The Ekman Streamfunction and the Eulerian and Residual Overturning Circulations of the Southern Ocean

Abstract

The Ekman streamfunction is a wind-derived metric that can be used to infer the Southern Ocean overturning circulations (SOOCs) in both latitude-depth and latitude-potential density spaces. The Ekman streamfunction integrates the Ekman pumping zonally and northwards from Antarctica, either to a given latitude or potential density. Here, we evaluate the relationship between the Ekman streamfunction and SOOCs in a global 0. (Formula presented.) ocean-sea-ice model driven by interannual forcing (1958–2018). In certain regions of the Southern Ocean, strong correlations ((Formula presented.)) exist between the Ekman streamfunction and the Eulerian and residual SOOCs on monthly and annual timescales. Regression analysis identifies regions where Ekman streamfunction variability coincides with (Formula presented.) Sv changes in the overturning; one such location is where the wind stress curl changes sign and the Ekman pumping is highly variable. Show more