Mesoscale structures as barriers to mixing in the East Tropical Pacific Oxygen Minimum Zone

The oxygen content of sea water is a major factor affecting marine fauna and biogeochemical cycles.
Zones were an oxygen deficit is present in the water column represent significant portions of the total
area and volume of the world's oceans and are thought to be increasing. In the Eastern Tropical Pacific an
oxygen minimum zone is found, maintained primarily by biological processes and weak ventilation and where
equatorial and eastern boundary current systems drive the circulation. The Eastern Tropical Pacific Oxygen
Minimum Zone developed off Peru is populated by mesoscale eddies whose role on the exchange of water mass
properties remains largely unknown. We study this problem from a modeling approach and a Lagrangian point
of view, characterizing pathways and barriers to transport and mixing of oceanic regions with distinct
concentrations of dissolved oxygen. Our results show the crucial role of mesoscale dynamics in the establishment
of the Oxygen Minimum Zone.