Circulation over a submarine canyon in the NW Mediterranean

[1] The circulation in Blanes canyon, an interruption in the NW Mediterranean continental shelf north of Barcelona, was investigated. The study employs data from oceanographic surveys carried out in the summer and fall of 2003. Velocity data show that in the vicinity of the shelf break the flow is deflected along the canyon walls. A cyclonic mean flow can be seen over the canyon mouth owing to vortex stretching of fluid parcels advected across the shelf break. Field observations are in qualitative agreement with fundamental fluid dynamic considerations based on potential vorticity conservation and friction effects at lateral boundaries. Evidence is given that upwelling is found near the shelf break inside the canyon in the two field experiments. This upwelling extends vertically from the seasonal thermocline (at about 100 m) to the shelf-slope front (at about 200 m). There is no evidence that upwelled water can reach the continental shelf.

[1]  J. Klinck.  Circulation near submarine canyons: A modeling study , 1996 .

[2]  V. Heijst,et al.  The behavior of jet currents over a continental slope topography with a possible application to the northern current , 2005 .

[3]  M. Foreman,et al.  Physical and biological processes over a submarine canyon during an upwelling event , 2001 .

[4]  J. Klinck,et al.  Flow near submarine canyons driven by constant winds , 2000 .

[5]  J. Company,et al.  Spatio-temporal variations in megabenthos abundance in three different habitats of the Catalan deep-sea (Western Mediterranean) , 1994 .

[6]  J. Figa,et al.  On the structure of the mean flow in the Blanes Canyon area (NW Mediterranean) during summer , 1993 .

[7]  P. Baines.  Tidal Motion in Submarine Canyons—A Laboratory Experiment , 1983 .

[8]  M. Canals,et al.  A multidisciplinary approach to the understanding of hydromedusan populations inhabiting Mediterranean submarine canyons , 2000 .

[9]  X. D. D. Madron.  Hydrography and nepheloid structures in the Grand-Rhoˆne canyon , 1994 .

[10]  A. Genin.  Bio-physical coupling in the formation of zooplankton and fish aggregations over abrupt topographies , 2004 .

[11]  Joaquín Tintoré,et al.  Flow modification and shelf‐slope exchange induced by a submarine canyon off the northeast Spanish coast , 1996 .

[12]  B. Hickey.  The Response of a Steep-Sided, Narrow Canyon to Time-Variable Wind Forcing , 1997 .

[13]  P. Conan,et al.  Variability of the northern current off Marseilles, western Mediterranean-sea, from February to June 1992 , 1995 .

[14]  Miquel Canals,et al.  Toponímia de la Mar Catalano-Balear , 2014 .

[15]  Jordi Font,et al.  Permanent features of the circulation in the Catalan Sea , 1988 .

[16]  C. Millot.  Circulation in the Western Mediterranean Sea , 1999 .

[17]  M. Pedder,et al.  Errors in dynamical fields inferred from oceanographic cruise data. Part I. The impact of observation errors and the sampling distribution , 2005 .

[18]  A. Sánchez-Arcilla,et al.  Numerical simulation of barotropic jets over a sloping bottom : comparison to a laboratory model of the Northern Current , 2004 .

[19]  P. Baines.  On internal tide generation models , 1982 .

[20]  Manuel Espino,et al.  A field study of the behaviour of an anticyclonic eddy on the Catalan continental shelf (NW Mediterranean) , 2005 .

[21]  M. Tsimplis,et al.  A two‐dimensional tidal model for the Mediterranean Sea , 1995 .

[22]  A. Sabatés,et al.  Variation of larval fish distributions associated with variability in the location of a shelf-slope front , 1996 .

[23]  S. Djenidi,et al.  Shelf‐slope exchanges associated with a steep submarine canyon off Calvi (Corsica, NW Mediterranean Sea): A modeling approach , 2001 .

[24]  J. Font,et al.  On the seasonal and mesoscale variabilities of the Northern Current during the PRIMO-0 experiment in the western Mediterranean-sea , 1995 .

[25]  David C. Smith,et al.  Impulsively Started Flow in a Submarine Canyon: Comparison of Results from Laboratory and Numerical Models* , 2001 .

[26]  G. Basterretxea,et al.  Shelf-slope exchanges by frontal variability in a steep submarine canyon , 2005 .

[27]  I. Palomera.  Spawning of anchovy Engraulis encrasicolus in the Northwestern Mediterranean relative to hydrographic features in the region , 1991 .

[28]  J. Klinck.  The influence of a narrow transverse canyon on initially geostrophic flow , 1988 .

[29]  F. Ardhuin,et al.  Numerical study of the circulation in a steep canyon off the Catalan coast (western Mediterranean) , 1999 .

[30]  F. Bretherton,et al.  A technique for objective analysis and design of oceanographic experiments applied to MODE-73 , 1976 .

[31]  M. Vargas,et al.  Tidal motions and tidally induced fluxes through La Línea submarine canyon, western Alboran Sea , 1999 .

[32]  X. D. D. Madron,et al.  Seasonal variability of the advective transport of particulate matter and organic carbon in the Gulf , 2001 .

[33]  S. Smirnov,et al.  The Effects of Boundary Turbulence on Canyon Flows Forced by Periodic Along-Shelf Currents , 2006 .

[34]  J. Font,et al.  The seasonality of mesoscale motion in the northern current of the western mediterranean - several years of evidence , 1995 .

[35]  J. Font,et al.  Tidal currents in the western mediterranean-sea , 1995 .

[36]  X. D. D. Madron,et al.  Flow variability in the Gulf of Lions during the MATER HFF experiment (March-May 1997) , 2002 .