Journal articles: 'Western boundary current separation'

1

Baines, Peter G., and Roger L. Hughes. "Western Boundary Current Separation: Inferences from a Laboratory Experiment." Journal of Physical Oceanography 26, no. 12 (December 1996): 2576–88. http://dx.doi.org/10.1175/1520-0485(1996)026<2576:wbcsif>2.0.co;2.

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Sakamoto, Toshihiro. "Western Boundary Current Separation Caused by a Deep Countercurrent." Geophysical & Astrophysical Fluid Dynamics 96, no. 3 (January 2002): 179–99. http://dx.doi.org/10.1080/03091920290020977.

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Munday, David R., and David P. Marshall. "On the Separation of a Barotropic Western Boundary Current from a Cape." Journal of Physical Oceanography 35, no. 10 (October 1, 2005): 1726–43. http://dx.doi.org/10.1175/jpo2783.1.

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Abstract The problem of western boundary current separation is investigated using a barotropic vorticity model. Specifically, a boundary current flowing poleward along a boundary containing a cape is considered. The meridional gradient of the Coriolis parameter (the β effect), the strength of dissipation, and the geometry of the cape are varied. It is found that 1) all instances of flow separation are coincident with the presence of a flow deceleration, 2) an increase in the strength of the β effect is able to suppress flow separation, and 3) increasing coastline curvature can overcome the suppressive β effect and induce separation. These results are supported by integrated vorticity budgets, which attribute the acceleration of the boundary current to the β effect and changes in flow curvature. The transition to unsteady final model states is found to have no effect upon the qualitative nature of these conclusions.

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4

Cessi, Paola. "Laminar separation of colliding western boundary currents." Journal of Marine Research 49, no. 4 (November 1, 1991): 697–717. http://dx.doi.org/10.1357/002224091784995738.

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Adamec, David. "Western Boundary Current Separation Sensitivity Studies Using a Quasigeostrophic Ocean Model." Journal of Physical Oceanography 27, no. 5 (May 1997): 798–809. http://dx.doi.org/10.1175/1520-0485(1997)027<0798:wbcsss>2.0.co;2.

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Kiss, Andrew E. "Potential vorticity "crises", adverse pressure gradients, and western boundary current separation." Journal of Marine Research 60, no. 6 (November 1, 2002): 779–803. http://dx.doi.org/10.1357/002224002321505138.

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Schaeffer, Amandine, Moninya Roughan, and Bradley D. Morris. "Cross-Shelf Dynamics in a Western Boundary Current Regime: Implications for Upwelling." Journal of Physical Oceanography 43, no. 5 (May 1, 2013): 1042–59. http://dx.doi.org/10.1175/jpo-d-12-0177.1.

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Abstract The cross-shelf dynamics up- and downstream of the separation of the South Pacific Ocean’s Western Boundary Current (WBC) are studied using two years of high-resolution velocity and temperature measurements from mooring arrays. The shelf circulation is dominated by the East Australian Current (EAC) and its eddy field, with mean poleward depth-integrated magnitudes on the shelf break of 0.35 and 0.15 m s−1 up- and downstream of the separation point, respectively. The high cross-shelf variability is analyzed though a momentum budget, showing a dominant geostrophic balance at both locations. Among the secondary midshelf terms, the bottom stress influence is higher upstream of the separation point while the wind stress is dominant downstream. This study investigates the response of the velocity and temperature cross-shelf structure to both wind and EAC intrusions. Despite the deep water (up to 140 m), the response to a dominant along-shelf wind stress forcing is a classic two-layer Ekman structure. During weak winds, the shelf encroachment of the southward current drives an onshore Ekman flow in the bottom boundary layer. Both the bottom velocity and the resultant bottom cross-shelf temperature gradient are proportional to the magnitude of the encroaching current, with similar linear regressions up- and downstream of the WBC separation. The upwelled water is then subducted below the EAC upstream of the separation point. Such current-driven upwelling is shown to be the dominant driver of cold water uplift in the EAC-dominated region, with significant impacts expected on nutrient enrichment and thus on biological productivity.

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Solodoch, Aviv, James C. McWilliams, Andrew L. Stewart, Jonathan Gula, and Lionel Renault. "Why Does the Deep Western Boundary Current “Leak” around Flemish Cap?" Journal of Physical Oceanography 50, no. 7 (July 1, 2020): 1989–2016. http://dx.doi.org/10.1175/jpo-d-19-0247.1.

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AbstractThe southward-flowing deep limb of the Atlantic meridional overturning circulation is composed 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 datasets and a high-resolution numerical model. The float leakiness around Flemish Cap is found to be concentrated in several areas (hot spots) that are collocated with bathymetric curvature and steepening. Numerical particle advection experiments reveal that the Lagrangian mean velocity is offshore at these hot spots, while Lagrangian variability is minimal locally. Furthermore, model Eulerian mean streamlines separate from the DWBC to the interior at the leakiness hot spots. 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 hot spots 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.

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Pichevin, Thierry, Steven Herbette, and France Floc’h. "Eddy Formation and Shedding in a Separating Boundary Current." Journal of Physical Oceanography 39, no. 8 (August 1, 2009): 1921–34. http://dx.doi.org/10.1175/2009jpo4151.1.

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Abstract This study deals with the separation of western boundary currents within a reduced-gravity framework, and it analyzes the formation of eddies in the separation region and the conditions of their shedding into the open ocean. It shows that the separation point of the current oscillates along the coast so that the retroflected eastward current develops meanders. These meanders grow, drift westward under the influence of β, and finally hit the coastal current, which leads to the periodic formation of eddies. This study also highlights the impact by the geometrical configurations of the flow and coastline upon the existence or lack of a subsequent shedding of these eddies: a shedding occurs when no obstacle hinders the β-induced westward drift of the eddies. This happens when either (i) the current retroflects far enough beyond the tip of the coast so that, because of β, the eddies can propagate westward without being blocked, or (ii) the tilt of the coast is small enough so that the alongshore component of the β-induced velocity is enhanced and the eddies can escape from the retroflection region.

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Pérez-Brunius, Paula, Heather Furey, Amy Bower, Peter Hamilton, Julio Candela, Paula García-Carrillo, and Robert Leben. "Dominant Circulation Patterns of the Deep Gulf of Mexico." Journal of Physical Oceanography 48, no. 3 (March 2018): 511–29. http://dx.doi.org/10.1175/jpo-d-17-0140.1.

