Mesoscale eddy characteristics in the Labrador Sea from observations and a 1/60° numerical model

2020 ◽  
Author(s):  
Arne Bendinger ◽  
Johannes Karstensen ◽  
Julien Le Sommer ◽  
Aurélie Albert ◽  
Fehmi Dilmahamod
Keyword(s):  
Solid Body ◽  
Inner Core ◽  
Velocity Structure ◽  
Mesoscale Eddy ◽  
Skill Assessment ◽  
Labrador Sea ◽  
Body Rotation ◽  
Data Set ◽  
Solid Body Rotation ◽  
Eddy Characteristics

<p>Mesoscale eddies play an important role in lateral property fluxes. Observational studies often use sea level anomaly maps from satellite altimetry to estimate eddy statistics (incl. eddy kinetic energy). Recent findings suggest that altimetry derived eddy characteristics may suffer from the low spatial resolution of past and current satellite-tracks in high-latitude oceans associated with small Rossby radii. Here we present results of an eddy reconstruction based on a nonlinear damping Gauss-Newton optimisation algorithm using ship based current profiler observations from two research expeditions in the Labrador Sea in 2014 and 2016. Overall we detect 14 eddies with radii ranging from 7 to 35 km.</p><p>In order to verify the skill of the reconstruction we used the submesoscale permitting NATL60 model (1/60°) as a reference data set. Spectral analysis of the horizontal velocity implies that the mesoscale regime is well represented in NATL60 compared with the observations. The submesoscale regime in the model spectra shows deviations to the observations at scales smaller than 10km near the ocean surface. The representation of the submesoscale flow further decreases in the model with increasing depth.</p><p>By subsampling the NATL60 model velocities along artificial ship tracks, applying our eddy reconstruction algorithm, and comparing the results with the full model field, a skill assessment of the reconstruction is done. We show that the reconstruction of the eddy characteristics can be affected by the location of the ship track through the velocity field.</p><p>In comparison with the observed eddies the NATL60 eddies have smaller radii and higher azimuthal velocities and thus are more nonlinear. The inner core velocity structure for observations and NATL60 suggests solid body rotation for 2/3 of the radius. The maximum azimuthal velocity may deviate by up to 50% from solid body rotation.</p><p>The seasonality of the submesoscale regime can be seen in the data as the power spectrum is reduced from spring to summer in both the ship-based measurements and model.</p>

Oval Flow Mode Between Two Corotating Disks With Stationary Shroud

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Ching Min Hsu ◽  
Jia-Kun Chen ◽  
Min Kai Hsieh ◽  
Rong Fung Huang
Keyword(s):  
Flow Structure ◽  
Solid Body ◽  
Circumferential Velocity ◽  
Body Rotation ◽  
Flow Core ◽  
Core Flow ◽  
Node Point ◽  
Solid Body Rotation ◽  
Characteristic Flow ◽  
Buffer Region

The characteristic flow behavior, time-averaged velocity distributions, phase-resolved ensemble-averaged velocity profiles, and turbulence properties of the flow in the interdisk midplane between shrouded two corotating disks at the interdisk spacing to disk radius aspect ratio 0.2 and rotation Reynolds number 3.01 × 105 were experimentally studied by flow visualization method and particle image velocimetry (PIV). An oval core flow structure rotating at a frequency 60% of the disks rotating frequency was observed. Based on the analysis of relative velocities, the flow in the region outside the oval core flow structure consisted of two large vortex rings, which move circumferentially with the rotation motion of the oval flow core. Four characteristic flow regions—solid-body-rotation-like region, buffer region, vortex region, and shroud-influenced region—were identified in the flow field. The solid-body-rotation-like region, which was featured by its linear distribution of circumferential velocity and negligibly small radial velocity, was located within the inscribing radius of the oval flow core. The vortex region was located outside the circumscribing radius of the oval flow core. The buffer region existed between the solid-body-rotation-like region and the vortex region. In the buffer region, there existed a “node” point that the propagating circumferential velocity waves diminished. The circumferential random fluctuation intensity presented minimum values at the node point and high values in the solid-body-rotation-like region and shroud-influenced region due to the shear effect induced by the wall.

scholarly journals On a possible corrugation of the galactic plane

1970 ◽  
Vol 38 ◽  
pp. 147-150 ◽  
Author(s):  
C. M. Varsavsky ◽  
R. J. Quiroga
Keyword(s):  
Brightness Temperature ◽  
Solid Body ◽  
Rotation Curve ◽  
Galactic Plane ◽  
Maximum Temperature ◽  
Body Rotation ◽  
Maximum Brightness ◽  
Solid Body Rotation ◽  
The Galaxy ◽  
Sinusoidal Pattern

We have studied the rotation curve of the Galaxy at different heights below and above the equator. In the course of this work we noticed that the maximum brightness temperature of hydrogen oscillates around the galactic plane following a fairly sinusoidal pattern. It is further noticed that the maximum temperature of hydrogen occurs right on the plane in the regions where the rotation curve has a form indicating solid body rotation. A rotation curve based on points of maximum hydrogen temperature does not differ appreciably from a rotation curve measured on the galactic plane.

