dorsal/arxiv
View SchemaExperimental study of super-rotation in a magnetostrophic spherical Couette flow
| Authors | Henri-Claude Nataf, Thierry Alboussière, Daniel Brito, Philippe Cardin, Nadège Gagnière, Dominique Jault, Jean-Paul Masson, Denys Schmitt |
|---|---|
| Categories | |
| ArXiv ID | physics/0512217 |
| URL | https://arxiv.org/abs/physics/0512217 |
| DOI | 10.1080/03091920600718426 |
Abstract
We report measurements of electric potentials at the surface of a spherical container of liquid sodium in which a magnetized inner core is differentially rotating. The azimuthal angular velocities inferred from these potentials reveal a strong super-rotation of the liquid sodium in the equatorial region, for small differential rotation. Super-rotation was observed in numerical simulations by Dormy et al. [1]. We find that the latitudinal variation of the electric potentials in our experiments differs markedly from the predictions of a similar numerical model, suggesting that some of the assumptions used in the model - steadiness, equatorial symmetry, and linear treatment for the evolution of both the magnetic and velocity fields - are violated in the experiments. In addition, radial velocity measurements, using ultrasonic Doppler velocimetry, provide evidence of oscillatory motion near the outer sphere at low latitude: it is viewed as the signature of an instability of the super-rotating region.
{
"annotation_id": "d7aa7ba2-0c0c-4584-9712-10a9faca1d6f",
"date_created": "2026-03-02T18:01:03.857000Z",
"date_modified": "2026-03-02T18:01:03.857000Z",
"file_hash": "2807dbbfd25866838a376896fe36211cbd297bb5740d395d821fec882f58a988",
"private": false,
"record": {
"abstract": "We report measurements of electric potentials at the surface of a spherical\ncontainer of liquid sodium in which a magnetized inner core is differentially\nrotating. The azimuthal angular velocities inferred from these potentials\nreveal a strong super-rotation of the liquid sodium in the equatorial region,\nfor small differential rotation. Super-rotation was observed in numerical\nsimulations by Dormy et al. [1]. We find that the latitudinal variation of the\nelectric potentials in our experiments differs markedly from the predictions of\na similar numerical model, suggesting that some of the assumptions used in the\nmodel - steadiness, equatorial symmetry, and linear treatment for the evolution\nof both the magnetic and velocity fields - are violated in the experiments. In\naddition, radial velocity measurements, using ultrasonic Doppler velocimetry,\nprovide evidence of oscillatory motion near the outer sphere at low latitude:\nit is viewed as the signature of an instability of the super-rotating region.",
"arxiv_id": "physics/0512217",
"authors": [
"Henri-Claude Nataf",
"Thierry Alboussi\u00e8re",
"Daniel Brito",
"Philippe Cardin",
"Nad\u00e8ge Gagni\u00e8re",
"Dominique Jault",
"Jean-Paul Masson",
"Denys Schmitt"
],
"categories": [
"physics.geo-ph"
],
"doi": "10.1080/03091920600718426",
"title": "Experimental study of super-rotation in a magnetostrophic spherical Couette flow",
"url": "https://arxiv.org/abs/physics/0512217"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "6278d50d-6848-4afb-a217-f81e1ca63449",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}