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AbstractThe large-scale circulation of the bottom layer of the Gulf of Mexico is analyzed, with special attention to the historically least studied western basin. The analysis is based on 4 years of data collected by 158 subsurface floats parked at 1500 and 2500 m and is complemented with data collected by current meter moorings in the western basin during the same period. Three main circulation patterns stand out: a cyclonic boundary current, a cyclonic gyre in the abyssal plain, and the very high eddy kinetic energy observed in the eastern Gulf. The boundary current and the cyclonic gyre appear as distinct features, which interact in the western tip of the Yucatan shelf. The persistence and continuity of the boundary current is addressed. Although high variability is observed, the boundary flow serves as a pathway for water to travel around the western basin in approximately 2 years. An interesting discovery is the separation of the boundary current over the northwestern slope of the Yucatan shelf. The separation and retroflection of the along-slope current appears to be a persistent feature and is associated with anticyclonic eddies whose genesis mechanism remains to be understood. As the boundary flow separates, it feeds into the westward flow of the deep cyclonic gyre. The location of this gyre—named the Sigsbee Abyssal Gyre—coincides with closed geostrophic contours, so eddy–topography interaction via bottom form stresses may drive this mean flow. The contribution to the cyclonic vorticity of the gyre by modons traveling under Loop Current eddies is discussed.

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11

Sheremet, Vitalii A., and Joseph Kuehl. "Gap-Leaping Western Boundary Current in a Circular Tank Model." Journal of Physical Oceanography 37, no. 6 (June 1, 2007): 1488–95. http://dx.doi.org/10.1175/jpo3069.1.

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Abstract An oceanographically generic problem of the interaction of a boundary current with bathymetric features such as a gap in the ridge or a strait between two islands is considered. Multiple flow patterns (penetrating or leaping the gap) and hysteresis (dependence on prior evolution) may exist in such systems. Examples include the Gulf Stream leaping from the Yucatan to Florida and the Kuroshio leaping from Luzon to Taiwan. Using numerical analysis, Sheremet earlier found that multiple steady states can be explained by variation in the balance between the inertia (which promotes leaping state) and the β effect (which promotes penetrating state). In the present work a verification of the multiple states and hysteresis in a laboratory model are offered. To set up a gap-leaping current, a circular tank with a sloping bottom (simulating the β effect) is used, and the flow is driven using a new method of pumping fluid through sponges (thus generating a Sverdrup flow in the interior). A semicircular ridge with a gap is inserted into the western part of the tank. Using a dye release flow visualization method, the existence of multiple flow patterns over varying boundary current transport values differing by a factor of more than 2 are dramatically shown. An associated numerical model in bipolar curvilinear coordinates, which allows for the matching of all the boundaries, reproduces the laboratory results very well. This idealized problem offers a very useful geophysical test case for numerical models involving flow separation and reattachment.

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12

Verron, J., and E. Blayo. "The No-Slip Condition and Separation of Western Boundary Currents." Journal of Physical Oceanography 26, no. 9 (September 1996): 1938–51. http://dx.doi.org/10.1175/1520-0485(1996)026<1938:tnscas>2.0.co;2.

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13

GRIFFITHS, ROSS W., and ANDREW E. KISS. "Flow regimes in a wide ‘sliced-cylinder’ model of homogeneous beta-plane circulation." Journal of Fluid Mechanics 399 (November 25, 1999): 205–36. http://dx.doi.org/10.1017/s0022112099006370.

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We report new experiments with the ‘sliced-cylinder’ β-plane model of Pedlosky & Greenspan (1967) and Beardsley (1969), but with a much wider basin such that the western boundary current and its eddies occupy a small fraction of the basin width. These experiments provide new insights into nonlinear aspects of the flow: the critical conditions for boundary current separation and the transition from stable to unstable flow are redefined, and a further transition from periodic to chaotic eddy shedding under strong anticyclonic forcing is also found. In the nonlinear regimes the western boundary current separates from the western wall and shoots into the interior as a narrow jet that undergoes a rapid adjustment to join with the broad slow interior flow. In the unstable regimes this adjustment involves eddy shedding. Each transition occurs at a fixed critical value of a Reynolds number Reγ based on the velocity and width scales for a purely viscous boundary current: the flow is unstable for Reγ > 123±4 and aperiodic for Reγ > 231±5. The results provide evidence that the mechanism causing instability is shear in the separated jet rather than the breaking of a large-amplitude Rossby wave. A quasi-geostrophic numerical model applied to the laboratory conditions yields a stability boundary and detailed characteristics of the flow largely consistent with those determined from the experiments. It also reveals a strong dependence of the circulation pattern on basin aspect ratio, and shows that an adverse higher-order pressure gradient is responsible for western boundary current separation in this model. Eddy–eddy interactions and feedback of fluctuations from the eddy formation region to upstream parts of the boundary current contribute to aperiodic behaviour. As a result of eddy shedding, passive tracer from each streamline in the boundary current can be stirred across much of the width of the basin.

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14

Martin, Paige E., Brian K. Arbic, Andrew McC. Hogg, Andrew E. Kiss, James R. Munroe, and Jeffrey R. Blundell. "Frequency-Domain Analysis of the Energy Budget in an Idealized Coupled Ocean–Atmosphere Model." Journal of Climate 33, no. 2 (January 15, 2020): 707–26. http://dx.doi.org/10.1175/jcli-d-19-0118.1.

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AbstractClimate variability is investigated by identifying the energy sources and sinks in an idealized, coupled, ocean–atmosphere model, tuned to mimic the North Atlantic region. The spectral energy budget is calculated in the frequency domain to determine the processes that either deposit energy into or extract energy from each fluid, over time scales from one day up to 100 years. Nonlinear advection of kinetic energy is found to be the dominant source of low-frequency variability in both the ocean and the atmosphere, albeit in differing layers in each fluid. To understand the spatial patterns of the spectral energy budget, spatial maps of certain terms in the spectral energy budget are plotted, averaged over various frequency bands. These maps reveal three dynamically distinct regions: along the western boundary, the western boundary current separation, and the remainder of the domain. The western boundary current separation is found to be a preferred region to energize oceanic variability across a broad range of time scales (from monthly to decadal), while the western boundary itself acts as the dominant sink of energy in the domain at time scales longer than 50 days. This study paves the way for future work, using the same spectral methods, to address the question of forced versus intrinsic variability in a coupled climate system.

