Laboratory Experiments of Lagrangian Motions in a Steady Baroclinic Wave

Tajima, T.; Nakamura, Teruya; Kuroda, T.

doi:10.2151/jmsj1965.73.1_37

Cited by 6 publications

(9 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As in the f -plane experiment, the regular eddy features seen with oppositely sloping endwalls in the present system consist of a series of closed, compact, oval anti-cyclonic eddies ͑at the upper level͒. The vortex character of these essentially baroclinic eddies not only suggests that fluid may be trapped for extended periods within their stagnant core, 36,44 but also that the dispersion of the individual wave components expected from the linear perturbation theory of Hide 45 is being effectively suppressed by nonlinear interactions between the various competing wave modes. Further departures from this linear theory are indicated by the profound asymmetry between the regular wave regimes of the ‫ץ‬D/‫ץ‬rϾ0 and ‫ץ‬D/‫ץ‬rϽ0 endwall experiments, with regular modes mϭ1 to 5 being observed with the former boundary arrangement, but only the mode mϭ1 being observed with the latter configuration.…”

Section: Discussionsupporting

confidence: 53%

Experiments on the structure of baroclinic waves and zonal jets in an internally heated, rotating, cylinder of fluid

Read

1998

Physics of Fluids

View full text Add to dashboard Cite

In this paper we report a laboratory investigation of the motion within a rotating cylinder of fluid subject to internal heating and to cooling at the outer cylindrical sidewall. The internal heating is supplied by ohmic dissipation as an electric current passes between the outer sidewall and an axial wire. The experiments focus on the formation of eddy features and the associated zonal jets. To identify how the flow regimes generated in this continuously forced system are modified by the presence of a radial depth gradient, experiments have been performed with both horizontal (f-plane) and oppositely sloping boundaries. Endwall configurations which cause the fluid depth (D) to increase with radius (∂D/∂r>0) and to decrease with radius (∂D/∂r<0) have been studied, as the former is applicable to the terrestrial atmosphere and oceans, while the latter may be relevant to deep atmospheres such as those of the giant planets and even planetary interiors. Stable, coherent, regular eddy features are observed over a wide range of rotation rates (Ω) in both horizontal and oppositely sloping endwall experiments. In the f-plane experiments regular modes with azimuthal wavenumbers m=1 and m=2 are observed. The regular wave regime of the ∂D/∂r>0 endwall experiments consists of modes with azimuthal wavenumbers m=1 to 5. Only the mode m=1 is seen in the regular wave regime of the ∂D/∂r<0 endwall experiments. The regular eddy structures produced in the ∂D/∂r>0 (∂D/∂r<0) endwall experiments are seen to be “vertically trapped” close to the bottom (top) boundary, whilst the amplitude of the f-plane modes is found not to vary substantially with depth. Further effects of the radial depth gradient are the observed reduction in the lateral scale of the eddy features in the ∂D/∂r>0 endwall experiments, which leads to the formation of between two and three independent trains of eddies within the lateral domain at sufficiently high values of Ω. Within the non-axisymmetric flow regimes of all three endwall configurations the number of zonal jets observed in the lateral domain of the experiment is larger than expected from the form of the background thermal forcing. The radial scale of the multiple zonal jets seen in the oppositely sloping boundary experiments is, however, much larger than a barotropic Rhines scale Lβ, suggesting that Lβ cannot be used to predict the radial wavenumber of the zonal mean flow in this continuously forced system.

show abstract

Section: Discussionsupporting

confidence: 53%

Experiments on the structure of baroclinic waves and zonal jets in an internally heated, rotating, cylinder of fluid

Read

1998

Physics of Fluids

View full text Add to dashboard Cite

show abstract

“…As was found in SY and experimentally in our previous paper (Tajima et al, 1995a(Tajima et al, , 1995b, the structure of vortices is composed of a core region, which is rather well isolated, and next to the core, a transition zone (sometimes called a separatrix layer in the papers concerning a chaotic advection (cf. Weiss and Knobloch, 1989)) where fluid particles are frequently transported to and from its outside, but rarely to the core.…”

