Mesoscale Variabilities in Sea Surface Current Fields Derived through Multi-sensor Tracking of Sea Surface Films

In recent studies [1], we have already shown that it is possible to derive mesoscale sea surface current fields by tracking signatures of marine surface films in multisensor satellite data. Although the derived sea surface current fields corresponded well with those provided by numerical models, the former mainly showed largescale current properties. This is insofar remarkable, as the traced signatures clearly follow local dynamical features such as eddies or dipoles. In this paper, we present a new approach, which allows to extract, and even overemphasize, the affine local current component for the derived current fields [2]. Depending on the spatial resolution of the derived current fields this method allows a deeper insight into the turbulent nature of those fields. As a result, the imaged signatures can be seen as local variabilities of sea surface currents of larger scales. Moreover, these local variabilities seem to be mainly independent of the ‘global’ currents.