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15

Tansley, Claire E., and David P. Marshall. "On the influence of bottom topography and the Deep Western Boundary Current on Gulf Stream separation." Journal of Marine Research 58, no. 2 (March 1, 2000): 297–325. http://dx.doi.org/10.1357/002224000321511179.

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16

Cherniawsky, Josef, and Greg Holloway. "On western boundary current separation in an upper ocean general circulation model of the north Pacific." Journal of Geophysical Research 98, no. C12 (1993): 22843. http://dx.doi.org/10.1029/93jc02296.

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Ribbat, Nina, Moninya Roughan, Brian Powell, Shivanesh Rao, and Colette Gabrielle Kerry. "Transport variability over the Hawkesbury Shelf (31.5–34.5°S) driven by the East Australian Current." PLOS ONE 15, no. 11 (November 5, 2020): e0241622. http://dx.doi.org/10.1371/journal.pone.0241622.

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The Hawkesbury Bioregion located off southeastern Australia (31.5–34.5oS) is a region of highly variable circulation. The region spans the typical separation point of the East Australian Current (EAC), the western boundary current that dominates the flow along the coast of SE Australia. It lies adjacent to a known ocean warming hotspot in the Tasman Sea, and is a region of high productivity. However, we have limited understanding of the circulation, temperature regimes and shelf transport in this region, and the drivers of variability. We configure a high resolution (750m) numerical model for the Hawkesbury Shelf region nested inside 2 data assimilating models of decreasing resolution, to obtain the best estimate of the shelf circulation and transport over a 2-yr period (2012–2013). Here we show that the transport is driven by the mesoscale EAC circulation that strengthens in summer and is related to the separation of the EAC jet from the coast. Transport estimates show strong offshore export is a maximum between 32-33oS. Median offshore transports range 2.5–8.4Sv seasonally and are a maximum during in summer driven by the separation of the EAC jet from the coast. The transport is more variable downstream of the EAC separation, driven by the EAC eddy field. Onshore transport occurs more frequently off Sydney 33.5–34.5oS; seasonal medians range -1.7 to 2.3Sv, with an onshore maximum in winter. The region is biologically productive, and it is a known white shark nursery area despite the dominance of the oligotrophic western boundary current. Hence an understanding of the drivers of circulation and cross-shelf exchange is important.

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Pierini, Stefano, Pierpaolo Falco, Giovanni Zambardino, Thomas A. McClimans, and Ingrid Ellingsen. "A Laboratory Study of Nonlinear Western Boundary Currents, with Application to the Gulf Stream Separation due to Inertial Overshooting*." Journal of Physical Oceanography 41, no. 11 (November 1, 2011): 2063–79. http://dx.doi.org/10.1175/2011jpo4514.1.

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Abstract Various dynamical aspects of nonlinear western boundary currents (WBCs) have been investigated experimentally through physical modeling in a 5-m-diameter rotating basin. The motion of a piston with a velocity up that can be as low as up = 0.5 mm s−1 induces a horizontally unsheared current of homogeneous water that, flowing over a topographic beta slope, experiences westward intensification. First, the character of WBCs for various degrees of nonlinearity is investigated. By varying up, flows ranging from the highly nonlinear inertial Charney regime down to a weakly nonlinear regime can be simulated. In the first case, the dependence of zonal length scales on up is found to be in agreement with Charney’s theory; for weaker flows, a markedly different functional dependence emerges describing the initial transition toward the linear, viscous case. This provides an unprecedented coverage of nonlinear WBC dependence on an amplitude parameter in terms of experimental data. WBC separation from a wedge-shaped continent past a cape (simulating Cape Hatteras) due to inertial overshooting is then analyzed. By increasing current speed, a critical behavior is identified according to which a very small change of up marks the transition from a WBC that follows the coast past the cape to a WBC (nearly dynamically similar to a full-scale Gulf Stream) that separates from the cape without any substantial deflection, as with the Gulf Stream Extension. The important effect of the deflection angle of the continent is analyzed as well. Finally, the qualitative effect of a sloping sidewall along a straight coast is considered: the deflection of the flow away from the western wall due to the tendency to preserve potential vorticity clearly emerges.

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Sijp, Willem P., Jonathan M. Gregory, Remi Tailleux, and Paul Spence. "The Key Role of the Western Boundary in Linking the AMOC Strength to the North–South Pressure Gradient." Journal of Physical Oceanography 42, no. 4 (April 1, 2012): 628–43. http://dx.doi.org/10.1175/jpo-d-11-0113.1.

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Abstract A key idea in the study of the Atlantic meridional overturning circulation (AMOC) is that its strength is proportional to the meridional density gradient or, more precisely, to the strength of the meridional pressure gradient. A physical basis that would indicate how to estimate the relevant meridional pressure gradient locally from the density distribution in numerical ocean models to test such an idea has been lacking however. Recently, studies of ocean energetics have suggested that the AMOC is driven by the release of available potential energy (APE) into kinetic energy (KE) and that such a conversion takes place primarily in the deep western boundary currents. In this paper, the authors develop an analytical description linking the western boundary current circulation below the interface separating the North Atlantic Deep Water (NADW) and Antarctic Intermediate Water (AAIW) to the shape of this interface. The simple analytical model also shows how available potential energy is converted into kinetic energy at each location and that the strength of the transport within the western boundary current is proportional to the local meridional pressure gradient at low latitudes. The present results suggest, therefore, that the conversion rate of potential energy may provide the necessary physical basis for linking the strength of the AMOC to the meridional pressure gradient and that this could be achieved by a detailed study of the APE to KE conversion in the western boundary current.

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Lu, Wenfang, Lie-Yauw Oey, Enhui Liao, Wei Zhuang, Xiao-Hai Yan, and Yuwu Jiang. "Physical modulation to the biological productivity in the summer Vietnam upwelling system." Ocean Science 14, no. 5 (October 24, 2018): 1303–20. http://dx.doi.org/10.5194/os-14-1303-2018.

