A review of the role of submarine canyons in deep-ocean exchange with the shelf

Abstract. Cross shelf-break exchange is limited by the tendency of geostrophic flow to follow bathymetric contours, not cross them. However, small scale topography, such as canyons, can reduce the local lengthscale of the flow and increase the local Rossby number. These higher Rossby numbers mean the flow is no longer purely geostrophic and significant cross-isobath flow can occur. This cross-isobath flow includes both upwelling and downwelling due to wind-driven shelf currents and the strong cascading flows of dense shelf-water into the ocean. Tidal currents usually run primarily parallel to the shelf-break topography. Canyons cut across these flows and thus are often regions of generation of strong baroclinic tides and internal waves. Canyons can also focus internal waves. Both processes lead to greatly elevated levels of mixing. Thus, through both advection and mixing processes, canyons can enhance Deep Ocean Shelf Exchange. Here we review the state of the science describing the dynamics of the flows and suggest further areas of research, particularly into quantifying fluxes of nutrients and carbon as well as heat and salt through canyons.

[1]  S. Djenidi,et al.  Water fluxes at an ocean margin in the presence of a submarine canyon , 2002 .

[2]  J. Kämpf.  Impact of multiple submarine channels on the descent of dense water at high latitudes , 2000 .

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

[4]  A. Gordon,et al.  Western Ross Sea continental slope gravity currents , 2009 .

[5]  Robert L. Haney,et al.  On the Pressure Gradient Force over Steep Topography in Sigma Coordinate Ocean Models , 1991 .

[6]  I. Fer,et al.  Observations of the Storfjorden overflow , 2003 .

[7]  R. McCauley,et al.  Thermal structure above the Perth Canyon reveals Leeuwin Current, undercurrent and weather influences and the potential for upwelling. , 2006 .

[8]  G. Budillon,et al.  A model for the spreading and sinking of the Deep Ice Shelf Water in the Ross Sea , 2003, Antarctic Science.

[9]  P. Rhines,et al.  Buoyant inhibition of Ekman transport on a slope and its effect on stratified spin-up , 1991, Journal of Fluid Mechanics.

[10]  J. Verron,et al.  Laboratory Simulation of Tidal Rectification over Seamounts: Homogeneous Model , 1991 .

[11]  A. Waterhouse,et al.  Upwelling flow dynamics in long canyons at low Rossby number , 2009 .

[12]  N. Banas,et al.  Why is the northern end of the California Current System so productive , 2008 .

[13]  E. Baker,et al.  Biological and physical processes in and around Astoria submarine Canyon, Oregon, USA , 2004 .

[14]  F. S. Hotchkiss,et al.  Internal waves in Hudson Canyon with possible geological implications , 1982 .

[15]  Humfrey Melling,et al.  Joint effects of wind and ice motion in forcing upwelling in Mackenzie Trough, Beaufort Sea , 2006 .

[16]  G. Williams,et al.  Formation and export of dense shelf water from the Adélie Depression, East Antarctica , 2008 .

[17]  C. Wunsch,et al.  The Climatology of Deep Ocean Internal Waves , 1979 .

[18]  K. Schroeder,et al.  Evidence of a dense water vein along the Libyan continental margin , 2008 .

[19]  S. Allen.  Topographically Generated, Subinertial Flows within A Finite Length Canyon , 1996 .

[20]  D. Yuan.  A numerical study of barotropicly forced intrusion in DeSoto Canyon , 2002 .

[21]  M. Canals,et al.  Dense shelf water cascades and sedimentary furrow formation in the Cap de Creus Canyon, northwestern Mediterranean Sea , 2008 .

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

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

[24]  M. Gačić,et al.  Spatial and Seasonal Variability of Water and Biogeochemical Fluxes in the Adriatic Sea , 1999 .

[25]  J. Doran,et al.  The Relationship between Overlying Synoptic-Scale Flows and Winds within a Valley , 1993 .

[26]  S. Allen,et al.  The influence of canyons on shelf currents: A theoretical study , 1996 .

[27]  G. F. Lane-Serff,et al.  Laboratory observations of enhanced entrainment in dense overflows in the presence of submarine canyons and ridges , 2008 .

[28]  K. Aagaard,et al.  Arctic ocean‐shelf exchange: Measurements in Barrow Canyon , 1990 .

[29]  B. Hickey,et al.  On vertical advection truncation errors in terrain‐following numerical models: Comparison to a laboratory model for upwelling over submarine canyons , 2003 .

[30]  I. Fer,et al.  Observations of hydrography and downflow of brine-enriched shelf water in the Storfjorden polynya, Svalbard , 2008 .

[31]  Robert L. Street,et al.  Numerical simulation of internal tides and the resulting energetics within Monterey Bay and the surrounding area , 2006 .

