Chairs: H. Sünkel, P. Visser Session 2: The new GOCE science products, gravity field models and gravity gradient data Chairs: H. Sünkel, P. Visser

Questions, discussion items Global models Representation: spherical harmonics, Mascons, Wavelets, hybrid, … Extent of GOCE contribution to Mean Earth Gravity Models Contribution of GOCE precise science orbits Gravity gradient grids Spatial and temporal(!) resolution Supporting data (long wavelengths) Reference frames (GRF, NEU) Global models – representation forms: Do the global models optimally capture the information of the GOCE gravity gradient observations? For example, for certain geographical areas higher geoid errors, that is above 2 cm and even significantly above that, might still be acceptable for certain applications. Take for example Western boundary current areas. Spherical harmonics are not efficient in capturing high-spatial resolution features. Hybrid models might be efficient, where a relatively low-degree spherical harmonic expansion (still up to degree and order 250?) is estimated together with higher spatial resolution basis functions (down to 30-50 km?) for relevant geographical areas. Gravity gradient grids: Deriving grids of observed GOCE gravity gradients at for example – mean – satellite altitude have revealed interesting time variable signals. Possibly more can be done …

Questions, discussion items Applications Oceanography, Solid-Earth, Glaciology Quality information Covariance matrices Accuracy assessment gravity gradients Applications: Are we overlooking interesting possibilities for further utilizing the GOCE data? Quality information: Is the quality information that accompanies GOCE data products actually being used? If not, what is the reason and would such information in other form be valuable? If yes, are enhancements possible?