Search Results
the coupled ASF acts to isolate the cold shelf waters from the warm modified Circumpolar Deep Water (mCDW) offshore ( Whitworth et al. 1998 ). The warm mCDW in the deep ocean flows southward along the density surfaces approaching the continental slope until it rises to a depth comparable to the continental shelf ( Meredith et al. 2011 ). Off Fresh Shelf regions, the ASF is characterized by isopycnals that tilt downward and poleward toward the continental slope ( Orsi and Whitworth 2005 ; Peña
the coupled ASF acts to isolate the cold shelf waters from the warm modified Circumpolar Deep Water (mCDW) offshore ( Whitworth et al. 1998 ). The warm mCDW in the deep ocean flows southward along the density surfaces approaching the continental slope until it rises to a depth comparable to the continental shelf ( Meredith et al. 2011 ). Off Fresh Shelf regions, the ASF is characterized by isopycnals that tilt downward and poleward toward the continental slope ( Orsi and Whitworth 2005 ; Peña
1. Introduction The Naval Research Laboratory has conducted an intensive measurement program of the outer continental shelf and upper slope waters off the Gulf Coast as part of its Slope to Shelf Energetics and Exchange Dynamics (SEED) project ( Mitchell et al. 2005 ; Wang et al. 2005 ; Teague et al. 2006a ). A major goal of SEED is to understand the physical processes that control the exchange of mass, momentum, heat, and water properties across the shelf break. The shelf gently slopes from
1. Introduction The Naval Research Laboratory has conducted an intensive measurement program of the outer continental shelf and upper slope waters off the Gulf Coast as part of its Slope to Shelf Energetics and Exchange Dynamics (SEED) project ( Mitchell et al. 2005 ; Wang et al. 2005 ; Teague et al. 2006a ). A major goal of SEED is to understand the physical processes that control the exchange of mass, momentum, heat, and water properties across the shelf break. The shelf gently slopes from
1. Introduction Deep-water mesoscale anticyclonic eddies interact with continental shelf-slope topography in many parts of the world: for example, the Mid-Atlantic Bight (MAB) off the northeastern United States ( Joyce et al. 1992 ), the Gulf of Alaska ( Okkonen et al. 2003 ), the east Australian shelf ( Tranter et al. 1986 ), and others. At the shelf break, these eddies export shelf water offshore (e.g., Fig. 1 ; Joyce et al. 1992 ) while also transporting eddy and slope waters on to the
1. Introduction Deep-water mesoscale anticyclonic eddies interact with continental shelf-slope topography in many parts of the world: for example, the Mid-Atlantic Bight (MAB) off the northeastern United States ( Joyce et al. 1992 ), the Gulf of Alaska ( Okkonen et al. 2003 ), the east Australian shelf ( Tranter et al. 1986 ), and others. At the shelf break, these eddies export shelf water offshore (e.g., Fig. 1 ; Joyce et al. 1992 ) while also transporting eddy and slope waters on to the
energy propagation of internal waves and dh / dx is the local topographic slope ( N is the local buoyancy frequency, ω is the tidal frequency and f is the Coriolis frequency). For subcritical slopes, presumably much of the energy scatters upslope onto the continental shelf, where it likely dissipates in shallow water, whereas for supercritical slopes an undetermined amount of energy will reflect back into the basin. In both cases, there is presently no method for predicting a priori how much
energy propagation of internal waves and dh / dx is the local topographic slope ( N is the local buoyancy frequency, ω is the tidal frequency and f is the Coriolis frequency). For subcritical slopes, presumably much of the energy scatters upslope onto the continental shelf, where it likely dissipates in shallow water, whereas for supercritical slopes an undetermined amount of energy will reflect back into the basin. In both cases, there is presently no method for predicting a priori how much
1. Introduction Shelfbreak and upper-slope jets (USJs) are relatively common features of the world’s broader continental shelves, being well characterized along the Mid-Atlantic Bight (MAB; e.g., Gawarkiewicz and Chapman 1992 ), the northwest European shelf (e.g., Pingree et al. 1982 ), and in the Arctic along the Beaufort Sea ( Nikolopoulos et al. 2009 ; von Appen and Pickart 2012 ). Density contrasts between the shelf and slope waters force these flows, with topographic steering causing
1. Introduction Shelfbreak and upper-slope jets (USJs) are relatively common features of the world’s broader continental shelves, being well characterized along the Mid-Atlantic Bight (MAB; e.g., Gawarkiewicz and Chapman 1992 ), the northwest European shelf (e.g., Pingree et al. 1982 ), and in the Arctic along the Beaufort Sea ( Nikolopoulos et al. 2009 ; von Appen and Pickart 2012 ). Density contrasts between the shelf and slope waters force these flows, with topographic steering causing
