DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Lagrangian Transport Signatures in Models and Observations

We are interested in describing and understanding the processes that influence individual particle trajectories and their collective behavior, in terms of such quantities as dispersion and cohesion, and the statistics thereof. In order to achieve this goal we rely heavily on state-of-the-art, data assimilating ocean models. In spite of extensive Eulerian validation, the reliability of the models ’ Lagrangian forecasts remains uncertain. Thus, we strive to rectify this situation by analyzing the correspondence of modeled features with available observations. The insights gained from such a study should inform both interpretation of model results and model development. OBJECTIVES The main objectives of this effort are to identify the signatures of ocean transport processes in both observations and models and to assess the uncertainty in these model predictions. Scientifically, our interest is in the ocean dynamics responsible for mesoscale features and their interaction with flows at other scales. Our primary concern is the evolution of eddies and the development of fronts near strong jets, in both models and observations. In FY10, our focus was predominantly on developing methods for defining, locating, and tracking eddy centers and boundaries, with an initial foray into the analysis of the water mass exchange between eddies and their environment