Hamiltonian Dynamics of Coupled Potential Vorticity and Internal Wave Motion: 1. Linear Modes

1993 ◽  
Author(s):  
Henry D. Abarbanel ◽  
Ali Rouhi
Keyword(s):  
Internal Wave ◽  
Potential Vorticity ◽  
Wave Motion ◽  
Hamiltonian Dynamics

Density Wave Measurements in a Rectangular Clarifier

1983 ◽  
Vol 18 (1) ◽  
pp. 129-150 ◽  
Author(s):  
Mark K. Watson ◽  
R.R. Hudgins ◽  
P.L. Silveston
Keyword(s):  
Power Spectrum ◽  
Internal Wave ◽  
Internal Waves ◽  
Wave Motion ◽  
Wave Amplitude ◽  
Suspended Solids ◽  
Small Volume ◽  
Density Wave ◽  
Measure Concentration ◽  
Wave Measurements

Abstract Internal wave motion was studied in a laboratory rectangular, primary clarifier. A photo-extinction device was used as a turbidimeter to measure concentration fluctuations in a small volume within the clarifier as a function of time. The signal from this device was fed to a HP21MX minicomputer and the power spectrum plotted from data records lasting approximately 30 min. Results show large changes of wave amplitude as frequency increases. Two distinct regions occur: one with high amplitudes at frequencies below 0.03 Hz, the second with very small amplitudes appears for frequencies greater than 0.1 Hz. The former is associated with internal waves, the latter with flow-generated turbulence. Depth, velocity in the clarifier and inlet suspended solids influence wave amplitudes and the spectra. A variation with position or orientation of the probe was not detected. Contradictory results were found for the influence of flow contraction baffles on internal wave amplitude.

Internal wave motion in a periodic stratification

1979 ◽  
Vol 22 (10) ◽  
pp. 1862 ◽  
Author(s):  
Vincenzo Malvestuto
Keyword(s):  
Internal Wave ◽  
Wave Motion ◽  
Periodic Stratification

scholarly journals Small-Scale Potential Vorticity in the Upper-Ocean Thermocline

2019 ◽  
Vol 49 (7) ◽  
pp. 1845-1872 ◽  
Author(s):  
Ren-Chieh Lien ◽  
Thomas B. Sanford
Keyword(s):  
Internal Wave ◽  
Frequency Spectrum ◽  
Frequency Band ◽  
Potential Vorticity ◽  
Wave Frequency ◽  
Energy Ratio ◽  
Upper Ocean ◽  
Vertical Vorticity ◽  
Vertical Scales ◽  
Mode Energy

AbstractTwenty Electromagnetic Autonomous Profiling Explorer (EM-APEX) floats in the upper-ocean thermocline of the summer Sargasso Sea observed the temporal and vertical variations of Ertel potential vorticity (PV) at 7–70-m vertical scale, averaged over O(4–8)-km horizontal scale. PV is dominated by its linear components—vertical vorticity and vortex stretching, each with an rms value of ~0.15f. In the internal wave frequency band, they are coherent and in phase, as expected for linear internal waves. Packets of strong, >0.2f, vertical vorticity and vortex stretching balance closely with a small net rms PV. The PV spectrum peaks at the highest resolvable vertical wavenumber, ~0.1 cpm. The PV frequency spectrum has a red spectral shape, a −1 spectral slope in the internal wave frequency band, and a small peak at the inertial frequency. PV measured at near-inertial frequencies is partially attributed to the non-Lagrangian nature of float measurements. Measurement errors and the vortical mode also contribute to PV in the internal wave frequency band. The vortical mode Burger number, computed using time rates of change of vertical vorticity and vortex stretching, is 0.2–0.4, implying a horizontal kinetic energy to available potential energy ratio of ~0.1. The vortical mode energy frequency spectrum is 1–2 decades less than the observed energy spectrum. Vortical mode energy is likely underestimated because its energy at vertical scales > 70 m was not measured. The vortical mode to total energy ratio increases with vertical wavenumber, implying its importance at small vertical scales.

Internal wave motion in a non-homogeneous viscous fluid of variable depth

1971 ◽  
Vol 70 (1) ◽  
pp. 157-167 ◽  
Author(s):  
B. D. Dore
Keyword(s):  
Boundary Layer ◽  
Viscous Fluid ◽  
Internal Wave ◽  
Surface Waves ◽  
Wave Motion ◽  
Variable Depth ◽  
Boundary Layer Analysis ◽  
Layer Analysis ◽  
Method Of Solution ◽  
Progressive Waves

AbstractA method of solution is given to the problem of internal wave motion in a non-homogeneous viscous fluid of variable depth. The approach is based on the inviscid theory of Keller and Mow(l) and on boundary-layer analysis. For internal progressive waves in uniform depths, it reduces essentially to the theory given by Dore(2). The present results are also applicable to surface waves when the fluid is homogeneous.

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