ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Eddies
  • American Meteorological Society  (60)
  • Blackwell Publishing Ltd
  • Molecular Diversity Preservation International (MDPI)
  • Springer Nature
Collection
Keywords
Years
  • 11
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2011. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 41 (2011): 2168–2186, doi:10.1175/JPO-D-11-08.1.
    Description: This paper studies the interaction of an Antarctic Circumpolar Current (ACC)–like wind-driven channel flow with a continental slope and a flat-bottomed bay-shaped shelf near the channel’s southern boundary. Interaction between the model ACC and the topography in the second layer induces local changes of the potential vorticity (PV) flux, which further causes the formation of a first-layer PV front near the base of the topography. Located between the ACC and the first-layer slope, the newly formed PV front is constantly perturbed by the ACC and in turn forces the first-layer slope with its own variability in an intermittent but persistent way. The volume transport of the slope water across the first-layer slope edge is mostly directly driven by eddies and meanders of the new front, and its magnitude is similar to the maximum Ekman transport in the channel. Near the bay’s opening, the effect of the topographic waves, excited by offshore variability, dominates the cross-isobath exchange and induces a mean clockwise shelf circulation. The waves’ propagation is only toward the west and tends to be blocked by the bay’s western boundary in the narrow-shelf region. The ensuing wave–coast interaction amplifies the wave amplitude and the cross-shelf transport. Because the interaction only occurs near the western boundary, the shelf water in the west of the bay is more readily carried offshore than that in the east and the mean shelf circulation is also intensified along the bay’s western boundary.
    Description: Y. Zhang acknowledges the support of the MIT-WHOI Joint Program in Physical Oceanography and NSF OCE-9901654 and OCE- 0451086. J. Pedlosky acknowledges the support of NSF OCE-9901654 and OCE-0451086.
    Keywords: Baroclinic flows ; Eddies ; Fronts ; Mass fluxes/transport ; Mesoscale processes ; Topographic effects
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2012. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 42 (2012): 2206–2228, doi:10.1175/JPO-D-11-0191.1.
    Description: This study investigates the anisotropic properties of the eddy-induced material transport in the near-surface North Atlantic from two independent datasets, one simulated from the sea surface height altimetry and one derived from real-ocean surface drifters, and systematically examines the interactions between the mean- and eddy-induced material transport in the region. The Lagrangian particle dispersion, which is widely used to characterize the eddy-induced tracer fluxes, is quantified by constructing the “spreading ellipses.” The analysis consistently demonstrates that this dispersion is spatially inhomogeneous and strongly anisotropic. The spreading is larger and more anisotropic in the subtropical than in the subpolar gyre, and the largest ellipses occur in the Gulf Stream vicinity. Even at times longer than half a year, the spreading exhibits significant nondiffusive behavior in some parts of the domain. The eddies in this study are defined as deviations from the long-term time-mean. The contributions from the climatological annual cycle, interannual, and subannual (shorter than one year) variability are investigated, and the latter is shown to have the strongest effect on the anisotropy of particle spreading. The influence of the mean advection on the eddy-induced particle spreading is investigated using the “eddy-following-full-trajectories” technique and is found to be significant. The role of the Ekman advection is, however, secondary. The pronounced anisotropy of particle dispersion is expected to have important implications for distributing oceanic tracers, and for parameterizing eddy-induced tracer transfer in non-eddy-resolving models.
    Description: IR was supported by Grant NSF-OCE-0725796. IK would like to acknowledge support by the National Science foundation Grant OCE-0842834.
    Description: 2013-06-01
    Keywords: North Atlantic Ocean ; Diffusion ; Dispersion ; Eddies ; Lagrangian circulation/transport ; Trajectories
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2013. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 43 (2013): 905–919, doi:10.1175/JPO-D-12-0150.1.
