Anomalous Ekman Transport Near Kerguelen Island

In this study we use data from 8 velocity profiling floatsto examine the wind driven response of the surface layerof the Southern Ocean north of the Kerguelen Plateauduring 2008. Assuming a constant geostrophic velocity within theupper 200m of the ocean we have identified Ekman-likespirals in 249 profiles and in the mean profile.Considering constant geostrophic shear this figureincreased to 455 Ekman spirals. Mean Ekman transport was found to be skewed towardsthe wind, lying at 45 rather than 90 to the left of thewind as expected from steady-state Ekman theory for theSouthern Hemisphere. This downwind transport anomaly was found to displaylittle sensitivity to the presence of geostrophic shear ortransient wind forcing. We suggest that the anomalyresults from the compression‟ observed in the meanspiral, possibly associated with ocean densitystratification.