Coherent Vortices in the Ocean interior of the Atlantic

Previous studies have extensively described the coherent vortices at the ocean surface and shallow sub-surface at global and regional scales (from satellites, in-situ measurements, and numerical models). Few studies have investigated the dynamics of the deep coherent vortices (DCVs) below the mixed layer depth. This study focuses on DCVs in the Atlantic Ocean using a high-resolution numerical model. Since the properties of the water asses move along isopycnals, the detection and tracking of DCVs are performed along three isopycnal surfaces: 27.60 kg/m3, 27.80 kg/m3, and 27.86 kg/m3 with depths of 250-1700 m, 1200-2800 m, and 1900-3800 m, respectively. The quantification of the physical characteristics of the DCVs (population, radius, Rossby number, polarity between cyclones and anticyclones, and propagation in space and time) in different parts of the Atlantic Ocean (Mediterranean Water vortices, meddies and Mid-Atlantic Ridge, MAR). The dynamics involved in the generation and destruction of the DCVs throughout their life cycle are analyzed.There is an asymmetry between cyclonic DCVs and anticyclonic DCVs, as they propagate poleward and equatorward, respectively, due to the beta-effect. Cyclonic DCVs tend to be smaller and shorter lived than anticyclonic DCVs, so anticyclones dominate in terms of energetic, large, long-lived, and long-distance DCVs. The results also show that anticyclonic meddies, as well as other DCVs, can cross MAR. The region of the ocean west of the MAR is also characterised by a large number of shielded vortices and the formation of a group of transient shielded multiplets. The DCVs contribute to the transport of characteristic properties of different water masses from their source origin to the distance offshore.This sheds new light on the understanding of the formation, life cycle, physical and dynamical properties of the ocean interior in the Atlantic Ocean for the long-lived DCVs.