Structure of the bottom boundary current South of Iceland and spreading
of deep waters by submesoscale processes
Abstract
The northeastern part of the North Atlantic subpolar gyre is a key
passage for the Atlantic Meridional Overturning Circulation upper
cell.
To this day, the precise pathway and intensity of bottom currents in
this area have not reached a consensus.
In this study, we make use of regional high resolution numerical
modeling to suggest that the main bottom current flowing south of
Iceland originates from both the Faroe-Bank Channel and the
Iceland-Faroe Ridge (with about equal contributions) and then flows
along the topographic slope centered.
When flowing over the rough topography, this bottom current generates a
bottom mixed layer reaching 200 m height.
We further demonstrate that many submesoscale structures are generated
at the southernmost tip of the Icelandic shelf, thus spreading water
masses in the open Iceland Basin.
These findings have major implication in the better understanding of the
transport of dense water masses in the North Atlantic.