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Abstract. Biological productivity in the summer Vietnam boundary upwelling system in the western South China Sea, as in many coastal upwelling systems, is strongly modulated by wind. However, the role of ocean circulation and mesoscale eddies has not been elucidated. Here, we show a close spatiotemporal covariability between primary production and kinetic energy. High productivity is associated with high kinetic energy, which accounts for ∼15 % of the production variability. Results from a physical–biological coupled model reveal that the elevated kinetic energy is linked to the strength of the current separation from the coast. In the low production scenario, the circulation is not only weaker but also shows weak separation. In the higher production case, the separated current forms an eastward jet into the interior South China Sea, and the associated southern recirculation traps nutrients and favors productivity. When separation is absent, the model shows weakened circulation and eddy activity, with ∼21 % less nitrate inventory and ∼16 % weaker primary productivity.

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Zharkov, Volodymyr, and Doron Nof. "Why Does the North Brazil Current Regularly Shed Rings but the Brazil Current Does Not?" Journal of Physical Oceanography 40, no. 2 (February 1, 2010): 354–67. http://dx.doi.org/10.1175/2009jpo4246.1.

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Abstract Both the North Brazil Current (NBC) and the Brazil Current (BC) are western boundary currents (WBCs) that separate from the western Atlantic coast. The NBC retroflects and sheds several rings per year (at the retroflection region), whereas the BC rarely sheds rings near its separation point. Traditionally, the difference between these two WBCs has been attributed to the Malvinas Current (MC), whose momentum flux opposes the poleward momentum flux of the BC, thus preventing rings shedding at the point where the current leaves the coast. Even in the absence of the MC, rings from the separating BC would have never been regularly generated because of the relatively large slant of the coastline relative to the zonal direction. Using the recently proposed theory of Zharkov and Nof, it is demonstrated that the large inclination of the coastline between 20° and 45°S (approximately 50°) lies within the regime that does not allow the BC a continuous shedding of rings. In contrast, the inclination of the coastline between 5° and 8°N is sufficiently small to allow the NBC a continuous and smooth shedding of rings. The importance of the coastline inclination comes about through a ring β-induced westward propagation rate. In the small inclination case, the alongshore migration is fast, allowing the newly formed rings to quickly escape from their generation zone (i.e., before they are recaptured by the newly born rings generated behind). In contrast, in the high inclination case, the alongshore speed is so small that the rings spend a long time in the generation area and, consequently, are usually recaptured by the new rings generated just behind them. The authors argue, paradoxically, that the rings occasionally shed by the BC are probably due to the MC that advects the rings away from the generation area, preventing their recapture by the current behind them. Although no new analytical solutions are presented, the authors elaborate on the application of the recapturing condition to the NBC and BC and show new numerical simulations for both the NBC and the BC.

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Wijesekera, Hemantha W., Joel C. Wesson, David W. Wang, William J. Teague, and Z. R. Hallock. "Observations of Flow Separation and Mixing around the Northern Palau Island/Ridge." Journal of Physical Oceanography 50, no. 9 (September 1, 2020): 2529–59. http://dx.doi.org/10.1175/jpo-d-19-0291.1.

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AbstractTurbulent mixing adjacent to the Velasco Reef and Kyushu–Palau Ridge, off northern Palau in the western equatorial Pacific Ocean, is examined using shipboard and moored observations. The study focuses on a 9-day-long, ship-based microstructure and velocity survey, conducted in November–December 2016. Several sections (9–15 km in length) of microstructure, hydrographic, and velocity fields were acquired over and around the reef, where water depths ranged from 50 to 3000 m. Microstructure profiles were collected while steaming slowly either toward or away from the reef, and underway current surveys were conducted along quasi-rectangular boxes with side lengths of 5–10 km. Near the reef, both tidal and subtidal motions were important, while subtidal motions were stronger away from the reef. Vertical shears of currents and mixing were stronger on the northern and eastern flanks of the reef than on the western flanks. High turbulent kinetic energy dissipation rates, 10−6–10−4 W kg−1, and large values of eddy diffusivities, 10−4–10−2 m2 s−1, with strong turbulent heat fluxes, 100–500 W m−2, were found. Currents flowing along the eastern side separated at the northern tip of the reef and generated submesoscale cyclonic vorticity of about 2–4 times the planetary vorticity. The analysis suggests that a torque, imparted by the turbulent bottom stress, generated the cyclonic vorticity at the northern boundary. The northern reef is associated with high vertical transports resulting from both submesoscale flow convergences and energetic mixing. Even though the area around Palau represents a small footprint of the ocean, vertical velocities and mixing rates are several orders magnitude larger than in the open ocean.

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Schoonover, Joseph, William K. Dewar, Nicolas Wienders, and Bruno Deremble. "Local Sensitivities of the Gulf Stream Separation." Journal of Physical Oceanography 47, no. 2 (February 2017): 353–73. http://dx.doi.org/10.1175/jpo-d-16-0195.1.

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AbstractRobust and accurate Gulf Stream separation remains an unsolved problem in general circulation modeling whose resolution will positively impact the ocean and climate modeling communities. Oceanographic literature does not face a shortage of plausible hypotheses that attempt to explain the dynamics of the Gulf Stream separation, yet a single theory that the community agrees on is missing. In this paper, the authors investigate the impact of the deep western boundary current (DWBC), coastline curvature, and continental shelf steepening on the Gulf Stream separation within regional configurations of the Massachusetts Institute of Technology General Circulation Model. Artificial modifications to the regional bathymetry are introduced to investigate the sensitivity of the separation to each of these factors. Metrics for subsurface separation detection confirm the direct link between flow separation and the surface expression of the Gulf Stream in the Mid-Atlantic Bight. It is shown that the Gulf Stream separation and mean surface position are most sensitive to the continental slope steepening, consistent with a theory proposed by Melvin Stern in 1998. In contrast, the Gulf Stream separation exhibits minimal sensitivity to the presence of the DWBC and coastline curvature. The implications of these results to the development of a “separation recipe” for ocean modeling are discussed. This study concludes adequate topographic resolution is a necessary, but not sufficient, condition for proper Gulf Stream separation.

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Zhao, Jian, and William Johns. "Wind-Driven Seasonal Cycle of the Atlantic Meridional Overturning Circulation." Journal of Physical Oceanography 44, no. 6 (May 28, 2014): 1541–62. http://dx.doi.org/10.1175/jpo-d-13-0144.1.

