Interannual variability in the mesoscale distribution of the depth of the upper boundary of the oxygen minimum layer off northern Chile (18-24S): Implications for the pelagic system and biogeochemical cycling

摘要

The low oxygen concentration (＜2 ml L~-1) at relatively shallow depths (＜100 m) in the coastal upwelling zone and in the adjacent oceanic area is a distinct feature of the eastern boundary Humboldt Current System (HCS) off Peru and northern Chile; it affects the distribution of pelagic Organisms and is associated with an important denitrification regime in the water column. Neverthe- Less, little information is available about the spatial and temporal variability in the distribution of the Oxygen minimum Layer (OML) present in the HCS and the impact of its variability upon the pelagic System and biogeochemical cycles in the region.