    Description: Interactions between vortices and a shelfbreak current are investigated, with particular attention to the exchange of waters between the continental shelf and slope. The nonlinear, three-dimensional interaction between an anticyclonic vortex and the shelfbreak current is studied in the laboratory while varying the ratio ε of the maximum azimuthal velocity in the vortex to the maximum alongshelf velocity in the shelfbreak current. Strong interactions between the shelfbreak current and the vortex are observed when ε 〉 1; weak interactions are found when ε 〈 1. When the anticyclonic vortex comes in contact with the shelfbreak front during a strong interaction, a streamer of shelf water is drawn offshore and wraps anticyclonically around the vortex. Measurements of the offshore transport and identification of the particle trajectories in the shelfbreak current drawn offshore from the vortex allow quantification of the fraction of the shelfbreak current that is deflected onto the slope; this fraction increases for increasing values of ε. Experimental results in the laboratory are strikingly similar to results obtained from observations in the Middle Atlantic Bight (MAB); after proper scaling, measurements of offshore transport and offshore displacement of shelf water for vortices in the MAB that span a range of values of ε agree well with laboratory predictions.
    Description: Laboratory work was supported by the National Science Foundation through Grant OCE- 0081756. Glider observations in March–April 2006 were supported by the National Science Foundation through Grant OCE-0220769. Glider observations in July– October 2007 were supported by a grant from Raytheon. RET was supported by the Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution, with funding provided by the Cooperative Institute for the North Atlantic Region. The REMUS observations were funded by the Office of Naval Research. GGG was supported by the National Science Foundation through Grant OCE-1129125 for analysis and writing.
    Description: 2013-11-01
    Keywords: Continental shelf/slope ; Eddies ; Fronts ; Transport ; Laboratory/physical models
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2013. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 26 (2013): 9839–9859, doi:10.1175/JCLI-D-12-00647.1.
    Description: Spatial and temporal covariability between the atmospheric transient eddy heat fluxes (i.e., υ′T′ and υ′q′) in the Northern Hemisphere winter (January–March) and the paths of the Gulf Stream (GS), Kuroshio Extension (KE), and Oyashio Extension (OE) are examined based on an atmospheric reanalyses and ocean observations for 1979–2009. For the climatological winter mean, the northward heat fluxes by the synoptic (2–8 days) transient eddies exhibit canonical storm tracks with their maxima collocated with the GS and KE/OE. The intraseasonal (8 days–3 months) counterpart, while having overall similar amplitude, shows a spatial pattern with more localized maxima near the major orography and blocking regions. Lateral heat flux divergence by transient eddies as the sum of the two frequency bands exhibits very close coupling with the exact locations of the ocean fronts. Linear regression is used to examine the lead–lag relationship between interannual changes in the northward heat fluxes by the transient eddies and the meridional changes in the paths of the GS, KE, and OE, respectively. One to three years prior to the northward shifts of each ocean front, the atmospheric storm tracks shift northward and intensify, which is consistent with wind-driven changes of the ocean. Following the northward shifts of the ocean fronts, the synoptic storm tracks weaken in all three cases. The zonally integrated northward heat transport by the synoptic transient eddies increases by ~5% of its maximum mean value prior to the northward shift of each ocean front and decreases to a similar amplitude afterward.
    Description: Support from the National Aeronautics and Space Administration (NASA) Physical Oceanography Program (NNX09AF35G to TJ and Y-OK) and the Department of Energy (DOE) Climate and Environmental Sciences Division (DE-SC0007052 to Y-OK) is gratefully acknowledged.
    Description: 2014-06-15
    Keywords: Atmosphere-ocean interaction ; Eddies ; Energy transport ; Storm tracks ; Heat budgets/fluxes
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    facet.materialart.
    Unknown
    American Meteorological Society
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2015. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 45 (2015): 606–612, doi:10.1175/JPO-D-14-0221.1.
    Description: Mesoscale intrathermocline lenses are observed throughout the World Ocean and are commonly attributed to water mass anomalies advected from a distant origin. An alternative mechanism of local generation is offered herein, in which eddy–wind interaction can create lens-shaped disturbances in the thermocline. Numerical simulations illustrate how eddy–wind-driven upwelling in anticyclones can yield a convex lens reminiscent of a mode water eddy, whereas eddy–wind-driven downwelling in cyclones produces a concave lens that thins the mode water layer (a cyclonic “thinny”). Such transformations should be observable with long-term time series in the interiors of mesoscale eddies.
    Description: Support of this research by the National Science Foundation and National Aeronautics and Space Administration is gratefully acknowledged.
    Description: 2015-08-01
    Keywords: Circulation/ Dynamics ; Eddies ; Ekman pumping/transport ; Mesoscale processes ; Models and modeling ; Ocean models ; Primitive equations model
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    facet.materialart.
