On the energy spectra of a random field of internal waves

In this paper, we study bifurcation structures of period-adding phenomena in an internal wave model that is a mathematical model for ocean internal waves. It has been suggested that chaotic solutions observed in the internal wave model may be related to the universal property of the energy spectra of ocean internal waves. In numerical bifurcation analyses of the internal wave model, we illustrate bifurcation routes to chaos and parameter regions where chaotic behavior is observed. Furthermore, it is found that the chaotic solutions are related to the period-adding sequence, that is, successive generations of periodic solutions with longer periods as a control parameter is changed. Considering the period-adding sequence as successive local bifurcations, we discuss a mechanism of the phenomena from the viewpoint of bifurcation analysis. We also consider similarity between period-adding phenomena in the internal wave model and ones in the Lorenz model.

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The coupling of wind and internal waves: modulation and friction mechanisms

Journal of Fluid Mechanics ◽

10.1017/s0022112094003605 ◽

1994 ◽

Vol 278 ◽

pp. 33-62 ◽

Cited By ~ 13

Author(s):

V. N. Kudryavtsev

Keyword(s):

Random Field ◽

Internal Waves ◽

Joint Action ◽

Friction Mechanisms ◽

Wind Waves ◽

Spontaneous Generation ◽

Inertial Oscillations ◽

Feedback Mechanisms ◽

Strong Winds ◽

Ekman Current

The interaction between internal waves (IW) and wind waves (WW) is studied. Three types of interaction are considered: spontaneous IW generation by a random field of WWs, and two feedback mechanisms - modulation and friction.The latter mechanism has not been studied before. Its influence on the IW-WW coupling is of primary importance. The modulation and friction mechanisms result in exponential attenuation of the IWs. Attenuation of IWs propagating against wind is the strongest. The IW attenuation has a dimensionless decrement of order 10-3, whereas for storm winds it attains the value of 10-2. Joint action of the spontaneous generation of IWs and their attenuation due to feedback mechanisms permits a stationary ‘wind-IW’ spectrum to exist. For strong winds the ‘wind-IW’ energy is of order 105 erg cm-2. The effect of IWs on currents in the ocean's upper layer is considered. Momentum and energy lost by IWs due to their interaction with WWs generates inertial oscillations. Under the attenuation of intensive IWs, the amplitude of inertial oscillations may be compared with the background Ekman current.

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Propagation and interaction of non-linear surface and internal waves in a two-layer fluid

International Journal of Multiphase Flow ◽

10.1016/s0301-9322(97)88503-5 ◽

1996 ◽

Vol 22 ◽

pp. 138

Author(s):

S Korsunsky

Keyword(s):

Internal Waves ◽

Non Linear

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Comparison of random field strengths in (1-x)SrTiO3-xBiFeO3 and (1-x)SrTiO3-xBaTiO3 relaxor ferroelectrics by means of acoustic emission

The European Physical Journal Applied Physics ◽

10.1051/epjap/2020200075 ◽

2020 ◽

Vol 92 (2) ◽

pp. 20401

Author(s):

Evgeniy Dul'kin ◽

Michael Roth

Keyword(s):

Acoustic Emission ◽

Random Field ◽

Electric Fields ◽

Bias Field ◽

Relaxor Ferroelectrics ◽

External Bias ◽

Field Strengths

In relaxor (1-x)SrTiO3-xBiFeO3 ferroelectrics ceramics (x = 0.2, 0.3 and 0.4) both intermediate temperatures and Burns temperatures were successfully detected and their behavior were investigated in dependence on an external bias field using an acoustic emission. All these temperatures exhibit a non-trivial behavior, i.e. attain the minima at some threshold fields as a bias field enhances. It is established that the threshold fields decrease as x increases in (1-x)SrTiO3-xBiFeO3, as it previously observed in (1-x)SrTiO3-xBaTiO3 (E. Dul'kin, J. Zhai, M. Roth, Phys. Status Solidi B 252, 2079 (2015)). Based on the data of the threshold fields the mechanisms of arising of random electric fields are discussed and their strengths are compared in both these relaxor ferroelectrics.

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