Relative Dispersion in the Antarctic Circumpolar Current

The Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) was designed to provide the first high resolution data set to better understand the mixing processes at work in the Antarctic Circumpolar Current (ACC). Quasi-isopycnal RAFOS floats were deployed as part of DIMES to capture lateral (along-isopycnal) dispersion caused by the rich eddy field of the ACC. The floats were deployed in pairs and triplets, to yield information about separation rates and, in turn, about  sub-mesoscale stirring in the ACC. We analyze the relative (two particle) dispersion of the floats and compare the results to those obtained with synthetic particle trajectories from a high resolution run of MITgcm. Preliminary results show the relative dispersion is isotropic to about 80km separations and non-local, with separations growing exponentially in time. The results imply steep wavenumber spectra. The model results are used to further explore depth variations of the time and length scales of the dispersion in the DIMES region.