Journal cover Journal topic
Advances in Geosciences An open-access journal for refereed proceedings and special publications
Journal topic

Journal metrics

Journal metrics

  • CiteScore value: 1.68 CiteScore
    1.68
  • SNIP value: 0.913 SNIP 0.913
  • SJR value: 0.651 SJR 0.651
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 34 Scimago H
    index 34
  • h5-index value: 13 h5-index 13
Volume 1
Adv. Geosci., 1, 65–71, 2003
https://doi.org/10.5194/adgeo-1-65-2003
© Author(s) 2003. This work is licensed under
the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.
Adv. Geosci., 1, 65–71, 2003
https://doi.org/10.5194/adgeo-1-65-2003
© Author(s) 2003. This work is licensed under
the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 License.

  17 Jun 2003

17 Jun 2003

The potential of ground gravity measurements to validate GRACE data

D. Crossley1, J. Hinderer2, M. Llubes3, and N. Florsch4 D. Crossley et al.
  • 1Earth and Atmospheric Sciences, Saint Louis University, 3507 Laclede Ave., St. Louis, MO 63103, USA
  • 2Institut de Physique du Globe / EOST, 5 Rue Descartes, Strasbourg 67084, France
  • 3LEGOS/CMES/CNRS Toulouse, France
  • 4Department de Geophysique Appliquee, UMR 7619 Sisyphe, Paris, France

Abstract. New satellite missions are returning high precision, time-varying, satellite measurements of the Earth’s gravity field. The GRACE mission is now in its calibration/- validation phase and first results of the gravity field solutions are imminent. We consider here the possibility of external validation using data from the superconducting gravimeters in the European sub-array of the Global Geodynamics Project (GGP) as ‘ground truth’ for comparison with GRACE. This is a pilot study in which we use 14 months of 1-hour data from the beginning of GGP (1 July 1997) to 30 August 1998, when the Potsdam instrument was relocated to South Africa. There are 7 stations clustered in west central Europe, and one station, Metsahovi in Finland. We remove local tides, polar motion, local and global air pressure, and instrument drift and then decimate to 6-hour samples. We see large variations in the time series of 5–10µgal between even some neighboring stations, but there are also common features that correlate well over the 427-day period. The 8 stations are used to interpolate a minimum curvature (gridded) surface that extends over the geographical region. This surface shows time and spatial coherency at the level of 2– 4µgal over the first half of the data and 1–2µgal over the latter half. The mean value of the surface clearly shows a rise in European gravity of about 3µgal over the first 150 days and a fairly constant value for the rest of the data. The accuracy of this mean is estimated at 1µgal, which compares favorably with GRACE predictions for wavelengths of 500 km or less. Preliminary studies of hydrology loading over Western Europe shows the difficulty of correlating the local hydrology, which can be highly variable, with large-scale gravity variations.

Key words. GRACE, satellite gravity, superconducting gravimeter, GGP, ground truth

Download
Citation