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  • 1
    Electronic Resource
    Electronic Resource
    Some hydrodynamic problems for a nepheloid zone (1966)
    Springer
    Pure and applied geophysics 63 (1966), S. 179-195 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary A layer of a few hundred meters thickness with suspended matter (a nepheloid zone) was discovered byEwing andThorndike [4]3) near the bottom on the continental slope of the North Atlantic. A downward pressure gradient is produced in this layer due to increment of water density with suspensoid. When only the Coriolis force balances with this pressure gradient, a bottom nepheloid current flows southwestward parallel to the depth contours with a velocity of about 10 (cm/sec) for a slope of one degree. The pressure gradient for fluid with locally variable density above a sloping bottom is treated and an extra term due to density gradient along the slope is derived. The vertical profiles of the nepheloid current with an effect on the vertical eddy viscosity are computed. Two kinds of vertical distributions of eddy viscosity are determined from the observed nepheloid distributions and used in the calculations: constant but different values at two layers and those increasing with height. The effect of the change of density along the bottom is treated by introducing dimensionless variables. Rossby number of the nepheloid current becomes about 10−2 indicating inertia terms to be negligible. Rossby number of turbidity currents ranges from 2 (in a decaying area) to 5 (developing area), suggesting that inertia terms are more important than Coriolis terms. The trajectories of turbidity currents are computed from motion of a mass of mud under the Coriolis force and friction, and the results are applied to those inferred byHand andEmery [6] in the San Diego Through off California.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00875168
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  • 2
    Electronic Resource
    Electronic Resource
    Occurrence of temperature inversions in the upper layer of the ocean (1967)
    Springer
    Pure and applied geophysics 67 (1967), S. 143-155 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary Bathythermograms just off the northern edge of the Gulf Stream often show temperature inversions, while those in the Gulf Stream and the Sargasso Sea do not show such features. A similar situation was found in the Kuroshio area. TheT-S curve obtained off Cape Hatteras with a bathysalinograph and a bathythermograph indicates that the temperature inversions correspond to high salinity and less stable density stratification. Sequential surface temperature charts suggest that the inversions may be caused by sinking of the warm and saline Gulf Stream water. When such water is driven into the slope water region, it is cooled by mixing or heat transfer to the atmosphere, but retains its high salinity and sinks. A simple mathematical model is developed based on an assumption that an isolated water mass is enclosed in a parcel with a flexible and permeable membrane. The initial density inside the parcel is different from the one outside and the water mixes with the surrounding water. When it is assumed that mixing of temperature occurs faster than that of salinity, the isolated Gulf Stream water sinks to an equilibrium depth, causing temperature peaks and inversions in the subsurface layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00880572
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  • 3
    Electronic Resource
    Electronic Resource
    On formation of the intermediate water in the Northern Pacific Ocean (1962)
    Springer
    Pure and applied geophysics 51 (1962), S. 108-119 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary Meridional cross sections of temperature, salinity and oxygen of the North Pacific Ocean are prepared to show location of the intermediate water, which is formed at the polar front and spreads on constantsigma-t surfaces. Geostrophic flow in a meridional plane is obtained by dynamic calculation. Friction-driven meridional circulation is determined from the zonally averaged density distribution. The latter flow seems to be more appropriate for explanation of mechanism of spread of the water.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01992653
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  • 4
    Electronic Resource
    Electronic Resource
    Power spectra of temperature and salinity fluctuations in the slope water off Cape Hatteras (1972)
    Springer
    Pure and applied geophysics 96 (1972), S. 205-216 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary Eleven STD stations by lowering and raising the sensor were occupied about 170 n. miles northeast of Cape Hatteras in June, 1968. The stations were located in the slope water region covered by the upper warm water from the Gulf Stream. Power spectra of temperature and salinity fluctuations at 1-meter depth intervals were computed versus vertical wave numbers for the upper layer (5–320 m) and lower layer (320–1000 m) at each station. The power law coefficients of the spectra about the vertical wave number are between −5/3 and −3. These coefficients indicate that the temperature and salinity fluctuations are influenced by stratification as well as by turbulence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00875643
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  • 5
    Electronic Resource
    Electronic Resource
    Application of aerial photography to the study of small scale upper ocean phenomena (1980)
    Springer
    Pure and applied geophysics 119 (1980), S. 294-308 
