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Variability and pathways of Denmark Strait overflow water in subpolar North Atlantic

BCCR/GFI Seminar talk on May 15 by Erik Behrens, NIWA, National Center for Water and Atmospheric Research, Wellington, New Zealand

Body
Erik Behrens

The seminar will take place in the GFI East wing auditorium.

Abstract:

In this study we investigate sources, pathways and transport variability of Denmark Strait overflow water in the Nordic Sea and subpolar North Atlantic in a high resolution model hindcast. Lagrangian particles have been seeded in the Denmark Strait in this simulation and tracked backward and forward in time. Due to the fine model mesh all overflow branches north of Iceland, the shelfbreak EGC, the separated EGC and North Iceland Jet were highly realistic simulated. We were able to confirm the local overturning loop north of Iceland where water of the North Iceland Irminger Current is transformed into overflow water and feeds the North Icelandic Jet. The transport variability of those branches, across the Kögur section, from seasonal to interannual timescales, has been investigated and mean values agree with existing observations. Local wind stress anomalies have been identified to be the main driver for variability. Especially the wind stress curl south of Iceland shows strong correlations to the transport variability and suggested a close connection to the NAO on interannual time scales.