Modeling sediment drifts: A coupled oceanic circulation‐sedimentation model of the northern North Atlantic

Modeling of sediment drifts in the northern North Atlantic is achieved by coupling the ocean general circulation model sensitivity and circulation in the northern North Atlantic (SCINNA) to the sedimentation models sedimentation in the northern North Atlantic (SENNA) and particle tracing in the northern North Atlantic (PATRINNA). SCINNA is based on the primitive equations with conservation of mass, momentum, heat, and salt. SENNA and PATRINNA are driven by temperature, salinity, and velocity fields derived from SCINNA. Sediments are supplied from the surface and from the continental margins. The modeling includes three‐dimensional sediment transport in the water column and two‐dimensional processes in a thin bottom layer. Sediments are allowed to resuspend repeatedly, thus offering the possibility of stepwise transport. SENNA calculates erosion, transport, and deposition of sediments, resulting in sedimentation patterns for specific time intervals. PATRINNA models the transport paths of single sediment grains corresponding to the ocean circulation. Sensitivity experiments for the modern state and for the last glacial maximum show differences in the large sediment drifts between the Charlie Gibbs Fracture Zone and the Greenland‐Scotland Ridge for these two time slices. The sediment supply changes with the differing circulation modes and is strongly constrained by topography.