    Details
    ISSN: 1420-9136
    Keywords: Aerial photography ; Ocean surface layer pollution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The industrial waste dumped 180 n. miles south of Galveston was monitored in July 1977 by water sampling, hydrographic measurements, acoustic tracking on board two vessels, and by aerial photography. The plume of the waste diffused vertically and horizontally. Photodensitometry of aerial photos of the plume showed lateral dispersion of the plume in agreement with two other methods: acoustic tracking of the waste suspensoid and transmissometer sampling. In addition, the method showed small scale features like the lateral and longitudinal variations in the photodensity, indicating the waste concentration. This waste concentration showed periodic changes in its axial distance, with the spectral peak at about 160 m wave length. It shows a sharp increase at the windward edge of the plume as do the acoustic records. This phenomenon is explained in terms of the shearing current near the surface together with vertical diffusion. The periodic change along the axis is explained in terms of the Langmuir circulation and in terms of internal ship waves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00877767
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  • 6
    Electronic Resource
    Electronic Resource
    Small scale turbulent diffusion determined with underwater flow visualization (1982)
    Springer
    Pure and applied geophysics 120 (1982), S. 758-771 
    Details
    ISSN: 1420-9136
    Keywords: Diffusion ; Turbulence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Dye plumes were generated at three depths in the seasonal thermocline between 7 and 11 m, 22 km south of Key West on 21 August 1980 and photographed at about 10 second intervals with an underwater camera system. Eleven pairs of consecutive pictures are analyzed to determine the mean current vertical shear and the width of the plumes by positioning reference points relative to the rod attached to the camera system. The relative distances of reference points are calibrated with the stereophotogrammetric method for one pair. The eddy diffusivity is calculated by use of a model of turbulent diffusion developed byTaylor (1921). Its values range from 5 to 25 cm2s−1 for the plume widths ranging from 33 to 132 cm. The Richardson number is calculated for each pair of pictures with the vertical density gradient estimated from temperature profiles. Its values are higher than the critical value of 0.25 except for one case. The diffusivity was higher by orders of magnitude than the molecular one and indicates the presence of turbulence together with billow like features of the plumes in spite of high Richardson numbers. This suggests that the billow turbulence might be caused by effects of surface gravity waves and not by the Kelvin-Helmholtz instability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876658
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  • 7
    Electronic Resource
    Electronic Resource
    Inflow and outflow in a rotating circular container—A laboratory model for the Loop Current of the Gulf of Mexico (1979)
    Springer
    Pure and applied geophysics 117 (1979), S. 943-957 
    Details
    ISSN: 1420-9136
    Keywords: Oceanography ; Dish pan experiments ; Dynamics of oceans ; Laboratory modellings of ocean currents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The Loop Current of the Gulf of Mexico is simulated in the laboratory. A circular tank is filled with water and is placed off-center on a rotating table and the flow field is generated by injecting and withdrawing water at two openings on the wall. The free surface becomes parabolic due to balance of gravitational and centrifugal forces, simulating the latitudinal change of the Coriolis parameter (β-effect) in the ocean. The flow characteristics depend on the influx and the rate of rotation and can be classified according to non-dimensional parameters (Rossby, Ekman and Froude numbers denoted byR 0,E andF, respectively). When the influx is small and the rotation rate is large (smallR 0,E andF) the flow will be almost linear, and the fluid flows along the side-wall boundary layer under constraint of the β-effect. For a very large influx (largeR 0 andE) inertial forces become very large compared to the Coriolis force and the flow behaves like a potential flow. The flow studied had characteristics between these two extreme cases and hasR 0 andF similar to the Gulf circulation, though similarity inE is ambiguous. Photographs of the flow indicate that the inflow penetrates further into the interior when the rotation rate is increased while the influx is kept constant. The numerical analysis of the non-linear vorticity equation confirms this for the parameters corresponding to the experiment. In addition, the photographs reveal eddies embedded on both sides of the main stream, particularly near the inflow region. These eddies are intensified and become uniform in size as the influx increases. It is pointed out that such eddies were actually observed near the Loop Current north of the Yucatan Straits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876078
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  • 8
    Electronic Resource
    Electronic Resource
    Boundary layer models of ocean floor spreading (1971)
    Springer
    Pure and applied geophysics 85 (1971), S. 324-353 
    Details
    ISSN: 1420-9136
