A Global Mean Ocean Circulation Estimation Using Goce Gravity Models – the Dtu12mdt Mean Dynamic Topography Model

The Gravity and Ocean Circulation Experiment GOCE satellite mission measure the Earth gravity field with unprecedented accuracy leading to substantial improvements in the modelling of the ocean circulation and transport. In this study of the performance of GOCE, a newer gravity model have been combined with the DTU10MSS mean sea surface model to construct a global mean dynamic topography model named DTU10MDT. The results of preliminary analyses using preliminary GOCE gravity models clearly demonstrated the potential of GOCE mission. Both the resolution and the estimation of the surface currents have been improved significantly compared to results obtained using pre-GOCE gravity field models. The results of this study show that geostrophic surface currents associated with the mean circulation have been further improved and that currents having speeds down to 5 cm/s have been recovered.