Combination of temporal gravity variations resulting from superconducting gravimeter (SG) recordings, GRACE satellite observations and global hydrology models
- Author(s)
- J Neumeyer, F Barthelmes, O Dierks, F Flechtner, M Harnisch, G Harnisch, Jacques Hinderer, Y Imanishi, C Kroner, Bruno Meurers, Slavica Petrovic, Ch Reigber, R Schmidt, P Schwintzer, H -P Sun, H Virtanen
- Abstract
Gravity recovery and climate experiment (GRACE)-derived temporal gravity variations can be resolved within the œgal (10-8 m/s2) range, if we restrict the spatial resolution to a half-wavelength of about 1,500 km and the temporal resolution to 1 month. For independent validations, a comparison with ground gravity measurements is of fundamental interest. For this purpose, data from selected superconducting gravimeter (SG) stations forming the Global Geodynamics Project (GGP) network are used. For comparison, GRACE and SG data sets are reduced for the same known gravity effects due to Earth and ocean tides, pole tide and atmosphere. In contrast to GRACE, the SG also measures gravity changes due to load-induced height variations, whereas the satellite-derived models do not contain this effect. For a solid spherical harmonic decomposition of the gravity field, this load effect can be modelled using degree-dependent load Love numbers, and this effect is added to the satellite-derived models. After reduction of the known gravity effects from both data sets, the remaining part can mainly be assumed to represent mass changes in terrestrial water storage. Therefore, gravity variations derived from global hydrological models are applied to verify the SG and GRACE results. Conversely, the hydrology models can be checked by gravity variations determined from GRACE and SG observations. Such a comparison shows quite a good agreement between gravity variation derived from SG, GRACE and hydrology models, which lie within their estimated error limits for most of the studied SG locations. It is shown that the SG gravity variations (point measurements) are representative for a large area within the œgal accuracy, if local gravity effects are removed. The individual discrepancies between SG, GRACE and hydrology models may give hints for further investigations of each data series. Œ Springer-Verlag 2006.
- Organisation(s)
- Department of Meteorology and Geophysics
- External organisation(s)
- Helmholtz-Zentrum Potsdam Deutsches GeoForschungsZentrum, Bundesamt für Kartographie und Geodäsie, Université de Strasbourg, University of Tokyo, Friedrich-Schiller-Universität Jena, Chinese Academy of Sciences (CAS), Finnish Geodetic Institute
- Journal
- Journal of Geodesy
- Volume
- 79
- Pages
- 573-585
- No. of pages
- 13
- ISSN
- 0949-7714
- Publication date
- 2006
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105102 General geophysics
- Sustainable Development Goals
- SDG 13 - Climate Action
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/2c137d7f-6ea5-485b-aa94-431d0a3da75e