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Abstract The dynamical processes governing the seasonal cycle of the Atlantic meridional overturning circulation (AMOC) are studied using a variety of models, ranging from a simple forced Rossby wave model to an eddy-resolving ocean general circulation model. The AMOC variability is decomposed into Ekman and geostrophic transport components, which reveal that the seasonality of the AMOC is determined by both components in the extratropics and dominated by the Ekman transport in the tropics. The physics governing the seasonal fluctuations of the AMOC are explored in detail at three latitudes (26.5°N, 6°N, and 34.5°S). While the Ekman transport is directly related to zonal wind stress seasonality, the comparison between different numerical models shows that the geostrophic transport involves a complex oceanic adjustment to the wind forcing. The oceanic adjustment is further evaluated by separating the zonally integrated geostrophic transport into eastern and western boundary currents and interior flows. The results indicate that the seasonal AMOC cycle in the extratropics is controlled mainly by local boundary effects, where either the western or eastern boundary can be dominant at different latitudes, while in the northern tropics it is the interior flow and its lagged compensation by the western boundary current that determine the seasonal AMOC variability.

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Hogg, Andrew Mc C., William K. Dewar, Pavel Berloff, Sergey Kravtsov, and David K. Hutchinson. "The Effects of Mesoscale Ocean–Atmosphere Coupling on the Large-Scale Ocean Circulation." Journal of Climate 22, no. 15 (August 1, 2009): 4066–82. http://dx.doi.org/10.1175/2009jcli2629.1.

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Abstract Small-scale variation in wind stress due to ocean–atmosphere interaction within the atmospheric boundary layer alters the temporal and spatial scale of Ekman pumping driving the double-gyre circulation of the ocean. A high-resolution quasigeostrophic (QG) ocean model, coupled to a dynamic atmospheric mixed layer, is used to demonstrate that, despite the small spatial scale of the Ekman-pumping anomalies, this phenomenon significantly modifies the large-scale ocean circulation. The primary effect is to decrease the strength of the nonlinear component of the gyre circulation by approximately 30%–40%. This result is due to the highest transient Ekman-pumping anomalies destabilizing the flow in a dynamically sensitive region close to the western boundary current separation. The instability of the jet produces a flux of potential vorticity between the two gyres that acts to weaken both gyres.

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Waterman, Stephanie, and Steven R. Jayne. "Eddy-Mean Flow Interactions in the Along-Stream Development of a Western Boundary Current Jet: An Idealized Model Study." Journal of Physical Oceanography 41, no. 4 (April 2011): 682–707. http://dx.doi.org/10.1175/2010jpo4477.1.

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A theoretical study on the role of eddy-mean flow interactions in the time-mean dynamics of a zonally evolving, unstable, strongly inertial jet in a configuration and parameter regime that is relevant to oceanic western boundary current (WBC) jets is described. Progress is made by diagnosing the eddy effect on the time-mean circulation, examining the mechanism that permits the eddies to drive the time-mean recirculation gyres, and exploring the dependence of the eddy effect on system parameters. It is found that the nature of the eddy-mean flow interactions in this idealized configuration is critically dependent on along-stream position, in particular relative to the along-stream evolving stability properties of the time-mean jet. Just after separation from the western boundary, eddies act to stabilize the jet through downgradient fluxes of potential vorticity (PV). Downstream of where the time-mean jet has (through the effect of the eddies) been stabilized, eddies act to drive the time-mean recirculations through the mechanism of an upgradient PV flux. This upgradient flux is permitted by an eddy enstrophy convergence downstream of jet stabilization, which results from the generation of eddies in the upstream region where the jet is unstable, the advection of that eddy activity along stream by the jet, and the dissipation of the eddies in the region downstream of jet stabilization. It is in this region of eddy decay that eddies drive the time-mean recirculations through the mechanism of nonlinear eddy rectification, resulting from the radiation of waves from a localized region. It is found that similar mechanisms operate in both barotropic and baroclinic configurations, although differences in the background PV gradient on which the eddies act implies that the recirculation-driving mechanism is more effective in the baroclinic case. This study highlights the important roles that eddies play in the idealized WBC jet dynamics considered here of stabilizing the jet and driving the flanking recirculations. In the absence of eddy terms, the magnitude of the upper-ocean jet transport would be significantly less and the abyssal ocean recirculations (and their significant enhancement to the jet transport) would be missing altogether.

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Bower, Amy S., William E. Johns, David M. Fratantoni, and Hartmut Peters. "Equilibration and Circulation of Red Sea Outflow Water in the Western Gulf of Aden*." Journal of Physical Oceanography 35, no. 11 (November 1, 2005): 1963–85. http://dx.doi.org/10.1175/jpo2787.1.

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Abstract Hydrographic, direct velocity, and subsurface float observations from the 2001 Red Sea Outflow Experiment (REDSOX) are analyzed to investigate the gravitational and dynamical adjustment of the Red Sea Outflow Water (RSOW) where it is injected into the open ocean in the western Gulf of Aden. During the winter REDSOX cruise, when outflow transport was large, several intermediate-depth salinity maxima (product waters) were formed from various bathymetrically confined branches of the outflow plume, ranging in depth from 400 to 800 m and in potential density from 27.0 to 27.5 σθ, a result of different mixing intensity along each branch. The outflow product waters were not dense enough to sink to the seafloor during either the summer or winter REDSOX cruises, but analysis of previous hydrographic and mooring data and results from a one-dimensional plume model suggest that they may be so during wintertime surges of strong outflow currents, or about 20% of the time during winter. Once vertically equilibrated in the Gulf of Aden, the shallowest RSOW was strongly influenced by mesoscale eddies that swept it farther into the gulf. The deeper RSOW was initially more confined by the walls of the Tadjura Rift, but eventually it escaped from the rift and was advected mainly southward along the continental slope. There was no evidence of a continuous boundary undercurrent of RSOW similar to the Mediterranean Undercurrent in the Gulf of Cadiz. This is explained by considering 1) the variability in outflow transport and 2) several different criteria for separation of a jet at a sharp corner, which indicate that the outflow currents should separate from the boundary where they are injected into the gulf.

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Martin, Paige E., Brian K. Arbic, and Andrew McC Hogg. "Drivers of Atmospheric and Oceanic Surface Temperature Variance: A Frequency Domain Approach." Journal of Climate 34, no. 10 (May 2021): 3975–90. http://dx.doi.org/10.1175/jcli-d-20-0557.1.

