The gravitational sinking of organic particles is a vital component of the biological carbon pump. This sinking process is strongly modulated by the spatiotemporally varying eddy field, complicating the interpretation of particle flux measured by deep‐moored sediment traps. By backtracking particles to 200 m depth based on the outputs of a realistic eddy‐resolving simulation, we characterize the origins of particles collected at a long‐term observatory site in the Northeast Atlantic and focus on the impact of mesoscale dynamics on particle transport. Our results show that mesoscale dynamics between 200 and 1,000 m control the statistical funnel. Over the long term, the horizontal sampling scales of traps are estimated as hundreds of kilometers, with containment radius ranging from 90 to 490 km, depending on sinking velocities. Particle travel time suggests that overall vertical flow acts to facilitate the export, with estimated deviations up to 1 ± 2 days for particles sinking at 50 m d−1 to 1,000 m. Statistical analyses of horizontal displacements reveal that mesoscale eddies at the site confine particle sources in a more local area. On average, particles in anticyclonic eddies sink faster to depth than expected from purely gravitational sinking, contrary to their counterparts in cyclonic eddies. The results highlight the critical role of mesoscale dynamics in determining particle transport in a typical open ocean region with moderate eddy kinetic energy. This study provides implications for the sampling design of particle flux measurements during cruises and the interpretation of deep‐ocean mooring observations.

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International audienceWhen a source-sink dipole forces a fluid on a -plane limited by a western boundary, the linear steady solution can be obtained analytically and consists of zonally elongated gyres that extend west of the forcing and close as western boundary currents. The nondimensional parameter (with the zonal velocity of the flow and the distance between the source and sink) is used to characterize the nonlinearity of the flow. When reaches 0.1, the numerical shallow-water solution shows that the configuration with the source to the north of the sink becomes unstable, while the reverse configuration remains steady. Indeed, that reverse configuration remains steady for much larger values of the nonlinearity parameter , and begins to share some of the characteristics of a pure inertial circulation. The asymmetry of the stability properties of the two configurations, also found in the laboratory experiments of Colin de Verdière [Quasigeostrophic flows and turbulence in a rotating homogeneous fluid, 1977], is rationalized herein through the stability properties of the zonal central jet that flows between the source and sink. We consider, in turn, (i) the Kuo’s [J. Meteor. 1949, 6, 105–122] zero potential vorticity gradient necessary criteria (valid for an infinite zonal jet), (ii) enstrophy budgets and (iii) linear stability analysis of the mean flow. All three methods point out to the enhanced instability of the westward jet. We show that the transition regime has the characteristics of a super critical Hopf bifurcation