Diagnosing the Transition Zones and Regional Dependencies of the Inverse Energy Cascade in the Eastern South Atlantic using Satellite Data

Energy cannot be created nor destroyed; it can merely be transferred to different scales. Scott, Robert B., and Faming Wang (2005) showed that in the South Pacific, energy is transferred from mesoscale eddies to large ocean currents (inverse energy cascade). The regional dependencies of the inverse cascade are still not well understood and thus limit the correct parameterisation of energy transfers in climate models. The eastern South Atlantic (0-10°E, 30-35°S) offers a large dataset (satellite as well as drifter data) containing several high energetic processes, such as strong mesoscale eddies. The presence of such energetic mesoscale processes makes the question if the energy is transferred to larger scales, an especially interesting one. To investigate the spectral transitions of the inverse energy cascade, we calculate the energy flux similarly to Scott, Robert B., and Faming Wang (2005) using Sea Surface Height (SSH) satellite data and analyse the results for regional changes. Secondly, we use the same SSH dataset to calculate second- and third-order velocity structure functions (S2,S3). As S2,S3 are usually calculated from surface drifter datasets, this provides a new Eulerian insight into transition zones, making structure functions more widely applicable.