An estimate of the eddy-induced circulation in the Labrador Sea

Regions of oceanic deep convection such as the Labrador Sea are prone to baroclinic instability. The resulting geostrophic eddies play a crucial role in the post-convection adjustment process which involves both rearrangement of mass so as to release available potential energy and exchange of heat and salt with the boundaries. In this study it is proposed that the slumping of isopycnals associated with baroclinic instability drives an eddy-induced 'overturning circulation' consisting of a surface intensified flow transporting low salinity water from the boundary currents into the interior; sinking motion in the interior; and an 'outflow' at depth transporting newly ventilated Labrador Sea Water towards the boundaries. Typical eddy-induced velocities estimated from hydrographic data are roughly 0.5 cm/s for the surface inflow, 1 m/day for the vertical motion, and 0.1 cm/s for the deeper outflow, in close agreement with those calculated in a numerical model

How does Labrador Sea Water enter the deep western boundary current?

Author Posting. © American Meteorological Society, 2008. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 38 (2008): 968-983, doi:10.1175/2007JPO3807.1.Labrador Sea Water (LSW), a dense water mass formed by convection in the subpolar North Atlantic, is an important constituent of the meridional overturning circulation. Understanding how the water mass enters the deep western boundary current (DWBC), one of the primary pathways by which it exits the subpolar gyre, can shed light on the continuity between climate conditions in the formation region and their downstream signal. Using the trajectories of (profiling) autonomous Lagrangian circulation explorer [(P)ALACE] floats, operating between 1996 and 2002, three processes are evaluated for their role in the entry of Labrador Sea Water in the DWBC: 1) LSW is formed directly in the DWBC, 2) eddies flux LSW laterally from the interior Labrador Sea to the DWBC, and 3) a horizontally divergent mean flow advects LSW from the interior to the DWBC. A comparison of the heat flux associated with each of these three mechanisms suggests that all three contribute to the transformation of the boundary current as it transits the Labrador Sea. The formation of LSW directly in the DWBC and the eddy heat flux between the interior Labrador Sea and the DWBC may play leading roles in setting the interannual variability of the exported water mass.We are also grateful to the NSF for their support of this research

Additional file 13 of WATLAS: high-throughput and real-time tracking of many small birds in the Dutch Wadden Sea

Additional file 13. Data file with localizations to calculate home ranges for sanderling as shown in Fig. 9A. TAG represents Individual tag identity, TIME is UNIX time (s), X is the X-coordinate of localizations (m, UTM 31N), Y is the Y-coordinate of localizations (m, UTM 31N), NBS is the number of base stations used to calculate localizations, VARX is the Variance in X coordinates, VARY is the Variance in Y coordinates, COVXY is the Covariance between X and Y coordinates, ts is the timestamp (CET), tideID is the tidal cycle identity, tidaltime is the time past high tide (minutes), and waterlevel is the waterlevel at west-terschelling (cm)