Massentransporte und Massenverteilungen im System Erde  
    TASMAGOGTASMAGOG  
 

 

TASMAGOG

“Temporal And Spatial Multiscale Assessment of mass transport by combination of Gravity

Observations from GRACE and terrestrial stations”

Project Partners are:

  • Helmholtz-Zentrum Potsdam DeutschesGeoForschungsZentrum (GFZ), Section 1.3 and 5.4
  • Federal Agency for Cartography and Geodesy (BKG), Frankfurt/Main
  • Friedrich-Schiller University Jena (FSU), Institute of Geosciences
Figure 1: Superconducting Gravimeter
Superconducting Gravimeter

Concept:

In this project continuous terrestrial gravity observations are compared with the time-dependent satellite gravity field models derived in the GRACE mission. The terrestrial gravity data come from European stations in the network of superconducting gravimeters (Fig.1) of the Global Geodynamics Project (GGP).

 

Their observations are combined with repeated absolute gravity measurements to remove instrumental drift effects. Temporal gravity variations are reduced by models for Earth and Ocean Tides, polar motion and atmosphere. The remaining variations are attributed to water-storage changes. Such changes have global, regional and local constituents. For comparison with GRACE derived gravity variations local influences upon the terrestrial stations must be investigated and possibly removed.

Goals:

Figure 2: European stations of the GGP network presently involved in the project
Map of selected European GGP stations

Assessment of satellite-derived gravity field variations by SG/AG observations and GPS

  • Combination of SG time series and AG measurements to check calibration parameters and ensure long term stability of the terrestrial times series.
  • Separation of gravity changes due to mass changes from those induced by vertical deformations by means of precise GPS time series.
  • Investigation and separation of site specific local hydrological effects by establishing local hydrological models.
  • Development of a procedure to compare satellite derived gravity variations with terrestrial observations consistently. The gap in spatial and temporal resolution between gravity field variations obtained from the GRACE mission and the combined terrestrial time series will be bridged by estimating principal components of both signals in time and space.
  • Contributing to improve the processing of the GRACE data by comparing different filtering techniques with respect to optimal conservation of amplitudes.

Quantification of mass variations in continental hydrology

  • Determination of gravity effects at SG sites from existing global hydrological models and hydrological models for Europe, comparison with the effects contained in GRACE and terrestrial observations, sensitivity analysis regarding the relation between magnitude of hydrological variation from defined regional units, distance to SG site and magnitude of gravity effect.
  • Discrimination and comparison of local and global water storage variations for SG sites based on hydrological observations and models.
  • Development of a calibration scheme for the WaterGAP Global Hydrology Model (WGHM) to use the combined gravity data set as a constraint for model simulations.

List of Publications

 

Abe, M., Kroner, C., Neumeyer, J., Chen, X.D., 2010. Assessment of atmospheric reductions for terrestrial gravity observations. Bull. d‟Inf. Marées Terr., 146, 11817–11838, in press.

 

Creutzfeldt, B., Güntner, A., Klügel, T., Wziontek, H., 2008. Simulating the influence of water storage changes on the superconducting gravimeter of the Geodetic Observatory Wettzell, Germany. Geophysics, 73, 6, WA95, doi: 10.1190/1.2992508.


Creutzfeldt, B.; Güntner, A.; Thoss, H.; Merz, B.; Wziontek, H., 2010a. Measuring the effect of local water storage changes on in-situ gravity observations: Case study of the Geodetic Observatory Wettzell, Germany. Water Resources Research , 46, W08531, DOI: 10.1029/2009WR008359.


Creutzfeldt, B., A. Güntner, H. Wziontek, B. Merz, 2010b. Reducing local hydrology from high precision gravity measurements: a lysimeter-based approach. Geophysical Journal International. doi: 10.1111/j.1365-246X.2010.04742.x


Güntner , A., 2008. Improvement of global hydrological models using GRACE data. Surveys in Geophysics,
29(4), 375-397.

 

Klügel, T. and Wziontek, H. Correcting Gravimeters and Tiltmeters for Atmospheric Attraction using Operational Weather Models, J. Geodynamics, 48, 204-210, doi:10.1016/j.jog.2009.09.010


Kroner, C., Werth, S., Pflug, H., Güntner, A., Creutzfeldt, B., Thomas, M., Dobslaw, H., Fourie, P., Charles, Ph., 2010. Signals of mass redistribution at the South African gravimeter site SAGOS. Proc. IAG General Ass., Buenos Aires, Sept. 2009, accepted.

 

Kroner, C., Thomas, M., Dobslaw, H., Abe, M., Weise, A.., 2009. Seasonal effects of non-tidal oceanic mass shifts in observations with superconducting gravimeters. J. Geodynamics, 48, 354-359. doi: 10.1016/ .jog.2009.09.009.

 

Neumeyer, J., Barthelmes, F., Kroner, C., Petrovic, S., Schmidt, R., Virtanen, H. , Wilmes, H., 2008. Analysis of gravity field variations derived from superconducting gravimeter recordings, GRACE satellite and hydrological models at selected European sites. Earth, Planets and Space, 60(5), 505-518

 

Weise, A., C. Kroner, M. Abe, J. Ihde, G. Jentzsch, M. Naujoks, H. Wilmes, H. Wziontek, 2009. Gravity field variations from superconducting gravimeters for GRACE validation. J. Geodynamics, 48, 325-330, doi:10.1016/j.jog.2009.09.034

 

Weise, A., C. Kroner, M. Abe, B.Creutzfeldt, C.Foerste, A.Güntner, J. Ihde, T.Jahr, G. Jentzsch, H. Wilmes, H. Wziontek, S.Petrovic. Tackling mass redistribution phenomena by time-dependent GRACE- and terrestrial
gravity observations,submitted. Journal of Geodynamics (Special Issue).

 

Wziontek, H., Falk, R., Wilmes, H., Wolf, P., 2009. Precise gravity time series and instrumental properties from combination of superconducting and absolute gravity measurements. In M. Sideris (ed.), Observing our Changing Earth, International Association of Geodesy Symposia 133, Springer, Berlin, 301-306

 

Wziontek, H., H. Wilmes, P. Wolf,S. Werth and A. Güntner, 2009. Time series of superconducting gravimeters and water storage variations from the global hydrology model WGHM. J. Geodynamics, 48, 166-171, doi:10.1016/j.jog.2009.09.036