EIGEN-6S4 A time-variable satellite-only gravity field model to d/o 300 based on LAGEOS, GRACE and GOCE data from the collaboration of GFZ Potsdam and GRGS Toulouse

EIGEN-6S4 is satelite-only global gravity field model from the combination of LAGEOS, GRACE and GOCE data. All spherical harmonic coefficients up to degree/order 80 are time variable. Their time variable parameters consist of drifts as well as annual and semi-annual variations per year. The time series of the time variable spherical harmonic coefficients are based on the GRACE-LAGEOS monthly gravity fields RL03-v1 (2003.0-2013.0) from GRGS/Toulouse (Bruinsma et al. 2009).The herein included GRACE data were combined with all GOCE data which have been processed via the direct numerical approach (Pail et al. 2011). The polar gap instabilty has been overcome using the Sperical Cap Regularization (Metzler and Pail 2005). That means this model is a combination of LAGEOS/GRACE with GO_CONS_GCF_2_DIR_R5 (Bruinsma et al. 2013). We recommmend to use the updated version of this dataset (Förste et al. 2016, http://doi.org/10.5880/icgem.2016.008). that contains an improved modelling of the time variable part, in particular for C20.