The present thesis describes the development of a hybrid behavioural / process-based and wave-averaged model (XBeach Surfbeat) that successfully predicts the recovery of the subaerial beach at Narrabeen Beach, Australia, following a severe storm erosion in April 2015. Two model innovations were developed. Firstly, a behavioural model was developed to predict berm growth during calm conditions, as well as erosion during episodic storm conditions. A second innovation calculates a re-distribution of the sediment transport in the upper swash zone, to account for incident band swash-induced sediment transport, which is not resolved in XBeach Surfbeat, but is of major importance, especially on reflective beaches. The model successfully predicts the behaviour of the beach throughout the recovery period, and shows good potential for long-term simulations.

A freshening of the boundary current (Labrador current and West Greenland Current) supresses deep convection in the Labrador Sea. Furthermore, the fresher water contributes to the ``strength'' of Irminger Rings and increases their life time. This leads to a larger spread of high EKE into the interior of the Labrador Sea and confines the deep convection region more towards the west.