FN Archimer Export Format
PT J
TI Why Does the Deep Western Boundary Current “Leak” around Flemish Cap?
BT 
AF Solodoch, Aviv
   McWilliams, James C.
   Stewart, Andrew L.
   Gula, Jonathan
   Renault, Lionel
AS 1:1;2:1;3:1;4:2;5:3;
FF 1:;2:;3:;4:;5:;
C1 Dept. of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, USA
   Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale (LOPS), IUEM, Brest, France
   LEGOS, University of Toulouse, IRD, CNRS, CNES, UPS, Toulouse, France
C2 UNIV CALIF LOS ANGELES, USA
   UBO, FRANCE
   UNIV TOULOUSE, FRANCE
UM LOPS
IN WOS Cotutelle UMR
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
IF 3.373
TC 10
UR https://archimer.ifremer.fr/doc/00630/74184/73787.pdf
LA English
DT Article
AB The southward flowing deep limb of the Atlantic Meridional Overturning Circulation is comprised of both the Deep Western Boundary Current (DWBC) and interior pathways. The latter are fed by “leakiness” from the DWBC in the Newfoundland Basin. However, the cause of this leakiness has not yet been explored mechanistically. Here the statistics and dynamics of the DWBC leakiness in the Newfoundland Basin are explored using two float data sets and a high-resolution numerical model. The float leakiness around Flemish Cap is found to be concentrated in several areas (“hotspots”) that are collocated with bathymetric curvature and steepening. Numerical particle advection experiments reveal that the Lagrangian mean velocity is offshore at these hotspots, while Lagrangian variability is minimal locally. Furthermore, model Eulerian-mean streamlines separate from the DWBC to the interior at the leakiness hotspots. This suggests that the leakiness of Lagrangian particles is primarily accomplished by an Eulerian-mean flow across isobaths, though eddies serve to transfer around 50% of the Lagrangian particles to the leakiness hotspots via chaotic advection, and rectified eddy transport accounts for around 50% of the offshore flow along the Southern Face of Flemish Cap. Analysis of the model’s energy and potential vorticity budgets suggests that the flow is baroclinically unstable after separation, but that the resulting eddies induce modest modifications of the mean potential vorticity along streamlines. These results suggest that mean uncompensated leakiness occurs mostly through inertial separation, for which a scaling analysis is presented. Implications for leakiness of other major boundary current systems are discussed. 
PY 2020
PD JUN
SO Journal Of Physical Oceanography
SN 0022-3670
PU American Meteorological Society
VL 50
IS 7
UT 000617314700010
BP 1989
EP 2016
DI 10.1175/JPO-D-19-0247.1
ID 74184
ER

EF