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AbstractOcean–atmosphere coupling modifies the variability of Earth’s climate over a wide range of time scales. However, attribution of the processes that generate this variability remains an outstanding problem. In this article, air–sea coupling is investigated in an eddy-resolving, medium-complexity, idealized ocean–atmosphere model. The model is run in three configurations: fully coupled, partially coupled (where the effect of the ocean geostrophic velocity on the sea surface temperature field is minimal), and atmosphere-only. A surface boundary layer temperature variance budget analysis computed in the frequency domain is shown to be a powerful tool for studying air–sea interactions, as it differentiates the relative contributions to the variability in the temperature field from each process across a range of time scales (from daily to multidecadal). This method compares terms in the ocean and atmosphere across the different model configurations to infer the underlying mechanisms driving temperature variability. Horizontal advection plays a dominant role in driving temperature variance in both the ocean and the atmosphere, particularly at time scales shorter than annual. At longer time scales, the temperature variance is dominated by strong coupling between atmosphere and ocean. Furthermore, the Ekman transport contribution to the ocean’s horizontal advection is found to underlie the low-frequency behavior in the atmosphere. The ocean geostrophic eddy field is an important driver of ocean variability across all frequencies and is reflected in the atmospheric variability in the western boundary current separation region at longer time scales.

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Cai, Zhongya, and Jianping Gan. "Formation and Dynamics of a Long-Lived Eddy Train in the South China Sea: A Modeling Study." Journal of Physical Oceanography 47, no. 11 (November 2017): 2793–810. http://dx.doi.org/10.1175/jpo-d-17-0002.1.

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AbstractA process-oriented numerical modeling study was conducted to investigate the formation and underlying forcing of an anticyclonic eddy train observed in the northern South China Sea. Observations showed that long-lived anticyclonic eddies formed an eddy train along an eastward separated jet across the northern South China Sea in summer. The eddy train plays a critical role in regulating ocean circulation in the region. Forced by the southwesterly monsoon and prevailing dipole wind stress curl in the summer, the northward coastal jet separates from the west boundary of the South China Sea basin and overshoots northeastward into the basin. The anticyclonic recirculation of the separated jet forms the first anticyclonic eddy in the eddy train. The jet meanders downstream with a strong negative shear vorticity that forms a second and a third anticyclonic eddy along the jet’s path. These three eddies form the eddy train. These eddies weaken gradually with depth from surface, but they can extend to approximately 500 m deep. The inherent stratification in the region regulates the three-dimensional scale of the anticyclonic eddies and constrains their intensity vertical extension by weakening the geostrophic balance within these eddies. Analyses of the vorticity balance indicate that the eddy train’s negative vorticity originates from the beta effect of northward western boundary current and from the subsequent downstream vorticity advection in the jet. The jet separation is a necessary condition for the formation of the eddy train, and the enhanced stratification, increased summer wind stress, and associated negative wind stress curl are favorable conditions for the formation of the anticyclonic eddies.

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da Silveira, Ilson C. A., Glenn R. Flierl, and Wendell S. Brown. "Dynamics of Separating Western Boundary Currents." Journal of Physical Oceanography 29, no. 2 (February 1999): 119–44. http://dx.doi.org/10.1175/1520-0485(1999)029<0119:doswbc>2.0.co;2.

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Zeiden, Kristin L., Daniel L. Rudnick, and Jennifer A. MacKinnon. "Glider Observations of a Mesoscale Oceanic Island Wake." Journal of Physical Oceanography 49, no. 9 (September 2019): 2217–35. http://dx.doi.org/10.1175/jpo-d-18-0233.1.

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AbstractIn this study, a 2-yr time series of velocity profiles to 1000 m from meridional glider surveys is used to characterize the wake in the lee of a large island in the western tropical North Pacific Ocean, Palau. Surveys were completed along sections to the east and west of the island to capture both upstream and downstream conditions. Objectively mapped in time and space, mean sections of velocity show the incident westward North Equatorial Current accelerating around the island of Palau, increasing from 0.1 to 0.2 m s−1 at the surface. Downstream of the island, elevated velocity variability and return flow in the lee are indicative of boundary layer separation. Isolating for periods of depth-average westward flow reveals a length scale in the wake that reflects local details of the topography. Eastward flow is shown to produce an asymmetric wake. Depth-average velocity time series indicate that energetic events (on time scales from weeks to months) are prevalent. These events are associated with mean vorticity values in the wake up to 0.3f near the surface and with instantaneous values that can exceed f (the local Coriolis frequency) during periods of sustained, anomalously strong westward flow. Thus, ageostrophic effects become important to first order.

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32

Takatama, Kohei, Shoshiro Minobe, Masaru Inatsu, and R. Justin Small. "Diagnostics for Near-Surface Wind Response to the Gulf Stream in a Regional Atmospheric Model*." Journal of Climate 28, no. 1 (December 31, 2014): 238–55. http://dx.doi.org/10.1175/jcli-d-13-00668.1.

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Abstract The mechanisms acting on near-surface winds over the Gulf Stream are diagnosed using 5-yr outputs of a regional atmospheric model. The diagnostics for the surface-layer momentum vector, its curl, and its convergence are developed with a clear separation of pressure adjustment from downward momentum inputs from aloft in the surface-layer system. The results suggest that the downward momentum mixing mechanism plays a dominant role in contributing to the annual-mean climatological momentum curl, whereas the pressure adjustment mechanism plays a minor role. In contrast, the wind convergence is mainly due to the pressure adjustment mechanism. This can be explained by the orientation of background wind to the sea surface temperature front. The diagnostics also explain the relatively strong seasonal variation in surface-layer momentum convergence and the small seasonal variation in curl. Finally, the surface-layer response to other western boundary currents is examined using a reanalysis dataset.

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Wolfram, Phillip J., Todd D. Ringler, Mathew E. Maltrud, Douglas W. Jacobsen, and Mark R. Petersen. "Diagnosing Isopycnal Diffusivity in an Eddying, Idealized Midlatitude Ocean Basin via Lagrangian, in Situ, Global, High-Performance Particle Tracking (LIGHT)." Journal of Physical Oceanography 45, no. 8 (August 2015): 2114–33. http://dx.doi.org/10.1175/jpo-d-14-0260.1.

