3-DIMENSIONAL NUMERICAL MODELING OF LATE QUATERNARY PALEOCEANOGRAPHY AND SEDIMENTATION IN THE NORTHERN NORTH-ATLANTIC

Modelling of Late Quaternary paleoceanography and sedimentation in the northern North Atlantic (NNA) is achieved by coupling the ocean gener al circulation model SCINNA (Sensitivity and Circulation In the NNA) t o the sedimentation models SENNA (SEdimentation In the NNA) and PATRIN NA (PArticle TRacing In the NNA). SCINNA is based on the primitive equ ations with conservation of mass, momentum, energy, heat and salt. SEN NA and PATRINNA are driven by temperature, salinity and velocity field s derived from SCINNA. The modelling includes three-dimensional circul ation of the ocean, sediment transport in the water column and two-dim ensional sedimentary processes in a thin bottom layer. SENNA calculate s the erosion, transport and deposition of sediments, resulting in sed imentation patterns for specific time intervals. PATRINNA models the t ransport paths of single sediment grains corresponding to the ocean ci rculation. The NNA reacts in a highly sensitive manner to small forcin g changes, as shown by our sensitivity experiments. From these experim ents it is possible to model specific circulation regimes for glacial and interglacial periods, for melt water events and for the onset of g laciation. The different climatic stages in the circulation model prod uce different sediment patterns in the sedimentation models, which cor respond closely to the sedimentary record.