[32]  S. Allen.  On subinertial flow in submarine canyons: Effect of geometry , 2000 .

[33]  J. Paduan,et al.  Numerical simulations of the internal tide in a submarine canyon , 2002 .

[34]  I. Vilibić,et al.  Dense water generation on a shelf: the case of the Adriatic Sea , 2005 .

[36]  E. Baker,et al.  Suspended particle movement in and around Quinault submarine Canyon , 1986 .

[37]  W. Crawford,et al.  Turbulence and Mixing: Sources of Nutrients on the Vancouver Island Continental Shelf , 1989 .

[38]  E. Darelius.  Topographic steering of dense overflows: Laboratory experiments with V-shaped ridges and canyons , 2008 .

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

[40]  C. Estournel,et al.  Dense shelf water cascading in the northwestern Mediterranean during the cold winter 2005: Quantification of the export through the Gulf of Lion and the Catalan margin , 2008 .

[41]  R. Mirshak,et al.  Spin‐up and the effects of a submarine canyon: Applications to upwelling in Astoria Canyon , 2005 .

[42]  Lawrence J. Pratt,et al.  Flow of winter-transformed Pacific water into the Western Arctic , 2005 .

[43]  Dake Chen,et al.  Tidal effect on the dense water discharge, Part 2: A numerical study , 2009 .

[44]  I. Vilibić,et al.  Deep water ventilation traced by Synechococcus cyanobacteria , 2008 .

[45]  C. Estournel,et al.  Impact of storms and dense water cascading on shelf-slope exchanges in the Gulf of Lion (NW Mediterranean) , 2008 .

[46]  J. Kämpf.  On the Interaction of Time-Variable Flows with a Shelfbreak Canyon , 2009 .

[47]  A. Pascual,et al.  A Quasigeostrophic Analysis of a Meander in the Palamós Canyon: Vertical Velocity, Geopotential Tendency, and a Relocation Technique , 2004 .

[48]  P. Marsaleix,et al.  Three-dimensional modeling of the Gulf of Lion's hydrodynamics (northwest Mediterranean) during January 1999 (MOOGLI3 Experiment) and late winter 1999: Western Mediterranean Intermediate Water's (WIW's) formation and its cascading over the shelf break , 2004 .

[49]  H. Jonkers,et al.  Red Sea gravity currents cascade near-reef phytoplankton to the twilight zone , 2004 .

[50]  Alejandro J. Souza,et al.  The Malin cascade in winter 1996 , 1998 .

[51]  Rob A. Hall,et al.  Internal Tides in Monterey Submarine Canyon , 2002 .

[52]  X. D. D. Madron,et al.  Comments on “Cascades of dense water around the world ocean” , 2005 .

[53]  S. Djenidi,et al.  Plankton dynamics controlled by hydrodynamic processes near a submarine canyon off NW corsican coast: A numerical modelling study , 2006 .

[54]  A. M. Davies,et al.  Modelling processes influencing shelf edge exchange of water and suspended sediment , 2005 .

[55]  D. Chapman,et al.  Offshore transport of dense shelf water in the presence of a submarine canyon , 1995 .

[56]  D. Haidvogel,et al.  Laboratory–Numerical Model Comparisons of Canyon Flows: A Parameter Study , 2003 .

[57]  X. D. D. Madron,et al.  Cascades in Mediterranean Submarine Grand Canyons , 2009 .

[58]  X. D. D. Madron,et al.  Role of the climatological and current variability on shelf-slope exchanges of particulate matter : Evidence from the rhône continental margin (NW Mediterranean) , 1999 .

[59]  Manuel Espino,et al.  Circulation over a submarine canyon in the NW Mediterranean , 2008 .

[60]  Peter D. Killworth,et al.  Deep convection in the World Ocean , 1983 .

[61]  J. Klinck.  Geostrophic Adjustment Over Submarine Canyons , 1989 .

[62]  L. D. Santis.  New insights into submarine geomorphology and depositional processes along the George V Land continental slope and upper rise (East Antarctica) , 2010 .

[63]  Franklin B. Schwing,et al.  Bifurcated flow from an upwelling center: a cold water source for Monterey Bay , 1994 .

[64]  E. Salusti,et al.  On a Sugimoto-Whitehead effect in the Mediterranean sea : sinking and mixing of a bottom current in the Bari Canyon, southern Adriatic sea , 1990 .

[65]  D. Haidvogel.  Cross-Shelf Exchange Driven by Oscillatory Barotropic Currents at an Idealized Coastal Canyon , 2005 .

[66]  D. Quadfasel,et al.  Outflow of dense water from a Svalbard fjord into the Fram Strait , 1988 .

[67]  Albert Palanques,et al.  Flushing submarine canyons , 2006, Nature.