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Summary The equations of conservations of momentum and energy scaled with the characteristic values of the mantle indicate the presence of the upper boundary layer to produce the estimated rate of the ocean floor spreading by convection and the importance of the frictional heating. The depth of the upper boundary layer can be estimated from the balance of the viscous force with the horizontal pressure gradient at the sea floor. It is of the orders of 100 km and becomes deeper for the Pacific than for the Atlantic Ocean and also with frictional heating than without it. The frictional heating increases the surface heat flow of the heat conduction by ten to twenty percent for the Pacific Ocean but only by a few percent for the Atlantic Ocean. The similarity solutions are determined for the temperature and horizontal velocity in the upper boundary layer. These solutions are expressed in power series of the variabley x −n , wherex, y, andn are horizontal and vertical coordinates and numerical constant, respectively. Both temperature and horizontal velocity within the boundary layer are higher for the Pacific than for the Atlantic Ocean. When a larger viscosity is applied, it causes the increase of horizontal velocity below the surface because of the surface boundary conditions of the finite velocity and of vanishment of the velocity shear. The higher horizontal velocity generates higher temperature because it advects hotter material from the mid-ocean ridge site. The direct effect of frictional heating on the temperature distribution of the similarity solution is almost negligible, since the shear zone is deep and near the lower boundary of the upper boundary layer. In the similarity solution, the surface heat flow which is increased by the frictional heating is given as the boundary value. The effect of the frictional heating is important below the mid-ocean ridge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00875419
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  • 9
    Electronic Resource
    Electronic Resource
    Über dieneighbour diffusivity im Ozean (1960)
    Springer
    Ocean dynamics 13 (1960), S. 13-23 
    Details
    ISSN: 1616-7228
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Description / Table of Contents: Summary The relationship between neighbour diffusivity and the mean square of the separation of parts of particles are under certain conditions derived from the solution of the neighbour diffusion equation. The 4/3 power law, satisfied by the neighbout diffusivity in the ocean over a range of 10 cm to 108 cm, is proved by deduction from a theory of turbulent diffusion of two particles. The ordinary eddy diffusivity is obtained from observations of spread of dye and other substances in the ocean and is compared with the neighbour diffusivity.
    Abstract: Résumé La relation entre laneighbour diffusivity et le carré moyen de la séparation de particules est à certaines conditions dérivée de la solution de l'équation de laneighbour diffusivity. La loi de la puissance de quatre tiers, qui est vérifiéc pour des étendues de 10 à 108 cm par laneighbour diffusivity en océan, découle de la théorie de la diffusion turbulente de deux particules. L'eddy diffusivity ordinaire, déterminée à l'aide des observations concernant la distribution de teintures ou, d'autres matières introduites dans la mer, est comparée à laneighbour diffusivity.
    Notes: Zusammenfassung Die Beziehung zwischenneighbour diffusivity und dem mittleren Quadrat des gegenseitigen Abstands von Teilchenpaaren leitet sich von der Lösung derneighbour diffusion-Gleichung unter bestimmten Bedingungen ab. Das 4/3-Potenz-Gesetz, das durch dieneighbour diffusivity im Ozean innerhalb eines Bereichs von 10 cm bis 108 cm bestätigt wird, ergibt sich aus einer Theorie der Turbulenzdiffusion von zwei Teilchen. Die gewöhnlicheeddy diffusivity wurde durch Beobachtungen über die Ausbreitung von Farbe und anderen Substanzen im Ozean erhalten und wird mit derneighbour diffusivity vergleichen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02224732
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  • 10
    Electronic Resource
    Electronic Resource
    Barotropic disturbances caused by a point storm in aβ-plane ocean (1976)
    Springer
    Journal of oceanography 32 (1976), S. 33-47 
    Details
    ISSN: 1573-868X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract Barotropic equation for vorticity balance in theβ-plane is solved for a volume transport stream function with a northward moving wind stress torque concentrated at a point (tweak). Asymptotic techniques are applied to the solution expressed by Fourier type integrals. In the front zone (northern half from the tweak) the stream function behaves asO(¦X¦−5) whereX is a scaled eastward coordinate. In the wake, the stream function behaves asO(¦X¦−1/2) within a wedge bounded by the westward axis and a line directed SSE approximately, but behaves asO(¦X¦−5) in the rest of the half plane. On these boundaries it behaves asO(¦X¦−5/2) andO(¦X¦−1/3), respectively. East-west asymmetry is a result of asymmetry in zonal propagation of the planetary waves, which also cause the wavy pattern of the streamline in the western half of the wake. Friction is most effective in decreasing the stream function in the south to SSW sector and least effective to the west. Effect of divergence changes the wave pattern in the western half of the wake but does not change magnitude of the stream function. It is speculated that abnormal changes in daily mean sea levels observed in 1965 to 1971 along the south coast of Japan may be caused by the wake effect of moving typhoons east off Japan.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02107654
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