Extracting statistically significant eddy signals from large Lagrangian datasets using wavelet ridge analysis, with application to the Gulf of Mexico

Abstract. A method for objectively extracting the displacement signals associated with coherent eddies from Lagrangian trajectories is presented, refined, and applied to a large dataset of 3770 surface drifters Gulf Mexico. The method, wavelet ridge analysis, general analysis modulated oscillations, here modified be more suitable eddy-detection problem. means formally assessing statistical significance introduced, addressing issue false positives arising by chance an unstructured turbulent background opening door confident application very datasets. Significance measured through frequency-dependent comparison stochastic having spectral properties that match original, but lacking organized oscillations due or waves. Mexico reveals major asymmetries between cyclones anticyclones, anticyclones dominating at radii larger than about 50 km, unexpectedly rich population highly nonlinear smaller radii. Both eddy are made freely available community noncommercial use in future research.