Oxygen in ml/l along the 1995 I8N with pressure as a vertical coordinate. Dots represent the salinity minumum, marking the extent of AAIW core and low salinity surface waters. Planetary potential vorticity with values less than 60 E-14 (cm s)-1 are shaded: low potential vorticity, high oxygen mode waters are seen near 500-700m depth at the southern end of the section.