophysical models,
  16. (1977). The effects of loading and self‐attraction on global ocean tides: The model and the results of a numerical experiment,
  17. (2009). The global general circulation of the oceans estimated by the ECCO‐consortium, doi
  18. (2008). The mean seasonal cycle in sea level estimated from a data‐constrained general circulation model, doi
  19. (1996). The NCEP/NCAR 40‐year reanalysis project,
  20. (1973). The theory of the seasonal variability in the ocean, Deep Sea Res.
  21. (2005). Time variation in hydrology and gravity,
  22. Vinogradova (2010), Impact of self‐attraction and loading on the annual cycle in sea level, doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.