Gravity Recovery and Climate Experiment (GRACE) mission data is widely used in various fields of science. GRACE explored changes of the gravity field regularly from April 2002 to June 2017. In the following research, we examine variance of signal contained in two different formats of GRACE data: standard spherical harmonics and mass concentration blocks (so-called “mascons”) solutions, both provided in the most recent releases. For spherical harmonics-based solution, we use monthly gravity field solutions provided up to degree and order (d/o) 96 by three different computing centers, i.e. the NASA’s Jet Propulsion Laboratory (JPL), the German Research Center for Geosciences (GFZ) and the Center for Space Research (CSR). For the mass concentration blocks, we use values of total water storage provided by the CSR, JPL and the Goddard Space Flight Center (GSFC) computing centers, which we convert to spherical harmonic coefficients up to d/o 96. We show that using the anisotropic DDK3 filter to smooth the north-south stripes present in total wate storage obtained from standard spherical harmonics solution leaves more information than common isotropic Gaussian filter. In the case of mascons, GSFC solution contains much more information than the CSR and JPL releases, relevant for corresponding d/o. Differences in variance of signal arise from different background models as well as various shape and size of mascons used during processing of GRACE observations.
Time variations of the gravity field derived from time series of geopotential model developed from GRACE data can be interpreted in terms of geoid heights, and mass time variations with unprecedented temporal resolution. Following the results of authors previous research presented at 2nd General Assembly of the IGFS, 20-22 September 2010, Fairbanks, Alaska, the series of monthly solutions of geopotential models developed from GRACE data in JPL, filtered with the use of DKK1 filter, and GLDAS hydrological model were used in the analyses. Variations of hydrology as well as variations of geoid heights for the period August 2002 – June 2010 at the continental part of Europe and selected 14 subareas were estimated with spatial resolution of 0.5° x 0.5° . Variations in mass distribution obtained from geopotential models were compared with the respective results obtained from hydrological data. Models of geoid height changes (parameters of trend and seasonal variations) were determined for the area of Europe and for 14 subareas. To verify models of geoid height changes, over the period July 2010 - October 2010 values of geoid height changes calculated using GRACE data were compared with values based on the models developed.
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