Enhanced Mean Dynamic Topography And Ocean Circulation Estimation Using Goce Preliminary Mode

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, the new preliminary gravity models have been combined with the recent DNSC08MSS mean sea surface model to construct a global GOCE satellite-only mean dynamic topography model. At a first glance, the GOCE MDT display the well known features related to the major ocean current systems. A closer look, however, reveals that the improved gravity provided by the GOCE mission has enhanced the resolution and sharpened the boundary of those features. A computation of MDT slopes clearly displays the improvements in the description of the current systems. In the North Atlantic Ocean, the Gulf Stream is very well defined and the Labrador and the Greenland currents are clearly displayed. Furthermore, different branches of the North Atlantic Current are seen. In the North Pacific Ocean, the Kuroshio and its extension are well recovered, also with its branches. In the Southern hemisphere, both the Aghulas and the South Atlantic current systems are very clearly displayed. In the Antarctic Circumpolar Current system different flow paths are revealed. The results of this preliminary analysis using preliminary GOCE gravity models clearly demonstrate the potential of GOCE mission. Already at this stage the resolution and the estimation of the surface currents have been increased by at least a factor of two compared to similar pre-GOCE satellite-only studies. Future GOCE models are expected