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Vertical motions across the ocean are central to processes, like CO2 fixation, heat removal or pollutant transport, which are essential to the Earth's climate. This work explores 3D conveyor routes associated with the Atlantic Meridional Overturning Circulation (AMOC). Our findings show the geometry of mixing structures in the upper and deep ocean layers by means of Lagrangian Coherent Structures. This tool identifies among others, zones linked to vertical transport and characterizes vertical transport time scales. We focus the study in two regions. The first one is the Flemish Cap region, a zone of interaction between the major AMOC components, where our analysis identifies a domain of deep waters that ascend very rapidly to the ocean surface. The second one is the Irminger Sea, where our analysis confirms the existence of a downwelling zone, and reveals a previously unreported upwelling connection between very deep waters and the ocean surface.

The Atlantic Meridional Overturning Circulation (AMOC) is a complex system of shallow and deep currents in the Atlantic Ocean which plays a crucial role in the regulation of the Earth's climate. Lagrangian Coherent Structures (LCS) are geometric objects existing in the extended phase space of dynamical systems which organise the flow around them. Currently there exist several methods for the detection of LCS. We describe and discuss the use of Lagrangian descriptors as a tool for detecting LCS and apply it in the case of the AMOC to study and identify relevant transport pathways. We successfully identify the main components of the AMOC and their interactions and observe new convective regions off the coast of the United States and the Grand Banks of Newfoundland.