The relationship between storms and extreme ocean waves in the North Sea is assessed using a long‐period wave data set and storms identified in the Interim ECMWF Re‐Analysis (ERA‐Interim). An ensemble sensitivity analysis is used to provide information on the spatial and temporal forcing from mean sea‐level pressure and surface wind associated with extreme ocean wave height responses. Extreme ocean waves in the central North Sea arise due to intense extratropical cyclone winds from either the cold conveyor belt (northerly‐wind events) or the warm conveyor belt (southerly‐wind events). The largest wave heights are associated with northerly‐wind events which tend to have stronger wind speeds and occur as the cold conveyor belt wraps rearward round the cyclone to the cold side of the warm front. The northerly‐wind events provide a larger fetch to the central North Sea to aid wave growth. Southerly‐wind events are associated with the warm conveyor belts of intense extratropical cyclones that develop in the left upper tropospheric jet exit region. Ensemble sensitivity analysis can provide early warning of extreme wave events by demonstrating a relationship between wave height and high pressure to the west of the British Isles for northerly‐wind events 48 h prior. Southerly‐wind extreme events demonstrate sensitivity to low pressure to the west of the British Isles 36 h prior.

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The present paper describes applications of an integrated numerical modeling system for the study of hydrodynamic conditions in areas with large tidal and surge variations, strong current and very complex bathymetries. The modeling system includes a dynamic coupling between a 2D flow model and a spectral wave model and is based on an unstructured finite volume technique. Two applications are presented: the Bristol Channel, United Kingdom, and Grådyb tidal inlet, Denmark, characterized as macro-and micro-tidal estuaries, respectively. The work demonstrates the advantages of using an unstructured grid approach and that the inclusion of wave-current interaction is mandatory for obtaining accurate results in tidal areas.

[1] The mechanism responsible for asymmetric sediment accretion around an idealized, symmetrical headland is clearly the Coriolis force. What is not evident, however, is how the Coriolis force manifests itself in the headland dynamics to promote asymmetric depositional patterns. In this study, patterns of scour and accretion, topographic and advective vorticity, bed load, and suspended load transport pathways around a theoretical coastal headland are examined. Previous studies have emphasized the contribution of the Coriolis force to a secondary flow mechanism, ''tidal stirring.'' This investigation provides evidence to suggest that secondary flow dynamics are not significant in sandbank generation associated with headlands. It further demonstrates the direct contribution of the Coriolis force in reinforcing inertial terms, near-headland scour, and asymmetric accretion. Examination of the vorticity balance throughout the simulations reveals that high levels of slope-induced topographic vorticity act in direct opposition to advective vorticity near a headland tip. It is also demonstrated that the Coriolis force manifests itself in the production of vorticity. This has been used in the investigation as a means of detecting the sensitivity of the flow to the Coriolis force. In regimes where advective and topographic vorticity production is very similar (flat bed cases), it is found that bed evolution is more sensitive to the Coriolis force. In regimes where topographic vorticity clearly dominates the vorticity balance (in seabed slope case), the influence of the Coriolis force becomes less important.

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