    Unknown
    American Meteorological Society
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2015. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 45 (2015): 2820–2835, doi:10.1175/JPO-D-15-0101.1.
    Description: The response of a convective ocean basin to variations in atmospheric temperature is explored using numerical models and theory. The results indicate that the general behavior depends strongly on the frequency at which the atmosphere changes relative to the local response time to air–sea heat flux. For high-frequency forcing, the convective region in the basin interior is essentially one-dimensional and responds to the integrated local surface heat flux anomalies. For low-frequency forcing, eddy fluxes from the boundary current into the basin interior become important and act to suppress variability forced by the atmosphere. A theory is developed to quantify this time-dependent response and its influence on various oceanic quantities. The amplitude and phase of the temperature and salinity of the convective water mass, the meridional overturning circulation, the meridional heat flux, and the air–sea heat flux predicted by the theory compare well with that diagnosed from a series of numerical model calculations in both strongly eddying and weakly eddying regimes. Linearized analytic solutions provide direct estimates of each of these quantities and demonstrate their dependence on the nondimensional numbers that characterize the domain and atmospheric forcing. These results highlight the importance of mesoscale eddies in modulating the mean and time-dependent ocean response to atmospheric variability and provide a dynamical framework with which to connect ocean observations with changes in the atmosphere and surface heat flux.
    Description: This study was supported by the National Science Foundation under Grant OCE-1232389.
    Description: 2016-05-01
    Keywords: Circulation/ Dynamics ; Atmosphere-ocean interaction ; Deep convection ; Eddies ; Meridional overturning circulation
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2016. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 46 (2016): 2645-2662, doi:10.1175/JPO-D-15-0191.1.
    Description: The occurrence, drivers, and implications of small-scale O(2–5) km diameter coherent vortices, referred to as submesoscale eddies, over the inner shelf south of Martha’s Vineyard, Massachusetts, are examined using high-frequency (HF), radar-based, high-resolution (400 m) observations of surface currents. Within the 300 km2 study area, eddies occurred at rates of 1 and 4 day−1 in winter and summer, respectively. Most were less than 5 h in duration, smaller than 4 km in diameter, and rotated less than once over their lifespan; 60% of the eddies formed along the eastern edge of study area, adjacent to Wasque Shoal, and moved westward into the interior, often with relative vorticity greater than f. Eddy generation was linked to vortex stretching on the ebb and flood tide as well as the interaction of the spatially variable tide and the wind-driven currents; however, these features had complex patterns of surface divergence and stretching. Eddies located away from Wasque Shoal were related to the movement of wind-driven surface currents, as wind direction controlled where eddies formed as well as density effects. Using an analysis of particles advected within the radar-based surface currents, the observed eddies were found to be generally leaky, losing 60%–80% of particles over their lifespan, but still more retentive than the background flow. As a result, the combined translation and rotational effects of the observed eddies were an important source of lateral exchange for surface waters over the inner shelf.
    Description: The HF radar data utilized here were obtained using internal funding from the Woods Hole Oceanographic Institution. The analysis was supported by NSF OCE Grant 1332646.
    Description: 2017-02-19
    Keywords: Geographic location/entity ; Continental shelf/slope ; Circulation/ Dynamics ; Currents ; Eddies ; Observational techniques and algorithms ; Radars/Radar observations
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2017. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 47 (2017): 1291-1305, doi:10.1175/JPO-D-16-0160.1.
    Description: Along-stream variations in the dynamics of the Antarctic Circumpolar Current (ACC) impact heat and tracer transport, regulate interbasin exchange, and influence closure of the overturning circulation. Topography is primarily responsible for generating deviations from zonal-mean properties, mainly through standing meanders associated with regions of high eddy kinetic energy. Here, an idealized channel model is used to explore the spatial distribution of energy exchange and its relationship to eddy geometry, as characterized by both eddy momentum and eddy buoyancy fluxes. Variations in energy exchange properties occur not only between standing meander and quasi-zonal jet regions, but throughout the meander itself. Both barotropic and baroclinic stability properties, as well as the magnitude of energy exchange terms, undergo abrupt changes along the path of the ACC. These transitions are captured by diagnosing eddy fluxes of energy and by adopting the eddy geometry framework. The latter, typically applied to barotropic stability properties, is applied here in the depth–along-stream plane to include information about both barotropic and baroclinic stability properties of the flow. These simulations reveal that eddy momentum fluxes, and thus barotropic instability, play a leading role in the energy budget within a standing meander. This result suggests that baroclinic instability alone cannot capture the dynamics of ACC standing meanders, a challenge for models where eddy fluxes are parameterized.