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AbstractIsopycnal diffusivity due to stirring by mesoscale eddies in an idealized, wind-forced, eddying, midlatitude ocean basin is computed using Lagrangian, in Situ, Global, High-Performance Particle Tracking (LIGHT). Simulation is performed via LIGHT within the Model for Prediction across Scales Ocean (MPAS-O). Simulations are performed at 4-, 8-, 16-, and 32-km resolution, where the first Rossby radius of deformation (RRD) is approximately 30 km. Scalar and tensor diffusivities are estimated at each resolution based on 30 ensemble members using particle cluster statistics. Each ensemble member is composed of 303 665 particles distributed across five potential density surfaces. Diffusivity dependence upon model resolution, velocity spatial scale, and buoyancy surface is quantified and compared with mixing length theory. The spatial structure of diffusivity ranges over approximately two orders of magnitude with values of O(105) m2 s−1 in the region of western boundary current separation to O(103) m2 s−1 in the eastern region of the basin. Dominant mixing occurs at scales twice the size of the first RRD. Model resolution at scales finer than the RRD is necessary to obtain sufficient model fidelity at scales between one and four RRD to accurately represent mixing. Mixing length scaling with eddy kinetic energy and the Lagrangian time scale yield mixing efficiencies that typically range between 0.4 and 0.8. A reduced mixing length in the eastern region of the domain relative to the west suggests there are different mixing regimes outside the baroclinic jet region.

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GREHAN, JOHN R., and CARLOS G. C. MIELKE. "Evolutionary biogeography and tectonic history of the ghost moth families Hepialidae, Mnesarchaeidae, and Palaeosetidae in the Southwest Pacific (Lepidoptera: Exoporia)." Zootaxa 4415, no. 2 (April 30, 2018): 243. http://dx.doi.org/10.11646/zootaxa.4415.2.2.

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The biogeographic history of Exoporia (Lepidoptera) in the Southwest Pacific is reconstructed for genera and species that show distributional boundaries corresponding to tectonic structures in the region. Correlations with tectonic formations of Mesozoic origin such as the Whitsunday Volcanic Province and Otway-Bass-Gippsland Basin system in Australia, the Vitiaz Fracture Zone in northern Melanesia, and the Western Province-Eastern Province boundary, Waitaki Fault Zone, and Waihemo Fault Zone of New Zealand are presented as evidence of an East Gondwana origin for genera and species before the geological separation of Australia and New Zealand. The correlated boundaries also suggest that many extant species retain at least parts of their original East Gondwana distribution ranges. The presence of Exoporia on the northern Melanesian Arc, New Caledonia, and New Zealand is attributed to the tectonic isolation of these areas when East Gondwana expanded into the Pacific following retreat of the Pacific Plate subduction zone. Local endemism of Mnesarchaeidae in New Zealand is interpreted as the result of an original vicariance from a widespread ancestor (‘Exoporia’) resulting in two allopatric descendants —a narrowly distributed Mnesarchoidea and a widely distributed Hepialoidea. The current overlap of these two groups in New Zealand is explained as the result of subsequent range expansion by the Hepialoidea prior to geological fragmentation of East Gondwana. The potential impact of Cretaceous geography on modern distributions is also considered for Exoporia in southern Africa and northern America. Along with lateral displacement of Exoporia, tectonic processes also contributed to the origin of high elevation endemics through a process of passive tectonic uplift.

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35

Berloff, P., W. Dewar, S. Kravtsov, and J. McWilliams. "Ocean Eddy Dynamics in a Coupled Ocean–Atmosphere Model*." Journal of Physical Oceanography 37, no. 5 (May 1, 2007): 1103–21. http://dx.doi.org/10.1175/jpo3041.1.

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Abstract The role of mesoscale oceanic eddies is analyzed in a quasigeostrophic coupled ocean–atmosphere model operating at a large Reynolds number. The model dynamics are characterized by decadal variability that involves nonlinear adjustment of the ocean to coherent north–south shifts of the atmosphere. The oceanic eddy effects are diagnosed by the dynamical decomposition method adapted for nonstationary external forcing. The main effects of the eddies are an enhancement of the oceanic eastward jet separating the subpolar and subtropical gyres and a weakening of the gyres. The flow-enhancing effect is due to nonlinear rectification driven by fluctuations of the eddy forcing. This is a nonlocal process involving generation of the eddies by the flow instabilities in the western boundary current and the upstream part of the eastward jet. The eddies are advected by the mean current to the east, where they backscatter into the rectified enhancement of the eastward jet. The gyre-weakening effect, which is due to the time-mean buoyancy component of the eddy forcing, is a result of the baroclinic instability of the westward return currents. The diagnosed eddy forcing is parameterized in a non-eddy-resolving ocean model, as a nonstationary random process, in which the corresponding parameters are derived from the control coupled simulation. The key parameter of the random process—its variance—is related to the large-scale flow baroclinicity index. It is shown that the coupled model with the non-eddy-resolving ocean component and the parameterized eddies correctly simulates climatology and low-frequency variability of the control eddy-resolving coupled solution.

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36

Li, Yiwen, Hailong Liu, Mengrong Ding, Pengfei Lin, Zipeng Yu, Yongqiang Yu, Yao Meng, et al. "Eddy-resolving Simulation of CAS-LICOM3 for Phase 2 of the Ocean Model Intercomparison Project." Advances in Atmospheric Sciences 37, no. 10 (August 25, 2020): 1067–80. http://dx.doi.org/10.1007/s00376-020-0057-z.

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Abstract A 61-year (1958–2018) global eddy-resolving dataset for phase 2 of the Ocean Model Intercomparison Project has been produced by the version 3 of Chinese Academy of Science, the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics/Institute of Atmospheric Physics (LASG/IAP) Climate system Ocean Model (CAS-LICOM3). The monthly and a part of the surface daily data in this study can be accessed on the Earth System Grid Federation (ESGF) node. Besides the details of the model and experiments, the evolutions and spatial patterns of large-scale and mesoscale features are also presented. The mesoscale features are reproduced well in the high-resolution simulation, as the mesoscale activities can contribute up to 50% of the total SST variability in eddy-rich regions. Also, the large-scale circulations are remarkably improved compared with the low-resolution simulation, such as the climatological annual mean SST (the RMSE is reduced from 0.59°C to 0.47°C, globally) and the evolution of Atlantic Meridional Overturning Circulation. The preliminary evaluation also indicates that there are systematic biases in the salinity, the separation location of the western boundary currents, and the magnitude of eddy kinetic energy. All these biases are worthy of further investigation.

