@article{fdi:010080924, title = {{W}hy does the deep western boundary current "{L}eak" around {F}lemish {C}ap ?}, author = {{S}olodoch, {A}. and {M}c{W}illiams, {J}. {C}. and {S}tewart, {A}. {L}. and {G}ula, {J}. and {R}enault, {L}ionel}, editor = {}, language = {{ENG}}, abstract = {{T}he southward-flowing deep limb of the {A}tlantic meridional overturning circulation is composed of both the deep western boundary current ({DWBC}) and interior pathways. {T}he latter are fed by "leakiness' from the {DWBC} in the {N}ewfoundland {B}asin. {H}owever, the cause of this leakiness has not yet been explored mechanistically. {H}ere the statistics and dynamics of the {DWBC} leakiness in the {N}ewfoundland {B}asin are explored using two float datasets and a high-resolution numerical model. {T}he float leakiness around {F}lemish {C}ap is found to be concentrated in several areas (hot spots) that are collocated with bathymetric curvature and steepening. {N}umerical particle advection experiments reveal that the {L}agrangian mean velocity is offshore at these hot spots, while {L}agrangian variability is minimal locally. {F}urthermore, model {E}ulerian mean streamlines separate from the {DWBC} to the interior at the leakiness hot spots. {T}his suggests that the leakiness of {L}agrangian particles is primarily accomplished by an {E}ulerian mean flow across isobaths, though eddies serve to transfer around 50% of the {L}agrangian particles to the leakiness hot spots via chaotic advection, and rectified eddy transport accounts for around 50% of the offshore flow along the southern face of {F}lemish {C}ap. {A}nalysis 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. {T}hese results suggest that mean uncompensated leakiness occurs mostly through inertial separation, for which a scaling analysis is presented. {I}mplications for leakiness of other major boundary current systems are discussed.}, keywords = {{ATLANTIQUE} {NORD} ; {TERRE} {NEUVE} {ET} {LABRADOR}}, booktitle = {}, journal = {{J}ournal of {P}hysical {O}ceanography}, volume = {50}, numero = {7}, pages = {1989--2016}, ISSN = {0022-3670}, year = {2020}, DOI = {10.1175/jpo-d-19-0247.1}, URL = {https://www.documentation.ird.fr/hor/fdi:010080924}, }