Structure and effects of a long lived vortex in the Greenland Sea

Abstract

Direct observations of the velocity field of a submesoscale coherent vortex in the Greenland Sea by a vessel mounted ADCP, together with a detailed and complete investigation of its hydrographic structure, show that within the eddy the hydrographic structure differs from the background and indicate that the entire water column of 3.7 km depth is included in an anticyclonic rotation with maximum azimuthal speeds at roughly 2000 m depth. Within a radius of about 9 km the water layers rotate in a solid body fashion. The lifetime of the eddy is long enough and the exchange between its interior and the background is small enough to result in a persistent and pronounced anomaly with respect to physical as well as biological parameters. Due to the unique possibility in the high latitudes to 'recharge' the eddy by surface forcing during winter and a corresponding long lifetime such eddies represent key areas for future bottom water production. Copyright 2004 by the American Geophysical Union.