Variability of Antarctic intermediate water properties in the South Pacific Ocean

Abstract. Argo float time series data are used to study the salinity field at the depth of the salinity minimum produced by Antarctic Intermediate Water (AAIW). It is found that far from showing the smooth erosion of the minimum that would result from diffusive flow, the salinity field is characterized by features of geostrophic turbulence such as fronts, eddies and intrusions. Comparison of the Argo float observations with the climatology of the World Ocean Atlas (WOA) reveals significant differences between the two data sets. Some of the differences may have their origin in problems with the WOA data density in remote regions of the South Pacific, but most are more likely produced by interannual variations of the AAIW salinity field.