Sub‐surface signatures of the Atlantic Multidecadal Oscillation

Sub‐surface signatures of the Atlantic Multidecadal Oscillation (AMO) are identified using expendable bathythermograph (XBT) measurements of temperature from the surface down to a depth of 400 m. Basin averaged temperature anomalies in the North Atlantic at different depths display multidecadal variability with a phase shift between temperature anomalies at the surface and at depth. Westward propagation of temperature anomalies is observable at depth and there is a lag correlation between east‐west and north‐south temperature gradients, with the east‐west temperature gradient leading. These sub‐surface characteristics of the AMO agree with those expected from the noise‐driven internal ocean mode view of the AMO, as derived from a hierarchy of ocean‐atmosphere models.