Section: Observed Trajectoriessupporting

confidence: 63%

“…Sugata and Yoden (1994), hereafter referred to as SY, investigated the Lagrangian motion in a steady baroclinic wave of wavenumber-5 by tracing a marked fluid particle for a long time in a numerical solution of their model (Sugata and Yoden, 1993). As was schematically shown in our previous papers (Tajima and Nakamura, 1995;Tajima et al, 1995aTajima et al, , 1995b, the steady baroclinic wave has been well known to have the following basic structure: the upper (UJ, eastward)-and lower (U, Jwestward)-level jets, the high (HV)-and low (LV)-pressure vortices, and the inner (TB)-, outer (OB)-and lower (LB)-boundary layers. Based on this structure, Sugata and Yoden calculated the residence time of the fluid particle in each region and the transition matrix which expresses frequencies of transitions between the regions.…”

Section: Introductionmentioning

confidence: 99%

“…The apparatus and experimental procedures 2.1 Overall view o f apparatus A schematic of the present apparatus (Tajima et al, 1995a(Tajima et al, , 1995b) is illustrated in Fig. 1.…”

Section: Introductionmentioning

confidence: 99%

“…An annular glass tank ( Fig. 2; see Tajima et al (1995a) for the detailed explanation of its thermal control system.) is placed at the center of a small upper turntable which is rotated at an angular velocity f Measuring instruments, such as videocameras and an ultraviolet light projector are mounted on the large lower turntable.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experimental Observations of 3-D Lagrangian Motion in a Steady Baroclinic Wave

Tajima

Nakamura

Kurokawa

1997

Journal of the Meteorological Society of Japan

Self Cite

View full text Add to dashboard Cite

Chaotic Lagrangian motion in a steady baroclinic wave, which is highly relevant to meteorological and oceanographical problems, was investigated by Sugata and Yoden (1994) by tracing a marked fluid particle for a long time in a numerical solution of their model. To test their result, we have conducted experiments on steady Baroclinic waves in a differentially-heated rotating fluid annulus by tracking a 3-D trajectory of one neutrally buoyant tracer particle suspended in the fluid for a long time. We show here four trajectories that have been analyzed up to now. In the wavenumber-5 wave, the observed trajectories include the preferred routes of region transitions expected from the numerical investigation. This supports the Lagrangian view of the heat transport presented by Sugata and Yoden: The jet absorbs a large number of hot fluid particles from the outer boundary layer and releases them in the inner boundary layer, while the fluid particles nearly conserve their temperature in the meandering jet. Furthermore, it is of great interest that there was found one event of region transtion which does not take place in the numerical simulation. In the wavenumber-4 wave, however, the tracer particle was observed to remain trapped within the jet for a long time. This leads to the orthodox view of the heat transport: The jet absorbs a large amount of heat from the outer boundary and releases it into the inner boundary so that heating and cooling of the fluid particles take place during every cycle of the meander of the jet.

show abstract

General Circulation of Planetary Atmospheres

Read

Pérez

Moroz

et al. 2014

Modeling Atmospheric and Oceanic Flows

View full text Add to dashboard Cite

In engineering and the applied sciences, the term "model" is typically used to denote a device or concept that imitates the behavior of a physical system as closely as possible, but on a different (usually smaller) scale, possibly with some simplifications. The aim of such a model is normally to evaluate the performance of such a system for reasons connected with its exploitation for economic, social, military, or other purposes. In the context of the atmosphere or oceans, numerical weather and climate prediction models clearly fall into this category. Such models are extremely complicated entities that seek to represent the topography, composition, radiative transfer, and dynamics of the atmosphere, oceans, and surface in great detail. As a result, it is generally impossible to comprehend fully the complex interactions of physical processes and scales of motion that occur within any given simulation. The success of such models can only be judged by the accuracy of their predictions as directly verified (in the case of numerical weather prediction) against subsequent observations and measurements. Similar models used for climate prediction, however, are often comparable in complexity to those used for weather prediction but are frequently used as tools in attempts to address questions of economic, social, or political importance (e.g., concerning the impact of increasing anthropogenic greenhouse gas emissions) for which little or no verifying data may be available.In formulating such models and interpreting their results, it is necessary to make use of a different class of

show abstract

Laboratory Experiments of Lagrangian Motions in a Steady Baroclinic Wave

Cited by 6 publications

References 9 publications

Experiments on the structure of baroclinic waves and zonal jets in an internally heated, rotating, cylinder of fluid

Experiments on the structure of baroclinic waves and zonal jets in an internally heated, rotating, cylinder of fluid

Experimental Observations of 3-D Lagrangian Motion in a Steady Baroclinic Wave

General Circulation of Planetary Atmospheres

Contact Info

Product

Resources

About