Abstract
The gravity field of the Earth can be divided into a dominant quasi-static part and several relatively small but significant temporal constituents. Important examples of temporal sources are ocean tides, atmospheric pressure variations, and geophysical signals like those of continental hydrology and ocean bottom pressure variations predicted by the ECCO ocean model. Space-borne gravimetry, such as by the GRACE system, aims at observing including those induced by continental hydrology. A case study, based on a simulated gravity field retrieval for a 1-year GRACE-type mission, has been conducted to analyze the separability of continental hydrology from other temporal gravity sources.
It has been investigated how typical differences between recent ocean tide models and between global atmospheric pressure variation maps affect the observations (low-low satellite-to-satellite range-rate tracking (SST) and orbital positions from GPS high-low SST) and retrieved gravity field spherical harmonic expansions. In addition, the aliasing of signals predicted by the ECCO model and the effect of low-low SST observation noise and uncertainties in the recovered orbital positions has been analyzed.
It is concluded that large scale features of continental hydrology can be observed by a GRACE-type mission, provided that the low-low SST observations have a precision at the level of 1 µm/s at 1 Hz, and when great care is taken with the gravity field recovery approach.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsPreview
Unable to display preview. Download preview PDF.
References
Cazenave, A., and R.S. Nerem (2002), Redistributing Earth’s Mass, Science, 297, 783–784, August 2002.
Cox, C.M., and B.F. Chao (2002), Detection of Large-Scale Mass Redistribution in the Terrestrial System Since 1998, Science, 297, 831–833, August 2002.
ECCO homepage, http://www.ecco-group.org/, last accessed: July 2004
ESA (1999), Gravity Field and Steady-State Ocean Circulation Mission, Reports for Mission Selection, The Four Candidate Earth Explorer Core Missions, SP-1233(1), European Space Agency, July 1999.
Fan, Y., and H. van den Dool (2004), Climate Prediction Center global monthly soil moisture data set at 0.5° resolution for 1948 to present, J. Geophys. Res., 109(D10), 8 pp., May 2004.
GRACE CSR homepage, http://www.csr.utexas.edu/grace/gravity, last accessed: July 2004
Han, S.-C., C. Jekeli, and C.K. Shum (2004), Time-variable aliasing effects of ocean tides, atmosphere, and continental water mass on monthly mean GRACE gravity field, J. Geophys. Res., 109(B4), doi: 10.1029/2003JB002501.
Lefèvre, F., F.H. Lyard, C. LeProvost, and E.J.O. Schrama (2002), FES99: A Global Tide Finite Element Solution Assimilating Tide Gauge and Altimetric Information, Journal of Atmospheric and Oceanic Technology, 19(9), 1345–1356.
Ray, R D (1999), A global ocean tide model from Topex/Poseidon altimetry: GOT99.2, NASA Tech. Memo. 209478, 58 pp., Goddard Space Flight Center.
Reigber, Ch., P. Schwintzer, and H. Lühr (1999), The CHAMP geopotential mission, in Bollettino di Geofisica Teorica ed Applicata, Vol. 40, No. 3–4, Sep.–Dec. 1999, Proceedings of the 2nd Joint Meeting of the International Gravity and the International Geoid Commission, Trieste 7–12 Sept. 1998, ISSN 0006-6729, edited by I. Marson and H. Sünkel, pp. 285–289.
hspace*-3mm Rowlands, D., J.A. Marshall, J. McCarthy, D. Moore, D. Pavlis, S. Rowton, S. Luthcke, and L. Tsaoussi (1995), GEODYN II system description, Vols. 1–5, Contractor report, Hughes STX Corp., Greenbelt, MD.
Schrama, E.J.O. (2003), Error characteristics estimated from CHAMP, GRACE and GOCE derived geoids and from satellite altimetry derived mean dynamic topography, Space Science Reviews, 108, 179–193.
Tapley, B.D., and C. Reigber (1999), GRACE: a satellite-to-satellite tracking geopotential mapping mission, in Bollettino di Geofisica Teorica ed Applicata, Vol. 40, No. 3–4, Sep.–Dec. 1999, Proceedings of the 2nd Joint Meeting of the International Gravity and the International Geoid Commission, Trieste 7–12 Sept. 1998, ISSN 0006-6729, edited by I. Marson and H. Sünkel, p. 291.
Tapley, B.D., S. Bettadpur, J.C. Ries, P.F. Thompson, and M.M. Watkins (2004), GRACE Measurements of Mass Variability in the Earth System, Science, 305, 1503–505.
Velicogna, I., J. Wahr, and H. Van den Dool (2001), Can surface pressure be used to remove atmospheric contributions from GRACE data with sufficient accuracy to recover hydrological signals?, J. Geophys. Res., 106(B8), doi: 10.1029/2001JB900228.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2005 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Visser, P., Schrama, E. (2005). Space-borne gravimetry: determination of the time variable gravity field. In: Jekeli, C., Bastos, L., Fernandes, J. (eds) Gravity, Geoid and Space Missions. International Association of Geodesy Symposia, vol 129. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-26932-0_2
Download citation
DOI: https://doi.org/10.1007/3-540-26932-0_2
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-26930-4
Online ISBN: 978-3-540-26932-8
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)