1. Introduction Strong surface cooling generally leads to a deep surface mixed layer because cold, dense surface water creates a gravitationally unstable water column. When this layer reaches to the bottom over the continental shelf, shallower waters cool faster than deeper waters, and a cross-shelf temperature (density) gradient develops. It is well understood from models (e.g., Whitehead 1981 ; Chapman and Gawarkiewicz 1997 ; Pringle 2001 ; Spall 2013 ) that this gradient gives rise to
1. Introduction Strong surface cooling generally leads to a deep surface mixed layer because cold, dense surface water creates a gravitationally unstable water column. When this layer reaches to the bottom over the continental shelf, shallower waters cool faster than deeper waters, and a cross-shelf temperature (density) gradient develops. It is well understood from models (e.g., Whitehead 1981 ; Chapman and Gawarkiewicz 1997 ; Pringle 2001 ; Spall 2013 ) that this gradient gives rise to
coefficients. The main elements of the problem, namely, shelf–slope topography, anticyclonic eddy, and ambient stratification, are all reduced to the simplest possible form. The topography is constructed using three straight lines to bound the shelf, the continental slope, and the deep ocean. The deep-ocean bottom is always flat. A four-point running mean applied six times smooths the intersections at the shelf break and slope break. The term shelf break refers to the intersection of the shelf and
coefficients. The main elements of the problem, namely, shelf–slope topography, anticyclonic eddy, and ambient stratification, are all reduced to the simplest possible form. The topography is constructed using three straight lines to bound the shelf, the continental slope, and the deep ocean. The deep-ocean bottom is always flat. A four-point running mean applied six times smooths the intersections at the shelf break and slope break. The term shelf break refers to the intersection of the shelf and
JULY 1995 H I L L 1617Leakage of Barotropic Slope Currents onto the Continental Shelf A. EDWARD HILLSchool of Ocean Sciences, University of Wales, Bangor, United Kingdom(Manuscript received 17 January 1994, in final form 30 August 1994)ABSTRACT The effect of alongshore variation in continental slope steepness upon the on-shelf penetration of barotropic,slope
JULY 1995 H I L L 1617Leakage of Barotropic Slope Currents onto the Continental Shelf A. EDWARD HILLSchool of Ocean Sciences, University of Wales, Bangor, United Kingdom(Manuscript received 17 January 1994, in final form 30 August 1994)ABSTRACT The effect of alongshore variation in continental slope steepness upon the on-shelf penetration of barotropic,slope
ATW was then used to explore the dynamics of ECS shelf circulation. The ECS has one of the broadest continental shelves in the world, with a width of 400–500 km in the northern and middle parts and then narrowing southward to ~200 km near the Taiwan Island ( Fig. 2a ). The ECS shelf features a double-slope structure in the cross-shelf direction (see the inset in Fig. 2a ). Besides the steep shelf break offshore of the ~120-m isobath, there is also a nearshore slope between the 20- and 60-m
ATW was then used to explore the dynamics of ECS shelf circulation. The ECS has one of the broadest continental shelves in the world, with a width of 400–500 km in the northern and middle parts and then narrowing southward to ~200 km near the Taiwan Island ( Fig. 2a ). The ECS shelf features a double-slope structure in the cross-shelf direction (see the inset in Fig. 2a ). Besides the steep shelf break offshore of the ~120-m isobath, there is also a nearshore slope between the 20- and 60-m
1. Introduction Shelfbreak fronts occur along many continental shelves, such as the northwest Atlantic ( Wright and Parker 1976 ), the Celtic Sea ( Pingree et al. 1982 ), and the southeast Bering Sea ( Coachman 1986 ). These fronts typically separate cool, fresh continental shelf waters from warmer, saltier slope waters and are dynamically trapped along the shelf break where the bottom slope suddenly changes ( Gawarkiewicz and Chapman 1992 ). Shelfbreak fronts are robust features that act as
1. Introduction Shelfbreak fronts occur along many continental shelves, such as the northwest Atlantic ( Wright and Parker 1976 ), the Celtic Sea ( Pingree et al. 1982 ), and the southeast Bering Sea ( Coachman 1986 ). These fronts typically separate cool, fresh continental shelf waters from warmer, saltier slope waters and are dynamically trapped along the shelf break where the bottom slope suddenly changes ( Gawarkiewicz and Chapman 1992 ). Shelfbreak fronts are robust features that act as
