Transport, properties and life-cycles of mesoscale eddies in the eastern tropical South Pacific@en

The influence of mesoscale eddies on the flow field and the water masses, especially the oxygen distribution of the eastern tropical South Pacific is investigated from a mooring, float and satellite data set. Two anticyclonic (ACE1/2), one mode water (MWE) and one cyclonic eddy (CE) are identified and followed in detail with satellite data on their westward transition with velocities of 3.2 to 6.0 cm/s from their generation region, the shelf of the Peruvian and Chilean upwelling regime, across the Stratus Ocean Reference Station (ORS) (~20°S, 85°W) to their decaying region far west in the oligotrophic open ocean. The ORS is located in the transition zone between the oxygen minimum zone and the well-oxygenated South Pacific subtropical gyre. Velocity, hydrographic, and oxygen measurements at the mooring show the impact of eddies on the weak flow region of the eastern tropical South Pacific.