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Abstract. We develop and implement a new method to take into account the impact of waves into the 3-D circulation model SYMPHONIE (Marsaleix et al., 2008(Marsaleix et al., , 2009a following the simplified equations of , which use glm2z-RANS theory (Ardhuin et al., 2008c). These adiabatic equations are completed by additional parameterizations of wave breaking, bottom friction and wave-enhanced vertical mixing, making the forcing valid from the surf zone through to the open ocean. The wave forcing is performed by wave generation and propagation models WAVEWATCH III ® (Tolman, 2008(Tolman, , 2009Ardhuin et al., 2010) and SWAN (Booij et al., 1999). The model is tested and compared with other models for a plane beach test case, previously tested by Haas and Warner (2009) Finally, a realistic case is simulated with energetic waves travelling over a coast of the Gulf of Lion (in the northwest of the Mediterranean Sea) for which currents are available at different depths as well as an accurate bathymetric database of the 0-10 m depth range. A grid nesting approach is used to account for the different forcings acting at different spatial scales. The simulation coupling the effects of waves and currents is successful to reproduce the powerful northward littoral drift in the 0-15 m depth zone. More precisely, two distinct cases are identified: When waves have a normal angle of incidence with the coast, they are responsible for complex circulation cells and rip currents in the surf zone, and when they travel obliquely, they generate a northward littoral drift. These features are more complicated than in the test cases, due to the complex bathymetry and the consideration of wind and non-stationary processes. Wave impacts in the inner shelf are less visible since wind and regional circulation seem to be the predominant forcings. Besides, a discrepancy between model and observations is noted at that scale, possibly linked to an underestimation of the wind stress.This three-dimensional method allows a good representation of vertical current profiles and permits the calculation of the shear stress associated with waves and currents. Future work will focus on the combination with a sediment transport model.

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[1] In February 2010, the Mertz Glacier Tongue (MGT) calved, releasing an 80 Â 40 km iceberg. We have developed a high-resolution barotropic ocean model of the region to simulate the local circulation in response to tides and atmospheric forcing. We improved the coastline, grounding line position and built a new bathymetry using satellite imagery and older bathymetry data to derive the best available tidal model for the region. We compared this and other available models to seven different sea level observations available in the area and significantly improved the tidal solutions reaching a root sum square of 2.3 cm. This model was then run in different bathymetric configurations, considering the ice draft of the major icebergs B9B and C28, to simulate the circulation before, during, and after the calving event. The currents changed substantially in the neighborhood of the MGT and icebergs. The barotropic model with tidal and atmospheric forcing and the atmospheric wind fields allow us to evaluate the forces acting on the MGT. The sea surface slope force dominates the budget. Calving occurred when high tide and strong nontidal currents (due to atmospheric forcing) combined to lead to the monthly maximum forces exerted on the MGT (i.e., between 10 and 13 February 2010). While the forces are not unusually large at the calving time, the currents are largely enhanced in the rifting area. Therefore, processes related to these currents, like melting the ice m elange inside the rifts, should be investigated to fully explain the final stage of the calving.

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