    Description: The authors all acknowledge support from NSF OCE-1235488. MKY also acknowledges support from the AMS Graduate Student Fellowship.
    Description: 2017-10-12
    Keywords: Southern Ocean ; Channel flows ; Stability ; Topographic effects ; Eddies ; Mesoscale models
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2009. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 39 (2009): 1551-1573, doi:10.1175/2008JPO4152.1.
    Description: A conceptually simple model is presented for predicting the amplitude and periodicity of eddies generated by a steady poleward outflow in a 1½-layer β-plane formulation. The prediction model is rooted in linear quasigeostrophic dynamics but is capable of predicting the amplitude of the β plume generated by outflows in the nonlinear range. Oscillations in the plume amplitude are seen to represent a near-zero group velocity response to an adjustment process that can be traced back to linear dynamics. When the plume-amplitude oscillations become large enough so that the coherent β plume is replaced by a robust eddy field, the eddy amplitude is still constrained by the plume-amplitude prediction model. The eddy periodicity remains close to that of the predictable, near-zero group-velocity linear oscillations. Striking similarities between the patterns of variability in the model and observations south of Indonesia’s Lombok Strait suggest that the processes investigated in this study may play an important role in the generation of the observed eddy field of the Indo-Australian Basin.
    Description: This work was completed at the Woods Hole Oceanographic Institution while TS Durland was supported by the Ocean and Climate Change Institute. MA Spall was supported by NSF Grant OCE-0423975 and J Pedlosky by NSF Grant OCE-0451086. TS Durland acknowledges additional report preparation support from NASA Grant NNG05GN98G.
    Keywords: Eddies ; Intraseasonal variability ; Nonlinear models ; Shallow-water equations ; Plumes
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2022-05-25
    Description: Author Posting. © American Meteorological Society, 2014. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 44 (2014): 229–245, doi:10.1175/JPO-D-12-0218.1.
    Description: Data from a mooring deployed at the edge of the East Greenland shelf south of Denmark Strait from September 2007 to October 2008 are analyzed to investigate the processes by which dense water is transferred off the shelf. It is found that water denser than 27.7 kg m−3—as dense as water previously attributed to the adjacent East Greenland Spill Jet—resides near the bottom of the shelf for most of the year with no discernible seasonality. The mean velocity in the central part of the water column is directed along the isobaths, while the deep flow is bottom intensified and veers offshore. Two mechanisms for driving dense spilling events are investigated, one due to offshore forcing and the other associated with wind forcing. Denmark Strait cyclones propagating southward along the continental slope are shown to drive off-shelf flow at their leading edges and are responsible for much of the triggering of individual spilling events. Northerly barrier winds also force spilling. Local winds generate an Ekman downwelling cell. Nonlocal winds also excite spilling, which is hypothesized to be the result of southward-propagating coastally trapped waves, although definitive confirmation is still required. The combined effect of the eddies and barrier winds results in the strongest spilling events, while in the absence of winds a train of eddies causes enhanced spilling.
    Description: The authors wish to thank Paula Fratantoni, Frank Bahr, and Dan Torres for processing the mooring data. The mooring array was capably deployed by the crew of the R/V Arni Fridriksson and recovered by the crew of the R/V Knorr. We thank Hedinn Valdimarsson for his assistance in the field work. Ken Brink provided valuable insights regarding the dynamics of shelf waves. Funding for the study was provided by National Science Foundation Grant OCE-0722694, the Arctic Research Initiative of the Woods Hole Oceanographic Institution. We also wish to thank the Natural Environment Research Council for Ph.D. studentship funding, and the University of East Anglia’s Roberts Fund and Royal Meteorological Society for supporting travel for collaboration.
    Description: 2014-07-01
    Keywords: Geographic location/entity ; Continental shelf/slope ; Circulation/ Dynamics ; Meridional overturning circulation ; Upwelling/downwelling ; Atm/Ocean Structure/ Phenomena ; Eddies ; Extreme events ; Physical Meteorology and Climatology ; Air-sea interaction
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...