Fragmentation of elongated cylindrical clouds. IV - Clouds with solid-body rotation about an arbitrary axis

1992 ◽  
Vol 400 ◽  
pp. 579 ◽  
Author(s):  
Ian Bonnell ◽  
Jean-Pierre Arcoragi ◽  
Hugo Martel ◽  
Pierre Bastien
Keyword(s):  
Solid Body ◽  
Body Rotation ◽  
Solid Body Rotation ◽  
Arbitrary Axis

scholarly journals Observations of an Inertial Peak in the Intrinsic Wind Spectrum Shifted by Rotation in the Antarctic Vortex

2012 ◽  
Vol 69 (12) ◽  
pp. 3800-3811 ◽  
Author(s):  
L. J. Gelinas ◽  
R. L. Walterscheid ◽  
C. R. Mechoso ◽  
G. Schubert
Keyword(s):  
Solid Body ◽  
Wave Spectrum ◽  
Polar Vortex ◽  
Relative Vorticity ◽  
Body Rotation ◽  
Background Flow ◽  
Absolute Vorticity ◽  
Solid Body Rotation ◽  
The Absolute ◽  
The Antarctic

Abstract Spectral analyses of time series of zonal winds derived from locations of balloons drifting in the Southern Hemisphere polar vortex during the Vorcore campaign of the Stratéole program reveal a peak with a frequency near 0.10 h−1, more than 25% higher than the inertial frequency at locations along the trajectories. Using balloon data and values of relative vorticity evaluated from the Modern Era Retrospective-Analyses for Research and Applications (MERRA), the authors find that the spectral peak near 0.10 h−1 can be interpreted as being due to inertial waves propagating inside the Antarctic polar vortex. In support of this claim, the authors examine the way in which the low-frequency part of the gravity wave spectrum sampled by the balloons is shifted because of effects of the background flow vorticity. Locally, the background flow can be expressed as the sum of solid-body rotation and shear. This study demonstrates that while pure solid-body rotation gives an effective inertial frequency equal to the absolute vorticity, the latter gives an effective inertial frequency that varies, depending on the direction of wave propagation, between limits defined by the absolute vorticity plus or minus half of the background relative vorticity.

Waves in a gas in solid-body rotation

1972 ◽  
Vol 56 (2) ◽  
pp. 277-286 ◽  
Author(s):  
J. B. Morton ◽  
E. J. Shaughnessy
Keyword(s):  
Eigenvalue Problem ◽  
Solid Body ◽  
Transverse Wave ◽  
Speed Of Sound ◽  
Acoustic Waves ◽  
Body Rotation ◽  
Perfect Gas ◽  
Solid Body Rotation ◽  
Rotational Waves

The axial and transverse wave motions of an inviscid perfect gas in isothermal solid-body rotation in a cylinder are investigated. Solutions of the resulting eigenvalue problem are shown to correspond to two types of waves. The acoustic waves are the rotational counterparts of the well-known Rayleigh solutions for a gas at rest in a cylinder. The rotational waves, whose amplitudes and frequencies go to zero in the non-rotating limit, exhibit phase speeds both larger and smaller than the speed of sound. The effect of rotation on the frequency and structure of these waves is discussed.

The Elastic Distortion of Rollers Under Combined Radial and Thrust Loads

1983 ◽  
Vol 105 (2) ◽  
pp. 189-197 ◽  
Author(s):  
H. So ◽  
R. Gohar
Keyword(s):  
Pressure Distribution ◽  
Solid Body ◽  
Axial Load ◽  
Axial Loading ◽  
Radial Pressure ◽  
Approximate Analysis ◽  
Body Rotation ◽  
Solid Body Rotation ◽  
Elastic Distortion ◽  
Radial Loading

This paper describes an approximate analysis for finding the elastostatic radial and end face distortion, radial pressure distribution, and solid body rotation of a flat ended axially profiled bearing roller under combined radial and axial loading through the ribs. It is found that a small but significant end face bulge occurs at each roller end when there is radial loading only. Upon the addition of an axial load, this bulge becomes a small depression. The altered geometry there may become significant during bearing operation, as it affects roller skew, wear, and lubrication between the ribs and roller and faces.

scholarly journals Solid Body Rotation Vibration

2014 ◽  
Vol 2 ◽  
pp. 38-39
Author(s):  
Kern E. Kenyon
Keyword(s):  
Solid Body ◽  
Short Distance ◽  
Wave Motion ◽  
Vertical Cylinder ◽  
Frame Of Reference ◽  
Body Rotation ◽  
Fluid Interface ◽  
Wave Type ◽  
Constant Frequency ◽  
Solid Body Rotation

For solid body rotation of an incompressible fluid inside a vertical cylinder (open to air at the top with gravity acting down) it is proposed that if a small piece of fluid is displaced horizontally and radially by a short distance and then released, it will oscillate with a constant frequency as viewed in the rotating frame of reference. The oscillation frequency is derived to be equal to the basic frequency of the solid body rotation. Also it is hypothesized that a wave type of motion of the solid body rotation should be possible at the air/fluid interface. Experimental verification is needed for the conjectured vibration and wave motion of the solid body rotation.

Effects of Solid Body Rotation on the Transport of Turbulence

1993 ◽  
pp. 369-381
Author(s):  
L. Shao ◽  
M. Michard ◽  
J. P. Bertoglio
Keyword(s):  
Solid Body ◽  
Body Rotation ◽  
Solid Body Rotation
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