Laboratory simulation of Jupiter's Great Red Spot

Sommeria, Joël; Meyers, Steven D.; Swinney, Harry L.

doi:10.1038/331689a0

Cited by 178 publications

(94 citation statements)

References 17 publications

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“…However, Eq. (2) may not be very appropriate when we investigate the diffusion of dye locally injected in laboratory experiments, an example of which is that on vortices and Rossby waves in eastward and westward jets by Sommeria et al (1988Sommeria et al ( , 1989Sommeria et al ( , 1991. It is neccesary to consider the random processes due to molecular motions explicitly by introducing a stochastic forcing term.…”

Section: Discussionmentioning

confidence: 99%

Chaotic Lagrangian Motion and Heat Transport in a Steady, Baroclinic Annulus Wave

Sugata

Yoden

1994

Journal of the Meteorological Society of Japan

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Lagrangian motion in a steady, Baroclinic annulus wave is investigated numerically by following a tracer particle trajectory for a long period. Even for the regular Eulerian flow field of steady waves, the trajectory shows a chaotic nature, which is an example of "Lagrangian turbulence". However, the chaotic trajectory has some organized structures depending on its position in the annulus. Based on the structure, the annulus of fluid is divided into the following regions: the upper-level and lower-level jets, the cyclonically and anticyclonically trapped regions, and the inner, outer and lower boundary layers. Some isolated regions in which the marked particle has never stayed for that period are also found inside the cyclonically trapped region and around the anticyclonically trapped region. Statistics over the long period show a preferred cyclic route of the region transitions: the outer boundary layer-the upper-level jet -the inner boundary layer-the lower-level jet or the lower boundary layer-the outer boundary layer. The number of dwell periods of the particle in the trapped regions is much smaller than that in the cyclic route, but the average time of one stay in the trapped regions is longer.A Lagrangian view of the heat transport in the steady annulus wave is obtained: The fluid particle absorbs a large amount of heat in the outer boundary layer and releases it in the inner boundary layer, while it nearly conserves its temperature in the interior regions. Inward heat transport is small in every one cycle of the meander of the jets.

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Section: Discussionmentioning

confidence: 99%

Chaotic Lagrangian Motion and Heat Transport in a Steady, Baroclinic Annulus Wave

Sugata

Yoden

1994

Journal of the Meteorological Society of Japan

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“…1-4 indicate that some geomorphological features associated with liquid flows may be duplicated on the laboratory scale with dry grains by suitably reducing R st . Similar scaling arguments have been applied to extrapolate laboratory fluid experiments to geophysical scales (26) and to relate laboratory granular experiments to extraterrestrial craters (27). Even more germane, scaling using a ratio between settling and debris flow speeds has been reported in terrestrial particle-laden oceanic and volcanic flows (28,29).…”

Section: Scalingmentioning

confidence: 99%

Dry granular flows can generate surface features resembling those seen in Martian gullies

Shinbrot

Duong

Kwan

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

114

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Over the past decade or more, contradictory evidence of Martian climate, indicating that surface temperatures seldom if ever approach the melting point of water at midlatitudes, and geomorphic features, consistent with liquid flows at these same latitudes, have proven difficult to reconcile. In this article, we demonstrate that several features of liquid-erosional flows can be produced by dry granular materials when individual particle settling is slower than characteristic debris flow speeds. Since the gravitational acceleration on Mars is about one-third that on Earth, and since particle settling speeds scale with gravity, we propose that some (although perhaps not all) Martian geomorphological features attributed to liquid flows may in fact be associated with dry granular flows in the presence of reduced gravity.A number of recent studies have investigated evidence for liquid water on Mars. Much of the available evidence has concerned recent, or even contemporary (1), geomorphological features, such as eroded channels and gullies that are common signatures of terrestrial water flow (2-4). This evidence is difficult to reconcile (5-7) with surface temperatures on Mars, which seldom exceed Ϫ50°C at latitudes and locations where these features are often found (6,8). This paradox persists despite recent Mars Rover data supporting the case for ancient surface water. Several authors have proposed possible resolutions to this contradiction (9-12), notably a recent analysis suggesting that some liquid-like flow features in Martian gullies may instead be associated with dry granular flow (1). In this article, we observe that gravity on Mars is 38% that on Earth (13), and behaviors of dry grains at reduced gravitational acceleration have never, to our knowledge, been catalogued. As we will show, reduced gravity has the effect of prolonging fluidization of particle flows by decreasing particle settling speeds as compared with debris flow speeds. We present data demonstrating that many features that have been attributed to liquid flow in Martian gullies can indeed be reproduced in terrestrial laboratory experiments designed to mimic reduced gravity.Our point of departure is the observation that the speed at which small dry particles (14) settle in a gas can be approximated by the Stokes settling relation:whereas the terminal speed that large debris flows can reach while flowing through a gas is bounded by (15):Here g and g are the gas density and viscosity, d, s , and C s are characteristic particle diameter, density, and drag coefficient, g is gravitational acceleration, and D gives the scale of the debris flow (16). These relations are only correct to the lowest order; however, they illustrate that, all other things being equal, particle settling speeds go as g, whereas debris flow speeds go as ͌ g. We stress that nothing is profound about the difference between these relations, which simply reflect the fact that particles, being small, settle at a low Reynold's number, whereas debris flows, being large, travel at a hi...

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“…Striking examples are the persistent atmospheric vortices in the giant planets like Jupiter's Great Red Spot (Ingersoll 1990). This phenomenon can be reproduced in laboratory experiments (Sommeria et al 1988;Nezlin & Snezhkin 1993) and explained in terms of statistical mechanics of two dimensional turbulence (Sommeria et al 1991;Miller et al 1992).…”

Section: Planet Formation: Different Scenariosmentioning

confidence: 99%

Reshaping the outskirts of planetary systems

Marcos

2001

A&A

111

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Abstract. We present N-body calculations of the orbital evolution of a test population of primordial EdgeworthKuiper Belt objects (EKBOs) in a star cluster submitted to the gravitational perturbations of other cluster members, both single stars and binaries. In order to provide initial conditions for the EKBO test population, three original orbital distributions (eccentricity and semi-major axis) are considered. The first resembles a conventional model of the evolution of the solar nebula with eccentricity, e = 0.01 and semi-major axis uniformly distributed in the range 35-60 AU. The second distribution considers the stage of planet formation after Neptune's outward migration with concentration of solid particles at 39 AU and e ∼ 0.1−0.3. The third distribution is taken from a non-collisional, two-dimensional simulation of a gaseous protoplanetary disk in which solid particles beyond 60 AU are perturbed by the growing proto-planets, Uranus and Neptune. Metric particles are trapped in an outer resonance with radial distance of about 48.5 AU and eccentricity of 0.16. Stellar encounters lead to significant modification of the primordial orbital distribution only if the Sun was born in a typical open cluster but not in an association. Our results suggest that the observed orbital distribution of the scattered EKBOs may be the result of these multi-body gravitational interactions in the Sun's parent star cluster. On the other hand, the circular shape of the Edgeworth-Kuiper Belt-like structure found around Eridani indicates that this star was born in a small cluster or association.

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Laboratory simulation of Jupiter's Great Red Spot

Cited by 178 publications

References 17 publications

Chaotic Lagrangian Motion and Heat Transport in a Steady, Baroclinic Annulus Wave

Chaotic Lagrangian Motion and Heat Transport in a Steady, Baroclinic Annulus Wave

Dry granular flows can generate surface features resembling those seen in Martian gullies

Reshaping the outskirts of planetary systems

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