[68]  V. Ivanov,et al.  Cascades of dense water around the world ocean [review article] , 2004 .

[69]  J. Kämpf.  Transient wind‐driven upwelling in a submarine canyon: A process‐oriented modeling study , 2006 .

[70]  S. Chao,et al.  Effects of a baroclinic current on a sinking dense water plume from a submarine canyon and heton shedding , 2003 .

[71]  A. Hay,et al.  Wind and topographic effects on the Labrador Current at Carson Canyon , 1987 .

[72]  Donald J. Cavalieri,et al.  Circulation, dense water formation, and outflow on the northeast Chukchi Shelf , 1998 .

[73]  J. Backhaus,et al.  Sediments in Bottom-Arrested Gravity Plumes: Numerical Case Studies* , 1998 .

[74]  E. Fahrbach,et al.  A dense bottom water plume in the western Barents Sea: downstream modification and interannual variability , 1999 .

[75]  M. Dinniman,et al.  The Influence of Open versus Periodic Alongshore Boundaries on Circulation near Submarine Canyons , 2002 .

[76]  M. Gregg,et al.  Intense, Variable Mixing near the Head of Monterey Submarine Canyon , 2002 .

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

[78]  J. Backhaus,et al.  Sediment-induced slope convection: Two-dimensional numerical case studies , 1999 .

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

[80]  H. Hellmer,et al.  Evidence of deep- and bottom-water formation in the western Weddell Sea , 2008 .

[81]  J. Gómez-Enri,et al.  Observations of internal waves and associated mixing phenomena in the Portimao Canyon area , 2006 .

[82]  D. Haidvogel,et al.  Laboratory–Numerical Model Comparisons of Flow over a Coastal Canyon , 2001 .

[83]  D. Blasco,et al.  General patterns of circulation, sediment fluxes and ecology of the Palamos (La Fonera) submarine canyon, northwestern Mediterranean , 2005 .

[84]  J. Paduan,et al.  Observations of the Internal Tide in Monterey Canyon , 1998 .

[85]  I. Fer,et al.  Descent and mixing of the overflow plume from Storfjord in Svalbard: an idealized numerical model study , 2007 .

[86]  A. Wåhlin,et al.  Downward flow of dense water leaning on a submarine ridge , 2007 .

[87]  A. Wåhlin.  Topographic steering of dense currents with application to submarine canyons , 2002 .

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

[89]  T. Keen,et al.  The generation of internal waves on the continental shelf by Hurricane Andrew , 2000 .

[90]  I. Fer,et al.  Dense overflow from an Arctic fjord: Mean seasonal cycle, variability and wind influence , 2009 .

[91]  R. Muench,et al.  Tides of the northwestern Ross Sea and their impact on dense outflows of Antarctic Bottom Water , 2009 .

[92]  E. Carmack,et al.  Wind‐forced upwelling and internal Kelvin wave generation in Mackenzie Canyon, Beaufort Sea , 1998 .

[93]  D. Boyer,et al.  Laboratory observations of rotating, stratified flow in the vicinity of a submarine canyon , 2000 .

[94]  J. Kämpf.  On the magnitude of upwelling fluxes in shelf-break canyons , 2007 .

[95]  Qiang Wang,et al.  Bottom water formation in the southern Weddell Sea and the influence of submarine ridges: Idealized numerical simulations , 2008 .

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

[97]  S. Allen.  Restrictions on Deep Flow Across the Shelf-break and the Role of Submarine Canyons in Facilitating such Flow , 2004 .

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

[99]  F. Foglini,et al.  The impact of cascading currents on the Bari Canyon System, SW-Adriatic Margin (Central Mediterranean) , 2007 .

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

[101]  I-Huan Lee,et al.  Turbulent mixing and internal tides in Gaoping (Kaoping) Submarine Canyon, Taiwan , 2009 .

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

[103]  D. Chapman.  The influence of an alongshelf current on the formation and offshore transport of dense water from a coastal polynya , 2000 .

[104]  E. Carmack,et al.  Synoptic Flow and Density Observations near an Arctic Shelf Break , 1997 .

[105]  J. Kämpf.  Cascading-driven upwelling in submarine canyons at high latitudes , 2005 .

[106]  J. Klinck,et al.  Estimation of shelf‐slope exchanges induced by frontal instability near submarine canyons , 2008 .

[107]  F. Saucier,et al.  Tidal circulation and buoyancy effects in the St. Lawrence Estuary , 2000 .

[108]  G. Taylor.  Experiments on the motion of solid bodies in rotating fluids , 1923 .

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

[110]  M. Sobarzo,et al.  Upwelling of subsurface water into the rim of the Biobio submarine canyon as a response to surface winds , 2001 .

[111]  A. Wåhlin.  Downward channeling of dense water in topographic corrugations , 2004 .