Oceanic Mesoscale Cyclones Cluster Surface Lagrangian Material

Clément Vic (1) , Solenne Hascoët (1) , Jonathan Gula (1, 2, 3) , Christophe Maes (1) , Thierry Huck (1)

1 LOPS - Laboratoire d'Océanographie Physique et Spatiale
2 IUF - Institut Universitaire de France
3 ODYSSEY - Océan Dynamique Observations Analyse

An asymmetry in the clustering of oceanic surface material has been observed at the submesoscales. Energetic and ephemeral submesoscale cyclonic fronts are associated with convergence zones, hence cluster surface material. Their anticyclonic counterparts do not feature such an effect. Yet, at the mesoscale, literature has been contradictory about such an asymmetry. Here, we combine surface drifter trajectories with an altimetry-derived mesoscale eddy database in the North Atlantic to show that mesoscale cyclones contain 24% more drifters than anticyclones. A numerical Lagrangian experiment using a mesoscale-resolving model quantitatively reproduces the observational results. It reveals that particles preferentially cluster in cyclonic regions, both in fronts and eddies. The model further suggests that ageostrophic cyclonic fronts concentrate particles a few days before the eddy formation and detection.

Keywords: Ocean; mesoscale; clustering; Lagrangian; surface; convergence

Domains: Sciences of the Universe [physics]

Clément Vic, Solenne Hascoët, Jonathan Gula, Christophe Maes, Thierry Huck. Oceanic Mesoscale Cyclones Cluster Surface Lagrangian Material. Geophysical Research Letters, 2022, 49, pp.1-9. ⟨10.1029/2021GL097488⟩. ⟨insu-03683304⟩