Abstract
Mesoscale eddies transport tracers along isopycnals through two mechanisms: diffusive "stirring" from turbulent motion around the eddy, and coherent advective "drift" from water trapped within the eddy core. Their relative importance for tracer budgets remains unresolved. Using Argo profiles co-located within satellite-tracked eddies, we build a global dataset of along-isopycnal eddy diffusivities that, by accounting for advection by eddy translation, are up to an order of magnitude smaller than previous estimates.