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37

Kiss, Andrew E. "Dynamics of separating western boundary currents in ocean models." IOP Conference Series: Earth and Environmental Science 11 (August 1, 2010): 012034. http://dx.doi.org/10.1088/1755-1315/11/1/012034.

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38

Jaiswal, A. K., A. Satheesh T, K. Pandey, P. Kumar, and S. Saran. "GEOSPATIAL MULTI-CRITERIA DECISION BASED SITE SUITABILITY ANALYSIS FOR SOLID WASTE DISPOSAL USING TOPSIS ALGORITHM." ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-5 (November 15, 2018): 431–38. http://dx.doi.org/10.5194/isprs-annals-iv-5-431-2018.

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<p><strong>Abstract.</strong> The problem of Urban Municipal solid waste disposal is a challenging task faced by civic bodies and planning authorities in almost all the cities of rapidly developing countries like India. A similar situation is being faced by Dehradun, the capital, and the fastest growing city of Uttarakhand, India. In the current study, an attempt has been made to find out the suitable sites for waste disposal in the area around Dehradun city using Geospatial Multi-criteria Decision Analysis (MCDA) techniques from remote sensing data. Two different decision rules of MCDA are used, namely, Analytical Hierarchical Process based Weighted Linear Combination (AHP – WLC) and Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS). WLC has been used previously for similar studies for its ease and simplicity to apply in raster format but TOPSIS has an advantage over WLC, it orders a set of alternatives on the basis of their separation from the ideal point. It defines the best alternative as the one that is simultaneously closest to the ideal alternative and farthest from the negative ideal point. Raster-based suitability analysis has been done and the results obtained by the two methods are compared. Identical results with minor differences identifying best suitable sites outside the eastern boundary of the city where the existing dumping site is located are obtained. Also, new potential sites are identified in the western part of the city which faces the problem of waste disposal more acutely because of expansion of the city in that direction.</p>

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39

Cessi, Paola. "The Effect of Northern Hemisphere Winds on the Meridional Overturning Circulation and Stratification." Journal of Physical Oceanography 48, no. 10 (October 2018): 2495–506. http://dx.doi.org/10.1175/jpo-d-18-0085.1.

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AbstractThe current paradigm for the meridional overturning cell and the associated middepth stratification is that the wind stress in the subpolar region of the Southern Ocean drives a northward Ekman flow, which, together with the global diapycnal mixing across the lower boundary of the middepth waters, feeds the upper branch of the interhemispheric overturning. The resulting mass transport proceeds to the Northern Hemisphere of the North Atlantic, where it sinks, to be eventually returned to the Southern Ocean at depth. Seemingly, the wind stress in the Atlantic basin plays no role. This asymmetry occurs because the Ekman transport in the Atlantic Ocean is assumed to return geostrophically at depths much shallower than those occupied by the interhemispheric overturning. However, this vertical separation fails in the North Atlantic subpolar gyre region. Using a conceptual model and an ocean general circulation model in an idealized geometry, we show that the westerly wind stress in the northern part of the Atlantic provides two opposing effects. Mechanically, the return of the Ekman transport in the North Atlantic opposes sinking in this region, reducing the total overturning and deepening the middepth stratification; thermodynamically, the subpolar gyre advects salt poleward, promoting Northern Hemisphere sinking. Depending on which mechanism prevails, increased westerly winds in the Northern Hemisphere can reduce or augment the overturning.

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40

Marshall, David P., and Claire E. Tansley. "An Implicit Formula for Boundary Current Separation." Journal of Physical Oceanography 31, no. 6 (June 2001): 1633–38. http://dx.doi.org/10.1175/1520-0485(2001)031<1633:aiffbc>2.0.co;2.

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41

Carstens, Torkild. "Geostrophic boundary current separation from a coast." Journal of Geophysical Research 92, no. C5 (1987): 5342. http://dx.doi.org/10.1029/jc092ic05p05342.

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42

Ribbe, Joachim, and Daniel Brieva. "A western boundary current eddy characterisation study." Estuarine, Coastal and Shelf Science 183 (December 2016): 203–12. http://dx.doi.org/10.1016/j.ecss.2016.10.036.

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43

Berloff, Pavel S., and James C. McWilliams. "Quasigeostrophic Dynamics of the Western Boundary Current." Journal of Physical Oceanography 29, no. 10 (October 1999): 2607–34. http://dx.doi.org/10.1175/1520-0485(1999)029<2607:qdotwb>2.0.co;2.

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44

Ribbe, Joachim, Liv Toaspern, Jörg-Olaf Wolff, and Mochamad Furqon Azis Ismail. "Frontal eddies along a western boundary current." Continental Shelf Research 165 (August 2018): 51–59. http://dx.doi.org/10.1016/j.csr.2018.06.007.

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45

Pickart, Robert S., and D. Randolph Watts. "Deep Western Boundary Current variability at Cape Hatteras." Journal of Marine Research 48, no. 4 (November 1, 1990): 765–91. http://dx.doi.org/10.1357/002224090784988674.

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46

Pickart, Robert S., and Rui Xin Huang. "Structure of an inertial deep western boundary current." Journal of Marine Research 53, no. 5 (September 1, 1995): 739–70. http://dx.doi.org/10.1357/0022240953213007.

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47

Katsumata, Katsurou. "Stability of a western boundary current with curvature." Geophysical & Astrophysical Fluid Dynamics 87, no. 1-2 (March 1998): 51–79. http://dx.doi.org/10.1080/03091929808208994.

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48

Campos, Edmo J. D., and Donald B. Olson. "Stationary Rossby Waves in Western Boundary Current Extensions." Journal of Physical Oceanography 21, no. 8 (August 1991): 1202–24. http://dx.doi.org/10.1175/1520-0485(1991)021<1202:srwiwb>2.0.co;2.

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49

Page, Michael A., and E. R. Johnson. "Nonlinear western boundary current flow near a corner." Dynamics of Atmospheres and Oceans 15, no. 6 (July 1991): 477–504. http://dx.doi.org/10.1016/0377-0265(91)90001-v.

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50

Johns, William E., David M. Fratantoni, and Rainer J. Zantopp. "Deep western boundary current variability off northeastern Brazil." Deep Sea Research Part I: Oceanographic Research Papers 40, no. 2 (February 1993): 293–310. http://dx.doi.org/10.1016/0967-0637(93)90005-n.

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Journal articles on the topic 'Western boundary current separation'

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